Solved Book 1
Solved Book 1
Date: 19.12.2009 Timings: 0930-1230 HRS Duration: 3 HRS Max. Marks: 150
General instructions:
o Please check that this question paper contains 12 printed pages
o Please check that this question paper contains 64 questions
o The question paper is divided into three sections
o All questions in all three sections are compulsory
o All parts of a question should be answered at one place
1 To maximize the combustion efficiency, which of the following in the flue gas needs to be
done?
1
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
5 Propane is an example of
a) increases b) decreases
c) remains the same d) depends on the shape of the body
9 How much carbon emission will be reduced per year by replacing 60 Watt incandescent
lamp with 15 Watt CFL Lamp, if emission per unit is 1 kg CO2 per kWh and annual burning
is 3000 hours?
13 An energy audit as defined in the Energy Conservation Act 2001 does not include
2
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
3
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
d) it is a disincentive for Distribution Company
25 Which of the following will be true of load factor for a continuous process
4
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
a) 1 b) 0 c) 10 d) 100
5
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
S-1 Explain the difference between contract demand and maximum demand.
Ans
Contract Demand
Contract demand is the amount of electric power that a customer demands from
utility in a specified interval. Unit used is kVA or kW. It is the amount of electric
power that the consumer agreed upon with the utility. This would mean that utility
has to plan for the specified capacity.
(2.5 Marks)
Maximum Demand
Maximum demand is the highest average kVA recorded during any one-demand
interval within the month. The demand interval is normally 30 minutes, but may
vary from utility to utility from 15 minutes to 60 minutes. The demand is measured
using a tri-vector meter / digital energy meter.
(2.5 Marks)
S-2 An induction motor draws 8 kW with a lagging reactive power of 4 kVAr.
Calculate the operating power factor of the motor.
kW
Ans. Power factor =
(kW ) 2 (kVAr ) 2
(2 Marks)
8
=
(8) 2 ( 4) 2
6
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
= 0.905
(3 Marks)
Ans Sulphur dioxide (SO2), nitrous oxide (NOX) and carbon monoxide (CO) and
Carbon Dioxide are major emissions from combustion of fossil fuels. SO2
and NOx lead to acid rain. CO is unstable and toxic. CO2 is a green house
gas, which leads to global warming.
(5 Marks)
S-4 Fuel substitution may not always result in energy savings. Explain with an
example.
Ans Let us say we are replacing an oil fired boiler by a wood fired boiler for
economic reasons. The losses in wood fired boiler may be more and hence
to compensate for that we need to supply more energy for the same output.
Thus it will increase the energy consumption.
(5 Marks)
Ans
S-6 The initial temperature of 150g of ethanol was 22oC. What will be the final
temperature of the ethanol if 3240 J was needed to raise the temperature of the
ethanol? (Specific heat capacity of ethanol is 2.44 J/goC).
S-7 Explain the importance of TOD (time of the day) tariff and its advantage to
utilities and to users. List some of the Industries where TOD benefits can be
fully utilised.
Ans Many electrical utilities like to have flat demand curve to achieve high
plant efficiency. They encourage user to draw more power during off-peak
hours (say during night time) and less power during peak hours. As per
their plan, they offer TOD Tariff, which may be incentives or disincentives.
Energy meter will record peak and non-peak consumption separately by
timer control. TOD tariff gives opportunity for the user to reduce their
billing, as off peak hour tariff charged are quite low in comparison to peak
hour tariff.
(3 Marks)
a. Operation of additional Cement Mills in Night periods
b. Operation of Melting furnaces in night shift
c. Heat treatment furnace operation in Night shift
d. Storage pump operation in large complex in night shift
(2 Marks)
S-8 Explain why a project with a high IRR is not necessarily more attractive than a
project with lower IRR?
Ans The IRR can not be distinguished between lending and borrowing and
hence a high IRR is not necessarily a desirable feature.
Also the NPV is the increase in shareholder or companies wealth through
the project. It therefore can happen that a project A has a very high IRR
but low NPV; while another Project B has low IRR but High NPV .In this
case B should be selected
(5 Marks)
L-1 Steam flow from a water tube boiler is measured by measuring the feed water
tank levels. In two hours there is a drop of 200 cm in level. The cross sectional
area of the tank is 9 m2. Assuming no blowdown, calculate the steam flow rate.
The enthalpy of steam is 662 kCal/kg and feed water temperature is 80oC.
The calorific value of fuel used in the above boiler was measured by a
continuous flow calorimeter. The following data were obtained.
= 19440 kcal
= 22871 kcal
= 10,164 kcal/kg
(5 Marks)
(b) Volume of flow in 2 hours = 9 x 2m
= 18 m3
Steam flow rate = 18/2 = 9 TPH
Fuel firing rate = 9000 kg/hr x (662-80)/(0.85 x 10164)
= 606.29 kg/hr
(5 Marks)
Hence the decision rule associated with the net present value criterion is:
“Accept the project if the net present value is positive and rejects the
project if the net present value is negative”.
Therefore the project is acceptable.
(2 Marks)
L-3 What is Energy Security? Mention few strategies countries adopt to ensure this?
Ans. The basic aim of energy security for a nation is to reduce its dependence
on the imported energy sources for its economic growth.
(2 marks)
9
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
Some of the strategies for energy security are:
Ans (i)
E
B3
3
A B
5 G
1 2 3 D F 5 6
3
4 C
4 4
2
E
[3 marks]
D1 and D2 are dummy activities
A- B- D- F- G
Early start (ES), Early Finish (EF), Latest start (LS), Latest finish (LF)
10
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
(6 marks)
L-5 A 500 MW coal plant based on conventional pulverized fuel has a gross
efficiency of 38%. The Gross calorific value of the coal used is 4000 kCal/kg
with 40% total carbon. A supercritical unit of 500 MW replaces the plant with a
gross efficiency of 40% using the same characteristic coal. Calculate the
following
= 112000 tonnes
[7 marks]
11
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
L-6 (a) When the same quantity of heat is added to the same mass of Iron and
copper pieces, the temperature of Iron piece rises by 15 OC. Calculate the
rise in temperature of Copper piece, if the specific heat of Iron is 470 J/kgoC
and that of Copper is 390 J / kg oC?
(b) The input to a textile dryer is 60 kg of wet cloth per hour with 55% moisture.
If it is dried to 10% in a dryer, estimate the moisture removed per hour.
Ans Mass of Iron x Sp. Heat Iron x 15 OC = Mass of Copper x Sp. Heat Copper
(a) x (Rise in Temp of Copper OC)
Since mass of Iron = Mass of Copper
Sp. Heat Iron x 15 OC = Sp. Heat Copper x (Rise in Temp of Copper OC
Sp. Heat of Iron = 470 J / kg OC
Sp. Heat of Copper = 390 J / kg OC
Hence, Rise in Copper Temp. = (470 x 15 ) / 390
= 18.08 OC
[5 marks]
12
_______________________
Bureau of Energy Efficiency
Paper-1 Set A Key
Date: 23.05.2009 Timings: 0930-1230 HRS Duration: 3 HRS Max. Marks: 150
General instructions:
o Please check that this question paper contains 7 printed pages
o Please check that this question paper contains 64 questions
o The question paper is divided into three sections
o All questions in all three sections are compulsory
o All parts of a question should be answered at one place
a) 0.1 b) 2 c) 0.4 d) 4
2. The average operating Station Heat Rate (SHR) of a Thermal Power Plants is 3000
kCal/kWh; corresponding to this the station thermal efficiency in percentage is
1
_____________________
Bureau of Energy Efficiency
Paper-1 Set A Key
2
_____________________
Bureau of Energy Efficiency
Paper-1 Set A Key
17. Which of the following will not motivate employees to conserve energy?
a) 20 b) 28 c) 30 d) 40
21. The force field analysis in energy action planning considers
3
_____________________
Bureau of Energy Efficiency
Paper-1 Set A Key
a) performance contract
b) traditional contract
c) extended technical guarantee contract
d) guaranteed savings performance contract
32. The annual electricity bill for a plant is Rs 10 lakhs and accounts for 38% of the total
energy bill. Furthermore the total energy bill increases by 5% each year. How high is the
plant’s annual energy bill at the end of the third year?
a) 70 b) 631 c) 63 d) 570
38. Which of these is not a duty of an energy manager
a) Report to BEE
b) Provide support to accredited energy auditing firm
c) Prepare a scheme for efficient use of energy
d) Sign an energy policy
39. Large scattering on production versus energy consumption trend line indicates
4
_____________________
Bureau of Energy Efficiency
Paper-1 Set A Key
a) 1 b) 21 c) 270 d) 100
48. The national inventory of greenhouse gases in India indicates that about __ % of the total
CO2 emissions come from energy sector
5
_____________________
Bureau of Energy Efficiency
Paper-1 Set A Key
S-1 What is a Sankey diagram and what are its uses ? Explain with an example.
ANS The Sankey diagram is a very useful tool to proportionally represent an entire input
and output energy flow in any energy equipment or system such as boilers, fired heaters,
furnaces etc. after carrying out an energy balance calculation, This diagram represents
visually various outputs and losses so that energy managers can focus on finding
improvements in prioritized manner.
Example:
S-2 Calculate the net present value over a period of 3 years for a project with the
following data. The discount rate is 15%.
3 75,000
S-3 In a compressed air Dryer, electrical heater is used for regeneration of silica gel.
The present Electrical energy consumption is 100 kWh/day. The management
intends to replace the electrical heater by steam coil.
a) How much steam is need per day?
b) Calculate cost savings/year. Cost of power is Rs.4/kWh and cost of steam is
Rs. 500/ton (Assuming only latent heat of steam used. Latent heat of steam is
540 kCal/kg. Efficiency of steam heating is 70%, operating days = 300)
S-4 Renovation and Modernization (R&M) of a 210 MW coal fired thermal power plant
was carried out to enhance the operating efficiency from 28% to 32%. The specific
coal consumption was 0.7 kg/kWh before R&M. For 8000 hours of operation per
year, and assuming the coal quality remains the same, calculate
a) the coal savings per year and
b) the expected avoidance of CO2 into the atmosphere in Tons/year if the
emission factor is 1.53 kg CO2/kg coal
7
_____________________
Bureau of Energy Efficiency
Paper-1 Set A Key
S-5 Explain Time of Day (TOD) Tariff and how it is beneficial for the power system
and consumers?
ANS i. In Time of the Day Tariff (TOD) structure incentives for power drawl
during off-peak hours and disincentives for power drawl during peak
hours are built in.
ii. Many electrical utilities like to have flat demand curve to achieve high
plant efficiency.
iii. ToD tariff encourage user to draw more power during off-peak hours
(say during 11pm to 5 am, night time) and less power during peak
hours. Energy meter will record peak and off-peak consumption and
normal period separately.
iv. TOD tariff gives opportunity for the user to reduce their billing, as off
peak hour tariff is quite low in comparison to peak hour tariff.
v. This also helps the power system to minimize in line congestion, in
turn higher line losses and peak load incident and utilities power
procurement charges by reduced demand
S-6 An energy meter connected to a 3 phase, 18.75 kW pump shows 108 units
consumption for six hours of operation. The load on the motor was steady. The
consumer doubted the energy meter reading and electrical parameter such as
current, voltage and power factor were measured. The measured values were
430 V line volts, 25 amps line current and 0.80 Power Factor. Find out if the
energy meter reading is correct.
S-7 What are the three flexible mechanisms available under Kyoto protocol for
achieving GHG reduction targets. Explain briefly the mechanism applicable to
India.
8
_____________________
Bureau of Energy Efficiency
Paper-1 Set A Key
The energy use of facilities varies greatly, partly due to factors beyond the energy
efficiency of the equipment and operations. These factors may include weather or certain
operating characteristics. Normalizing is the process of removing the impact of various
factors on energy use so that energy performance of facilities and operations can be
compared.
a) Benchmarking
Comparison of energy performance to peers and competitors to establish a relative
understanding of where our performance ranks.
L-2 Energy saving measures was implemented in a process plant prior to Jan-2008.
Use CUSUM technique and calculate energy savings for 6 months period of 2008.
The company produced consistently 3000 T/month in each of the six months.
9
_____________________
Bureau of Energy Efficiency
Paper-1 Set A Key
300
290 290
Consumption,kWh/MT
280 280
Specific Energy
270
260
250
240
240 239
236 235
230
220
210
200
Jan Feb Mar Apr May Jun
Month
ANS
= 40 kWh/MT x 3000 MT
Energy Savings for six months = 1.20 lakh kWh
L-3 Production rate from a paper machine is 340 tonnes per day (TPD). Inlet and outlet
dryness to paper machine is 50% and 95% respectively. Evaporated moisture
temperature is 80 °C. To evaporate moisture, the steam is supplied at 3.5 kg /cm 2.
Latent heat of steam at 3.5 kg /cm2 is 513 kCal/kg. Assume 24 hours/day operation.
i) Estimate the quantity of moisture to be evaporated.
10
_____________________
Bureau of Energy Efficiency
Paper-1 Set A Key
Latent Heat available in supply steam (at 3.5 kg/cm2 (g)) = 513 kCal/kg
L-4 a) Draw PERT Chart for the following for the task, duration and dependency given
below.
b) Find out:
i. Critical Path
ii. expected project duration
Task Predecessors
Tasks
(Dependencies) Time (Weeks)
A - 3
B - 5
11
_____________________
Bureau of Energy Efficiency
Paper-1 Set A Key
C - 7
D A 8
E B 5
F C 5
G E 4
H F 5
I D 6
J G-H 4
ANS
L-5 a) Draw an energy balance for the DG set with following data.
A Diesel Generator trial gives Set 3.5 kWh per Liter of diesel. The cooling water
loss and exhaust flue gas loss as percentage of fuel input are 28% and 32%
respectively. Assume calorific value of diesel as 10200 kCal/kg. The Specific
gravity of Diesel is 0.85. Calculate unaccounted loss as percentage of input
energy.
b) Explain the following terms in heat transfer with examples.
i) Conduction ii) Convection
b)
i) Conduction
The conduction of heat takes place, when two bodies are in contact with one
12
_____________________
Bureau of Energy Efficiency
Paper-1 Set A Key
another. If one body is at a higher temperature than the other, the motion of the
molecules in the hotter body will vibrate the molecules at the point of contact in the
cooler body and consequently result in increase in temperature.
ii) Convection The transfer of heat by convection involves the movement of a fluid
such as a gas or liquid from the hot to the cold portion. There are two types of
convection: natural and forced. In case of natural convection, the fluid in contact
with or adjacent to a high temperature body is heated by conduction. As it is
heated, it expands, becomes less dense and consequently rises. This begins a fluid
motion process in which a circulating current of fluid moves past the heated body,
continuously transferring heat away from it. In the case of forced convection, the
movement of the fluid is forced by a fan, pump or other external means. A
centralized hot air heating system is a good example of forced convection.
ESCOs are usually companies that provide a complete energy project service, from
assessment to design to construction or installation, along with engineering and
project management services, and financing.
In performance contracting, an end-user (such as an industry, institution, or utility),
seeking to improve its energy efficiency, contracts with ESCO for energy efficiency
services and financing. An agreed portion of the savings is shared with the ESCO.
The ESCO gets back the invested money plus profit over a period of time
b)
Micro factors
13
_____________________
Bureau of Energy Efficiency
Paper-1 Set A Key
Macro factors Macro economic variables are the variable that affects the operation
of the industry of which the firm operates. They cannot be changed by the firm’s
management. Macro economic variables, which affect projects, include among
others:
• Changes in interest rates
• Changes in the tax rates
• Changes in the accounting standards e.g. methods of calculating depreciation
• Changes in depreciation rates
• Extension of various government subsidized projects e.g. rural electrification
• General employment trends e.g. if the government changes the salary scales
• Imposition of regulations on environmental and safety issues in the industry
• Energy Price change
• Technology changes
14
_____________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
Date: 15.09.2012 Timings: 09:30-12:30 Hrs Duration: 3 Hrs Max. Marks: 150
1. The primary energy content of fuels is generally expressed in terms of ton of oil equivalent
(toe) and is based on the following conversion factor
a) oil and natural gas b) coal and oil c) oil and nuclear d) coal and nuclear
3. 1 kg of wood contains 15% moisture and 7% hydrogen by weight. How much water is
evaporated from wood during complete combustion of 1 kg of wood ?
d) R/P ratio varies every year with changes in both production and reserves
6.
From rated V, A and PF given in the name-plate of a motor , one can calculate:
a) rated input Power b) rated output Power c) both a & b d) none of
these
7.
Air velocity in the ducts can be measured by using ___________ and manometer
a) orifice meter b) Bourden gauge c) Pitot tube d) anemometer
________________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
i) ECBC defines the norms of energy requirements per sq. metre of area taking into
account climatic region where building is located
ii) ECBC does not encourage retrofit of Energy conservation measures
iii) ECBC prescribes energy efficiency standards for design and construction of
commercial and industrial buildings
iv) One of the key objectives of ECBC is to minimize life cycle costs (construction and
operating energy costs)
17. Which of the following statements regarding BLY (Bachat Lamp Yojana) are correct ?
i) BLY aims at large scale replacement of all fluorescent lamps of poor lumen intensity
with CFL of high lumen intensity
ii) CDM is used as a tool to recover market price difference between lower cost replaced
incandescent lamps of 60 W and higher cost CFLs of 11 W
iii) BLY involves public, private partnership and DISCOM partnerships
iv) DSM is used as a tool to recover market price difference between lower cost replaced
incandescent lamps of 60 W and higher cost CFLs of 11 W
18. The average gross efficiency of thermal power generation on all India bases is about
19. Which of the following is not the activity related to restructured APDRP?
20. Assuming total conversion of electrical energy to heat energy, how much heat is produced
by a 200 W heater in 5 minutes?
a) 200 kJ b) 40 kJ c) 1000 kJ d) 60 kJ
21. Which of the following statements regarding DSM is incorrect?
a) potential areas for DSM thrust activity are agriculture, domestic and municipalities
b) savings accrued through DSM can be treated as new power addition on supply side
c) under DSM, demand can be shifted from off-peak to peak hours thereby avoiding
imported power during off peak hours
d) DSM programs may result in demand as well as energy reduction
________________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
22. A motor with 10 kW rating in its name plate, will draw Input power of____
23. Which of the following statements is not true regarding Maximum Demand Control?
a) Maximum demand control offers a way of ‘shaving’ the peaks and ‘filling’ the valleys in
the consumer load diagram
b) Maximum demand control is carried out by concerned utility at customer
premises
c) Maximum demand control focuses on critical load for management
d) All of the above
a) reactive current is necessary to build up the flux for the magnetic field of inductive
devices
b) some portion of reactive current is converted into useful work
c) Cosine of the angle between kVA and kW vector is called power factor
d) power factor is unity in a pure resistive circuit
26. Consider two competitive projects A and B each entailing investment of Rs.85,000/- .
Project A returns Rs.50,000 at the end of each year, but Project B returns Rs.115,000 at
the end of Year 2. Which project is superior?
a) project A since it starts earning by end of first year itself and recovers cost before end
of two years
b) project B since it offers higher return before end of two years
c) both projects are equal in rank
d) insufficient information to assess the superiority
27. Which of the following statements regarding Internal Rate of Return (IRR) is correct?
________________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
30. The process of capturing CO2 from point sources and storing them is called
____________
a) wind power does not vary as the cross-sectional area of the rotor
b) wind power varies as cube of wind velocity
c) cut-in wind speed is always less than rated wind speed
d) theoretical maximum amount of energy in the wind that can be collected by wind turbine
rotor is about 95%
32. What percentage of the sun’s energy falling on a silicon solar panel gets converted into
electricity?
a) 5% b) 2% c) 0.5 % d) 3%
36. In a contract when all or part of the savings are guaranteed by contractor, and all or part of
the costs of equipment and/or services are paid out of savings as they are achieved, is
termed as
________________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
38.
If 3350 kJ of heat is supplied to 20 kg of ice at 0o C, how many kg of ice will melt into
water at 0o C (latent heat of melting of ice is 335 kJ/kg)
a) 1 kg b) 4.18 kg c) 10 kg d) 29
kg
39.
If oxygen rich combustion air (25% vol oxygen) is supplied to a furnace instead of normal
air (21% vol oxygen), the % CO2 in flue gases will
a) reduce b) increase c) remain same d) will become zero
40.
The return on investment (ROI), is expressed as
a) annual cost / capital cost b) (first cost / first year benefits) x 100
c) NPV / IRR d) (annual net cash flow x 100) /
capital cost
41.
The time between its earliest and latest start time, or between its earliest and latest finish
time of an activity is
a) delay time b) slack time c) critical path d) start time
43.
The empirical relationship used to plot Production Vs Energy consumption is………………
( where Y= energy consumed for the period; C = fixed energy consumption; M = energy
consumption directly related to production; X= production for same period).
44.
The main constituent of greenhouse gases (GHG) in atmosphere is
________________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
a) 1 b) 23 c) 300 d) 5700
46. In project management, the critical path in the network is
47. The cost of a new heat exchanger is Rs. 1.0 lakh. The simple payback period in years
considering annual savings of Rs 60,000 and annual operating cost of Rs. 10,000 is
ANS BLY aims at the large scale replacement of inefficient incandescent bulbs in
households by Compact Fluorescent Lamps (CFLs).
________________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
Briefly explain ‘Renewable Purchase Obligation (RPO)’ and means by which this
S-2
requirement can be met ?
ANS RPO is Renewable Purchase Obligation requires each retail seller of electricity to
include in its resource portfolio a certain proportion of power is from renewable
sources such as wind, solar, small hydro or various forms of biomass energy.
The retailer can meet this requirement by owning a renewable energy facility and
producing power or purchasing power from another renewable energy facility.
In the management of financial aspects, state what are micro and macro factors and
S-5
list three factors in each, which influence sensitivity analysis?
________________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
ANS
Micro factors are variables related to the project being implemented and can be
influenced
Macro factors are variables that affect the operation of industry of which the
company operates and cannot be changed by the company management.
ANS
Useful energy to generate steam by 6 tonnes of coal per day
= 6000 x 3300 x 0.72 = 14256000 kcal/day
________________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
Based on local pollution control department norms the maximum limit of dust in the
S-7
gas stream leaving the industry should not exceed one ton per day. A bag filter was
installed to reduce the pollution from the exhaust gas stream. Find out the dust
collected in ton per day if the gas stream to the dust collector was entering at the rate
of 130,000 m3 per hour containing 6 g/m3 and leaving at the rate of 150,000 m3 per
hour, inclusive of ingress of air) containing 300 mg/m3. Also find out whether, the
industry met the pollution norms if the plant operates for 24 hours a day at same
capacity.
ANS
Amount of Dust in the inlet stream = 130,000 x 6
= 780,000 grams/hour
= 17.64 Tonnes/day
Since it is more than 1 tonne/ day, the industry does not meet the pollution norms
In an industry the existing winding of a motor has burnt out. Calculate the annual
S-8
energy savings and simple payback for replacing the burnt out motor with an energy
efficient motor of the same capacity instead of rewinding.
________________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
=Rs 64055
L-1 An oil fired reheating furnace heats steel billets from 40oC to 1220oC at a furnace efficiency of
28%. The furnace operates for 4700 hours per annum. The GCV of furnace oil is10,000 kCal
/kg and density is 0.94kg/litre. The cost of furnace oil is Rs.45 /liter. The specific heat of billets
is 0.12 kCal/kgoC.
a. Calculate the amount of energy necessary to heat 12 tons
of steel billets per hour
b. Calculate liters of furnace oil fired per tons of steel billets.
c. If the efficiency of the furnace is improved from 28% to
30% by adopting ceramic fibre insulation, calculate the hourly furnace oil cost
saving
d. What is the simple payback period if the investment is Rs.
20 lakhs ?
e. How large could be the investment to improve the
efficiency at an internal rate of 16% and per year over 6 years.
ANS : a) Amount of energy necessary to heat 12 tons of steel billets
= m x cp x t
= 12000 Kgs x 0.12 x (1220- 40) kCals/hr
= 16,99,200 Kcals/hr
________________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
L-2 The Energy- production data (for Jan-June, 2011) of an industry follows a relationship :
Calculated energy consumption = 0.5 P +220.
A Waste heat recovery system was installed at end of June 2011 and further data was
gathered up to December 2011.
Using CUSUM technique, calculate energy savings in terms of ton of oil equivalent (toe) and
the reduction in specific energy consumption achieved with the installation of waste heat
recovery system.
The plant data is given in the table below.
________________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
2011- Ecal
Month Eact. 0.5P+220 Eact - Ecal CUSUM
July 590 600 -10 -10
Aug 605 630 -25 -35
Sept 670 690 -20 -55
Oct. 582 595 -13 -68
Nov. 512 525 -13 -81
Dec. 540 555 -15 -96
Energy savings achieved = 96 toe
Calculate IRR of the project by interpolation method by taking initial discount rate as 11%.
ANS a) NPV at 11% = -500000 + 120000/(1+0.11)1 + 115500/(1+0.11)2 +130000/(1+0.11)3 +
116500/(1+0.11)4 +117250/(1+0.11)5 +200000/(1+0.11)6
= 50157.88
________________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
IL = 11%
NPVL = 50157.88
IU= 16%
NPVU = -25176.29
Standards and Labeling would ensure that only energy efficient equipment and appliances
would be made available to consumers.
Main provisions of S&L are:
• Evolve minimum energy consumption and performance standards for notified equipment
and appliances
• Prevent manufacture, sale and import of equipment which do not meet the standards
• Introduce a mandatory labeling scheme for notified equipment and appliances to enable
consumers to make informed choices
• Spread information on benefits to consumers
For establishing standards, agreed testing procedures are defined and values of energy
performance are measured.
________________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
Energy labels are the best way to implement the standards. They are information affixed to
manufactured products to describe the product’s energy performance usually in form of
energy use or efficiency. These give data to consumers to make informed purchases.
b) Role of ESCOs
Conduct of Investment grade energy audit
Arranging finance
Purchase, installation and maintenance of installed energy efficient equipment
Operation & Maintenance training
Monitoring of operations and energy savings
Sun rays penetrate the outer clear glass and heat energy is absorbed by the inner coated
glass. The vacuum permits the heat radiation to enter the outer tube. The absorbent coating
on the inner tube converts short wave radiation to long wave radiation thus preventing re-
radiation to atmosphere. Since conduction cannot take place in vacuum, heat loss due to
conduction back to atmosphere is also prevented. Because of this principle, more heat is
trapped compared to a flat plate collector. The heat loss in Evacuated tube collector is less
than 10% compared with 40% for a flat plate collector. Water flows in through a third,
innermost concentric feeder tube and hot water flows out in the annulus outside the feeder
tube in contact with the absorber tube surface. This type of solar collector can reach high
temperatures upto 150°C.
b) Find out the conversion efficiency of a gasifier, if 20 kg of wood (having a calorific value of
3200 kCal / kg) produces 46 m3 of producer gas having an average calorific value of 1000
kCal / Nm3.
________________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
a) Gasification of Biomass
ANS
Biomass contains Carbon, Hydrogen and Oxygen molecules. Complete combustion of
Biomass would produce Carbon Dioxide and water vapour, whereas combustion under
controlled conditions ie partial combustion produces Carbon Monoxide and Hydrogen, which
are combustible gases. The biogas produced through gasification is called as Producer Gas.
Gasification is a partial oxidation of biomass and takes place at temperature of about 1000oC.
Partial oxidation is facilitated by supplying air less than the stoichiometric requirements. The
products of combustion are gases like Carbon Monoxide, Hydrogen and traces of Methane
and non- useful products like tar & dust. The production of these gases is by reaction of water
vapour and Carbon Dioxide through a glowing layer of charcoal.
§ Feeding of Feedstock
§ Gasifier reactions where gasification takes place.
§ Cleaning of resultant gas
§ Utilization of cleaned gas
• Drying Zone
• Distillation Zone
• Pyrolysis zone
• Combustion Zone
• Reduction Zone
C + O2 = CO2
H2 + ½ O2 = H2O
C + O2 = 2CO
C + H2O = CO + H2
CO2 + H2 = CO + H2O
C +2 H2 = CH4
The Producer gas has relatively a low calorific value ranging from 1000 to 1200 kCal/Nm3. The
conversion efficiency of Gasifier is in the range of 60 – 70%. It can be used for combustion in
________________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
a reciprocating engine.
L-6 a) Construct a PERT/CPM network diagram for a project for which the data is given below
b) Compute the earliest start, earliest finish, latest start, latest finish and slack for all the
activities
c) Also compute the project duration, identify critical activities and the critical path(s)
________________________
Bureau of Energy Efficiency
Click Here & Upgrade
Expanded Features
PDF Unlimited Pages
Documents
Complete
b) Early start (ES), Early Finish (EF), Latest start (LS), Latest finish (LF)
c) Critical Paths
________________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
Date: 24.08.2013 Timings: 09:30-12:30 HRS Duration: 3 HRS Max. Marks: 150
As per Energy Conservation Act, 2001, a BEE Certified Energy Manger is required to be
appointed/designated by the
Which of the following statement is not correct regarding Demand Side Management
(DSM)?
2
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
c) under DSM, demand can be shifted from peak to off peak hours thereby avoiding
imported power during peak hours
d) DSM programs may result in demand as well as energy reduction
a) Project A since it starts earning by end of first year itself and recovers cost before end
of two years
b) Project B since it offers higher return in two years
c) both projects are equal in rank
d) insufficient information
__________ determines the project viability in response to changes in input parameters.
3
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
4
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
Which among the following has the lowest Global Warming Potential?
a) Time between its earliest start time and earliest finish time
b) Time between its latest start time and latest finish time
c) Time between latest start time and earliest finish time
d) Time between earliest finish time and latest finish time
a) nothing can be said b) actual and calculated energy consumption are the same
c) energy consumption is reduced d) specific energy consumption is going up
CO2 measurement in a Fyrite kit is based on
a) Weight basis (dry) b) Volume basis (dry)
c) Weight basis (wet) d) Volume basis (wet)
The depletion of Ozone layer is caused mainly by _________
The Energy Conservation Act,2001 requires that all designated consumers should get
energy audits conducted periodically by
5
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
Which of the following tool is made use of to assess the input, conversion efficiency,
output, losses, quantification of all material, energy and waste streams in a process or
system?
a) 25 b) 40 c) 50 d) 62.5
2000 kJ of heat is supplied to 500 kg of ice at 0 oC. If the latent heat of fusion of ice is 335
kJ/kg then the amount of ice in kg melted will be
The fixed energy consumption of a company is 2000 kWh per month. The line slope of the
energy (y) versus production (x) chart is 0.3. The energy consumed in kWh per month for
a production level of 80,000 tons/month is
S-1 The rating of a single phase electric geyser is 2000 Watts, at 230 Volt.
Calculate:
a) Rated current
b) Resistance of the geyser in Ohms
6
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
c) Actual power drawn when the measured supply voltage is 210 Volts
Answer:
a)Rated Current of the Geyser, I = P/V= 2000/230 = 8.7 Ampere
S-2 A Diesel Generator performance trial gives specific generation of 3.5 kWh per
liter of diesel. The cooling water loss and exhaust flue gas loss as percentage of
fuel input are 28% and 32% respectively. The calorific value of diesel is 10,200
kcal/kg. The specific gravity of Diesel is 0.85. Calculate unaccounted loss as
percentage of input energy.
The net present value method calculates the present value of all the yearly cash flows
(i.e. capital costs and net savings) incurred or accrued throughout the life of a project
and summates them. Costs are represented as negative value and savings as a
positive value. The higher the net present value, the more attractive the proposed
project.
The calculation procedure for determining IRR is tedious (iterative) and usually requires
a computer spreadsheet. The exact internal rate of return can be found by interpolation
or plotting the net present value on a graph. If this discount rate is greater than current
interest rate, the investment is sound.
The project is accepted if the net present value is positive and rejected if the net
present value is negative. A negative net present value indicates that the project is not
achieving the return standard and thus will cause an economic loss if implemented. A
zero NPV is value neutral.
In IRR, the criterion for selection among alternatives is to choose the investment with
the highest rate of return. The internal rate of return figure cannot distinguish between
lending and borrowing and hence a high internal rate of return need not necessarily be
a desirable feature.
Both the NPV and IRR takes into account the time value of money and it considers the
cash flow stream in entire project life.
When the same quantity of heat is added to equal masses of iron and copper
S-5
pieces, the temperature of iron piece rises by 15 OC. Calculate the rise in
temperature of copper piece, if the specific heat of iron is 470 J / kg / OC and that
of copper is 390 J / kg / oC.
Mass of Iron x Sp. Heat Iron x 15 OC = Mass of Copper x Sp. Heat Copper x
Ans
(Rise in Temp of Copper OC)
Sp. Heat Iron x 15 OC = Sp. Heat Copper x (Rise in Temp of Copper OC)
Sp. Heat of Iron = 470 J / kg / OC
Sp. Heat of Copper = 390 J / kg / OC
= 18.08 OC
8
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
Ans
a) Stroboscope : Speed (Non Contact)
b) Sling Psychrometer : Dry & Wet Bulb Temperatures
c) Fyrite : O2 or CO2 in Flue Gases
d) Tachometer : Speed (Contact type)
e) Pitot tube : Velocity pressure of moving gases
Ans
Present Power Factor : 400 / 520 = 0.77
Present Demand Charges Rs. : 520 * 150 = 78000/-
Future Demand with higher PF : 400 / 0.95 =421 kVA
Modified Demand Charges : 421 * 150 = Rs. 63150/-
Savings =78000 – 63150
= Rs. 14850/- per Month
S-8 A 100 tonnes per day capacity chlor-alkali plant produced 30,000 tonnes per
annum (TPA) of caustic soda with annual energy consumption of
90 million kWh in the reference year 2009-10. During the year 2011-
12, the annual production was 25,000 TPA, with an annual energy
consumption of 80 million kWh. Calculate the Plant Energy
Performance.
Ans
Production Factor = 25000 / 30000
= 0.833
Reference year energy equivalent = Reference year energy use x Production factor
= (-) 6.67 %
The performance in the year 2011 – 2012 is poor as compared to the reference
year
L1 A bag house is being used to remove dust from an air exhaust stream flowing at
100 m3/min. The dirty air contains 15 g/m3 of particles, while the cleaned air from
the bag house contains 0.02 g/m3. The industry's operating permit allows the
exhaust stream to contain as much as 0.9 g/m3.
For various operating reasons, the industry wishes to bypass some of the dirty air
around the bag house and blend it back into the cleaned air so that the total
exhaust stream meets the permissible limit. Assume no air leakage and negligible
change in pressure or temperature of the air throughout the process.
Draw a schematic diagram and calculate the flow rate of air through the bag
house and the mass of dust collected per day in kg.
In this problem two balances can be made, namely, flow rate of dust in g/m 3 and flow
rate of air in m3/min. Balancing of flow rate of air in m 3/min is possible because the
temperature and pressure of air remains constant in the system.
10
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
Or
Dust removed from bag house (Z) = 100m3/min. x 15 g/m3 —100m3/min. x 0.90 g/m3
=1410 g/min.
Or
11
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
a. The calorific value is the measurement of heat or energy produced, and is measured
either as gross calorific value or net calorific value.
The difference being the latent heat of condensation of the water vapour
produced during the combustion process.
Gross calorific value (GCV) assumes all vapour produced during the combustion process is
fully condensed. Net calorific value (NCV) assumes the water leaves with the combustion
products without fully being condensed.
b)
Mass of water heated = 1.20 M3 /hr
= 1.2 x 1000 / 60 = 20 kg/min
Heat required by Water = m x Cp x (t2 – t1)
= 20 kg/min x 4.187 x 103 J/kg/0C x (65-20) oC
= 3.77 x 106 J/min
Mass of Gas kg/min = 3.77 x 106 / 0.8 /(4 x 107 )
Mass 0f Gas Required = 0.1178 kg / min
= 7.068 kg / Hr
L-3 Answer any two of the following
Responsibilities:
12
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
1. Report to BEE and State level Designated Agency once a year. The information
with regard to energy consumed and action taken in the recommendation of the
accredited energy auditor, as per BEE – Format.
2. Establish an improved data recording, collection and analysis system to keep
track of energy consumption.
3. Provide support to Accredited Energy Audit Firm retained by the company for the
conduct of energy audit.
4. Provide information to BEE as demanded in the Act, and with respect to the
tasks given by the mandate, and the job description.
5. Prepare a scheme for efficient use of energy and its conservation and implement
such scheme keeping in view the economic stability of the investment in such
firm and manner as may be provided in the regulations of the Energy
Conservation Act.
13
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
The efficiency of fuel oil fired systems will be higher than rice husk fired systems.
Hence the total energy input to the systems will increase for rice husk fired systems.
Even though material handling cost, specific fuel (energy) consumption increases for
rice husk, this is a cheap locally available renewable form of energy which will bring
down the fuel cost and transport cost compared to fuel oil.
L-4 For the following tasks, durations, and predecessor relationships in the following
activity table,
14
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
Te = (To + 4 Tm + Tp)/6
= (Tp –To)/6
V = ((Tp –To)/6)2
A - B – D – E – H –I 7+9+2+10+8+2 = 38
A–C–E–H–I 7+12+10+8+2 = 39
A–C–F–G–H–I 7+12+3+2+8+2 = 34
15
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
a) Advantages of Demand Side Management (DSM) for end user and utility
b) ISO 50001 Energy Management System
c) Distinction between energy conservation and energy efficiency
ANS a) Advantages of DSM
End user:
End use demand can be shifted from peak to off peak hours thereby reducing the need
for buying expensive energy during peak hours
Helps better manage the load curve and thus reduce the demand improve the
profitability
Utility:
Energy saving through DSM is treated same as new additions in supply side
Can reduce the capital needs for power capacity expansion
Improved loading of utility power plants and hence improved efficiency and profitability
16
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A Solutions
L-6 It is proposed to install a heat recovery device in a process industry. The capital
cost of installing the device is Rs.2,00,000 and after 5 years its salvage value is
envisaged at Rs.15,000. The savings accrued by the heat recovery device are as
shown below. Determine the net present value after 5 years for a discount rate of
8%.
Year 1 2 3 4 5
Savings (Rs.) 70,000 60,000 60,000 50,000 50,000
Ans
Year Discount factor Capital Net savings Present value (Rs.)
for 8% Investment (Rs.) (Rs.)
0 1.00 -200000 -200000
1 0.926 70000 +64820
2 0.857 60000 +51420
3 0.794 60000 +47640
4 0.735 50000 +36750
5 0.681 50000 +15000 +44265
NPV=+44895
It is evident that over a 5-year life-span the net present value of the project is 44895.
17
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
Date: 23.08.2014 Timings: 09:30-12:30 HRS Duration: 3 HRS Max. Marks: 150
a) only methane b) methane and carbon dioxide c) only ethane d) none of these
4. Which of the following statements are true?
a) (ii) & (iii) b) (i) & (iii) c) (ii) & (iv) d) (ii) & (i)
1
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
2
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
a) maximum demand controller enables a way of ‘shaving’ the peaks in the consumer
load profile
b) maximum demand controller enables a way of improving the system power factor
c) enables a way for using more electrical energy at lower total cost of energy without
investment in expansion of power supply
d) maximum demand controller is installed by concerned utility at customer premises
15. Which of the following statements are true?
i) reactive current is necessary to build up the flux for the magnetic field of inductive
devices
ii) some portion of reactive current is converted into work
iii) the cosine of angle between kVA and kVAr vector is called power factor
iv) the cosine of angle between kW and kVA vector is called power factor
i) work breakdown structure are used to list the activities in the project as a first step
in CPM
ii) CPM takes into account variation in the completion time and average time is used
for any activity
iii) if the project is to finish earlier, it is necessary to focus on activities other than
critical path
iv) critical path is the longest path in the network.
3
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
20. The process of capturing CO2 from point sources and storing them is called
24. How much theoretical power you would expect to generate from a river-based mini
hydropower with flow of 20 litres/second and head of 12 metres
25. Which among the following has the highest flue gas loss on combustion due to
Hydrogen in the fuel ?
a) natural gas b) furnace oil c) coal d) light diesel oil
4
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
28. Assume CO2 equivalent emissions by the use of a 60 W incandescent lamp are of the
order of 60 g/hr. If it is replaced by a 5 W LED lamp then the equivalent CO2 emissions
will be
a) nil b) 5 g/hr
c) 12 g/hr d) 300 g/hr
29. Under the Energy Conservation Act, the designated consumer is required to get the
mandatory energy audit conducted by
a) certified energy manager b) certified energy auditor
c) accredited energy auditor d) in-house engineer
30. If the relative humidity of air is 100%, then which of the following statements is correct
a) only dew point & wet bulb temp. are same
b) only dew point & dry bulb temp. are same
c) only wet bulb & dry bulb temp. are same
d) all dew point , wet bulb & dry bulb temp. are same
31. Among which of the following fuel is the difference between the GCV and NCV
maximum?
a) coal b) furnace oil c) natural gas d) rice husk
33. Which of the following instrument is used for assessing combustion efficiency ?
a) lux Meter b) pitot tube & manometer c) ultrasonic flow meter d) fyrite
35. If 800 kcal of heat is supplied to 20 kg of ice at 0o C, how many kg of ice will melt into
water at 0oC. (Latent heat of fusion of ice is 80 kcal/kg)
a) 1 kg b) 4 kg c) 10 kg d) 20 kg
36. If feed of 100 tonnes per hour at 5% concentration is fed to a crystallizer, the product
obtained at 25% concentration is equal to ____ tonnes per hour.
a) 15 b) 20 c) 35 d) 40
5
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
38. The rate of energy transfer from a higher temperature to a lower temperature is
measured in
39. Cost of a new heat exchanger is Rs. 1.5 lakh. The simple payback period (SPP) in years
considering annual savings of Rs 60,000 and annual maintenance cost of Rs 10,000 is
a) 0.4 b) 2.5 c) 3 d) 6
42. In an industry the average electricity consumption is 5.8 lakh kwh for a given period. The
average production is 50000 tons with a specific electricity of 11 kwh/ton for the same
period. The fixed electricity consumption for the plant is
a) 58000 kWh b) 30000kWh c) 80000kWh d) none of the above
43. The cost of replacement of inefficient compressor with an energy efficient compressor in
a plant costs Rs. 8 lakhs. The net annual cash flow is Rs. 2 lakhs. The return on
investment
a) 18% b) 20% c) 15% d) none of the above
44. The amount of electricity required to heat 100 litres of water from 30oC to 70 oC through
resistance heating is
a) 0.465 kWh b) 4.65 kWh c) 465 kWh d) 2 kWh
46. A process requires 120 kg of fuel with a calorific value of 4800 kcal/kg for heating with a
system efficiency of 82 %. The loss would be
a) 576000 kcal b) 472320 kcal c) 103680 kcal d) 480000 kcal
6
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
47. The internal rate of return is the discount rate for which the NPV is
a) positive b) zero c) negative d) less than 1
a) CO, H2 and CH4 b) only CH4 c) only CO and CH4 d) only CO and H2
The time between its earliest and latest start time, or between its earliest and latest
50.
finish time of an activity is
Calculate Net Present Value over a period of 3 years for a project with an investment of
S-1
Rs 70,000 at the beginning of the first year and second investment of Rs 70,000 at the
beginning of the second year and fuel cost saving of Rs 95,000 in second and third
year. The discount rate is 14%
Ans
NPV = –70,000 – (70000/1.14) + [95000/(1.14x1.14)] + [95000/(1.14x1.14x1.14)]
= –70000 – 61404 +73099 + 64122
= –131404 +137221
= Rs 5817/-
A water pumping station fills a reservoir at a fixed rate. The head and flow rate are
S-2
constant and hence the power drawn by the pump is always same. The pump operates
at 100 m head and delivers 250 litres per second. The power consumption was
measured as 300 kW.
7
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
S-3 A conveyor delivers coal with a width of 1 m and coal bed height of 0.25 m at a speed
of 0.5 m/s. Determine coal delivery in tons per hour considering coal density of 1.1
ton/m3.
Ans Volume of coal delivered per hour = area x length travelled per second
=1 m x 0.25 m x 0.5 m/s
= 0.125 m3/s = 450 m3/hr
Coal delivery rate = 450 m3/hr x 1.1 t/m3
= 495 t/hr
S-4 In a process industry, 12,000 kg/hr water is currently being heated from 18oCto 80oC by
indirect heating of steam. An opportunity has been identified which would preheat the
inlet water to 45oC to reduce the steam required.
Estimate the reduction in steam in kg/hr considering latent heat of steam as 520 kcal/kg
in both the cases.
8
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
(b) Standards and Labeling (Page -35): There is a wide variation in energy
consumption of similar products by various manufacturers. Also information on
energy consumption is often not easily available. Standards and Labeling (S&L)
has been identified as a key activity for energy efficiency improvement. The S&L
program, when in place, would ensure that only energy efficient equipment and
appliances would be made available to the consumers.
(c) Demand Side Management (Page -36) : Demand Side Management (DSM) means
managing of the demand for power, by utilities / Distribution companies, among
some or all its customers to meet current or future needs. DSM programs result in
energy and / or demand reduction. For example, under this process, the demand
can be shifted from peak to off peak hours thereby reducing the need for buying
expensive imported power during peak hours. DSM also enables end-users to
better manage their load curve and thus improves the profitability. Potential energy
saving through DSM is treated same as new additions on the supply side in MWs.
DSM can reduce the capital needs for power capacity expansion.
b) Name five energy intensive industries having annual energy consumption of 30,000
metric tonne of oil equivalent and above, notified as designated consumers under
the EC Act 2001
9
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
Ans a) The CO2 emitted by combustion of biomass fuels is largely balanced by the
absorption/capture of carbon dioxide during its growth.
b)
1. Thermal Power Stations
2. Fertilizer
3. Cement
4. Iron & Steel
5. Pulp & Paper
S7 Briefly explain the difference between flat plate collector and evacuated tube collector.
10
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
A sample of coal being used in a boiler is found to contain 60% carbon and 23% ash.
S8
The refuse obtained after combustion is analysed and found to contain 7% carbon &
the rest is ash.
Compute the percentage of the original carbon in coal which remains as unburnt in the
refuse.
Ans
Let the quantity of Refuse sample =100 kg
Amount of unburnt Carbon in Refuse = 7 kg
Amount of Ash in the Refuse = 93 kg
Total ash in the coal that has come into the Refuse = 23% of coal
Other data:
Annual operating hours = 3000 hours
Efficiency of indirect heating with LPG = 85%
Calorific value of LPG = 11000 kcal/kg,
Landed cost of LPG = Rs.75/kg
Cost of electricity = Rs.6/kwh.
a) If LPG is replaced with electrical heating with an investment is Rs.1.5 lakhs, compute
simple payback period.
b) Calculate the CO2 emissions in both the cases. Consider emission factors for LPG as 3
tons of CO2/Ton of LPG and Electricity as 0.81 tons of CO2/MWh
11
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
Annual CO2 emission with electrical heating 210 x 0.81 =170 t CO2
L2 A project has the following activities, precedence relationships, and time estimates in
weeks:
a) Draw the network diagram (expected time may be rounded to the nearest whole number)
b) Identify the critical path and
c) Determine the project duration.
12
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
C (31)
A (20) (20, 51)
(0, 20)
2
(24, 55)
(4, 24) G (20) 6
1 (25, 45)
B (10) (35, 55)
(0, 10) D (15) 4 F (20)
(10, 25)
(0, 10) (35, 55)
(20, 35) E (25) (35, 55)
3 (10, 35)
(10, 35) 5
b)Critical Path : B-E-F
Option A:. Investment envisaged Rs. 40 lakhs with an annual return of Rs. 8
lakhs; Life of the project is 10 years
Calculate IRR of both the options and suggest which option the company should select.
13
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
Option A:
Investment = Rs. 40 lakh
Annual Return = Rs. 8 lakh
Life of project = 10 years
0 = [(-) 40 x 105 ] + [(8 x 105) / (1 + 0.15)1] + [(8 x 105) / (1 + 0.15)2 ] + ---------- + [(8 x 105)
/ (1 + 0.15)9 ] + [ ( 8 x 105) / (1 + 0.15)10 ]
= 15.12 %
Option B:
Investment = Rs. 24 lakh
Annual Return = Rs. 5 lakh
Life of project = 8 years
0 = [(-) 24 x 105 ] + [ (5 x 105) / (1 + 0.13)1 ] + [(5 x 105) / (1 + 0.13)2] + ---------- + [(5 x 105) /
(1 + 0.13)7 ] + [ (5 x 105) / (1 + 0.13)8 ]
= 13.04 %
Based on IRR, the Option A has higher IRR value and the company may opt for Option A.
ESCOs are usually companies that provide a complete energy project service, from
assessment to design to construction or installation, along with engineering and project
management services, and financing.
For example, a lighting retrofit has a high probability of producing the expected cash flows,
whereas a completely new process does not have the same “time tested” reliability. If the
in-house energy management team cannot manage this risk, performance contracting may
be an attractive alternative.
The ESCO will usually offer the following common types of contracts:
Fixed fee
Shared savings
14
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
Guaranteed savings
Many of the cash flows in the project are based on assumptions that have an element of
uncertainty. The cash flows such as capital cost, energy cost savings, maintenance costs
can usually be estimated fairly accurately. Even though these costs can be predicted with
some certainty, it should always be remembered that they are only estimates. Cash flows in
future years normally contain inflation components and project life itself can vary
significantly.
Sensitivity analysis is undertaken to identify those parameters that are both uncertain and
for which the project decision taken through the NPV or IRR is sensitive. The effect of
switching values of key variables required for the project decision (from acceptance to
rejection) can be compared with the post evaluation results of similar projects. Sensitivity
and risk analysis should lead to improved project design, with mitigation actions against
major sources of uncertainty involved.
The various micro and macro factors / variables that are considered for the sensitivity
analysis are listed below.
Micro factors:
Operating expenses (various expenses items)
Capital structure
Costs of debt, equity
Changing of the forms of finance e.g. leasing
Changing the project life
15
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
Macro factors: Macro economic variables are the variable that affects the operation of the
industry of which the company operates. They cannot be changed by the firm’s
management. Macro economic variables, which affect projects, include among others:
The Sankey diagram is very useful tool to represent an entire input and output energy flow
in any energy equipment or system such as boiler generation, fired heaters, furnaces after
carrying out energy balance calculation. Usually the flows are represented by arrows. The
width of the arrows is proportional to the size of the actual flow. Better than numbers, tables
or descriptions, this diagram represents visually various outputs (benefits) and losses so that
energy managers can focus on finding improvements in a prioritized manner.
L5 a) Calculate the annual energy savings and simple payback from replacing standard
existing motor with energy efficient motor versus rewinding the existing motor.
b) During an air pollution monitoring study, the inlet gas stream to a bag filter was 200,000
m3 per hour. The outlet gas stream from the bag filter was little bit higher at 220,000m 3 per
hour. The dust load at the inlet was 5 g/m3 and at the outlet 0.2 g/m3.
How much dust in kg/hour was collected in the bag filter bin?
a)
a) Solution: Energy cost savings (Rs/year)
=[(KW)*(% loading)*{(100/efficiency of rewound standard motor)-(100/efficiency of energy
efficient motor)}*(Hrs/annum)*(Rs/kwh)]
= 20*0.82*7200*[(100/87)-(100/94)]*5.2
=118080*[1.1494-1.0638]*5.2
=52560/-
b) Dust (gas in) = dust (in gas out) + dust (in bin)
200000 x 5 = 220000 x 0.2 + X
X = 1000000 – 44000
= 956000 gm/hr
= 956 Kg/hr
a) 5S
b) KAIZEN
c) ISO 50001
d) TPM
5S, abbreviated from the Japanese words Seiri, Seiton, Seiso, Seiketsu, and Shitsuke,
are simple but effective methods to organize the workplace.
The 5S, translated into English are: housekeeping, workplace organization, cleanup,
maintain cleanliness, and discipline. They can be defined as follows:
Housekeeping. Separate needed items from unneeded items. Keep only what is
17
_______________________
Bureau of Energy Efficiency
Paper 1 –Set A
Implementing 5S methods in the plant would help the company to reduce waste hidden in
the plant, improve the levels of quality and safety, reduce the lead time and cost, and thus
increase Company’s profit.
KAI – Change
ZEN – Good (for the better)
KAIZEN – Change for the better or continuous improvement.
Kaizen events focuses on reducing various forms of wastes and often energy reduction
result from projects that focus on an area or a process. For example, a project that was
implemented to reduce colouring chemicals in a plastic industry resulted in small changes
in plant layout and material flow to its use. This ended up in big reduction in amount of
forklift travelled and fuel used in the forklift.
Implementation:
Step-1: Identification of a problem, i.e. waste, defect or something not working. The
operator writes and describes the problem
Step-2: Operator later develops an improvement idea and goes to immediate supervisor
Step-3: Supervisor / Kaizen team members review it and encourage immediate action and
fills up the Kaizen form
Step-4: The idea is implemented & checked.
Step-5: The operator is rewarded.
ISO 50001 will establish a framework for industrial plants, commercial facilities or entire
organizations to manage energy. The document is based on the common elements found
in all of ISO’s management system standards, assuring a high level of compatibility with
ISO 9001 (quality management) and ISO 14001 (environmental management).
energy conservation.
- Energy supply;
- Measurement;
- Documentation and reporting of energy use; and
- Procurement & design practices for energy-using equipment, systems and
processes.
To simply put it, ISO 50001 is “saying what you do and doing what you say”.
Total productive maintenance (TPM) is the method that focuses on optimizing the
effectiveness of manufacturing equipment. TPM builds upon established equipment-
management approaches and focuses on team-based maintenance that involves
employees at every level and function.
TPM addresses the entire production system lifecycle and builds a concrete, shop floor-
based system to prevent all losses. It aims to eliminate all accidents, defects, and
breakdowns.
TPM involves all departments from production to development, sales, and
administration.
Everyone participates in TPM, from the top executive to shop floor employees.
TPM achieves zero losses through overlapping team activities.
19
_______________________
Bureau of Energy Efficiency
REGULAR Paper 1 –Set A
MODEL SOLUTIONS
1
REGULAR Paper 1 –Set A
a) latent heat b) one kilojoule c) one kilo calorie d) none of the above
11. The present value of Rs. 1,000 in 10 years’ time at an interest rate of 10% is
a) 2 b) 3 c) 4 d) 5
13. The monthly electricity bill for a plant is Rs. 100 lakhs which accounts for 45%
of the total monthly energy bill. How much is the plant’s monthly energy bill
2
REGULAR Paper 1 –Set A
3
REGULAR Paper 1 –Set A
23. In an industry the average electricity consumption is 5.8 lakhs kWh for the
period, the average production is 50,000 tons with a specific electricity of 11
kWh/ton for the same period. The fixed electricity consumption for the plant
is
4
REGULAR Paper 1 –Set A
29. If heat rate of power plant is 860 kcal/kWh then the cycle efficiency of power
plant will be
5
REGULAR Paper 1 –Set A
37. Costs associated with the design, planning, installation and commissioning of
a project are
6
REGULAR Paper 1 –Set A
operate and maintain. If the annual savings is Rs. 20 lakhs, the payback
period will be
a) 47 m3 b) 48 m3 c) 50 m3 d) 53 m3
49. 100 tons of coal with a GCV of 4200 kcal/kg can be expressed in ‘tonnes of oil
equivalent’ as
a) 42 b) 50 c) 420 d) 125
50. 1 kg of wood contains 15% moisture and 7% hydrogen by weight. How much
water is evaporated during complete combustion of 1 kg of wood
7
REGULAR Paper 1 –Set A
S-1 A gas fired water heater heats water flowing at a rate of 20 litres per minute
from 250 C to 85oC. If the GCV of the gas is 9200 kcal/kg, what is the rate of
combustion of gas in kg/min (assume efficiency of water heater as 82%)
Solution:
S-2 Calculate the net present value over a period of 3 years for a project with
the following data. The discount rate is 12%.
8
REGULAR Paper 1 –Set A
Ans:
NPV = - 75,000 + 25,000/(1+0.12) + 75,000/(1+0.12)2 + (75,000 –
50,000)/(1+0.12)3
S-4 List down at least five schemes of BEE under the Energy Conservation Act –
2001
Ans:
Schemes of BEE under the Energy Conservation Act - 2001 are as
follows:
Energy conservation building codes (ECBC)
Standards and labeling (S&L)
Demand side management (DSM)
Bachat Lamp Yojana (BLY)
Promoting energy efficiency in small and medium enterprises
(SME’s)
Designated consumers
Certification of energy auditors and energy managers
9
REGULAR Paper 1 –Set A
a) Pitot tube
b) Stroboscope
c) Fyrite
d) Psychrometer
e) Anemometer
Ans:
S-6 What are ESCerts and explain the basis for their issue and trading under PAT
scheme ?
PAT scheme provides the option for industries who achieve superior
savings to receive energy savings certificates for this excess savings, and to
trade the additional certified energy savings certificates with other
designated consumers (energy intensive industries notified as
Designated Consumers under the Energy Conservation Act and included
under PAT Scheme) who can utilize these certificates to comply with
their specific energy consumption reduction targets. Energy Savings
Certificates (ESCerts) so issued will be tradable at Power Exchanges. The
scheme also allows units which gain ESCerts to bank them for the next cycle
of PAT, following the cycle in which they have been issued.
S–7 Pressure of a nitrogen gas supplied to an oil tank for purging is measured as
100 mm of water gauge when barometer reads 756 mm of mercury.
10
REGULAR Paper 1 –Set A
Using the ideal gas equation and putting the above values;
PV = nRT
101.79 x V = 0.0536 x 8.3143 x 298
V = 1.395 m3
11
REGULAR Paper 1 –Set A
12
REGULAR Paper 1 –Set A
L-1 a) A furnace heating steel ingots is fired with oil having a calorific value of 10,500
kCal/kg and efficiency of 75%. Calculate the oil consumption per hour when the
throughput of the furnace is 50 TPH and the temperature of the finished product is
600 oC. Take ambient temperature as 30 oC and Specific Heat of Steel as 0.12
kCal/kg oC
b) In Steel industry, different types of gases are generated during steel making
process.
All these gases are mixed in the gas mixer before combustion. Find out the
Calorific Value (in kCal/SM3) of mix gas.
Ans:
a) Oil Consumption / hr
= 0.43 TPH
13
REGULAR Paper 1 –Set A
b) Total flow of Mix Gas = 75,000 + 50,000 + 55,000 + 80,000 = 2,60,000 SM3/hr
CV of Mix Gas =
[(75,000 x 4,000) + (50,000 x 2,000) + (55,000 x 1,500) + (80,000 x 700)] /
2,60,000
= 2,071 kCal/SM3
L–2 A) Briefly explain the following terms with respect to energy management?
I. Normalizing
II. Benchmarking
Ans:
A) I) Normalizing:
The energy use of facilities varies greatly, partly due to factors beyond the energy
efficiency of the equipment and operations. These factors may include weather or
certain operating characteristics. Normalizing is the process of removing the
impact of various factors on energy use so that energy performance of facilities
and operations can be compared.
II) Benchmarking:
14
REGULAR Paper 1 –Set A
Substituting existing fossil fuels/energy with more efficient and / or less cost/less
polluting fuel.
L-3 The details of activities for a pump replacement project is given below:
15
REGULAR Paper 1 –Set A
Duration = 28 days
The steam is supplied at 4 kg/cm2, having a latent heat of 510 kCal/kg. The
evaporated moisture temperature is around 100 0C having enthalpy of 640
kCal/kg. Plant operates 24 hours per day. Assume only latent heat of steam is
being used for drying the paper and neglect the enthalpy of the moisture
in the wet paper.
Ans:
Output of the drying machine = 480 TPD with 95% dryness.
Bone dry mass of paper at the output = 480 x 0.95 = 456 TPD
16
REGULAR Paper 1 –Set A
L-5 Use CUSUM technique to develop a table and to calculate energy savings for 8
months period. For calculating total energy saving, average production can be
taken as 6,000 MT per month. Refer to field data given in the table below.
17
REGULAR Paper 1 –Set A
Ans
Solution:
1) In Time of the Day Tariff (TOD) structure incentives for power drawl during
off-peak hours and disincentives for power drawl during peak hours are built
in.
Many electrical utilities like to have flat demand curve to achieve high
plant efficiency.
ToD tariff encourage user to draw more power during off-peak hours
18
REGULAR Paper 1 –Set A
(say during 11pm to 5 am, night time) and less power during peak hours.
Energy meter will record peak and off-peak consumption and normal
period separately.
ToD tariff gives opportunity for the user to reduce their billing, as off
peak hour tariff is quite low in comparison to peak hour tariff.
This also helps the power system to minimize in line congestion, in turn
higher line losses and peak load incident and utilities power
procurement charges by reduced demand
19
REGULAR Paper 1 –Set A
behaviours
20
Paper 1 –Set A Reg with Solutions
General instructions:
o Please check that this question paper contains 8 printed pages
o Please check that this question paper contains 64 questions
o The question paper is divided into three sections
o All questions in all three sections are compulsory
o All parts of a question should be answered at one place
1. The energy intensity of countries that rely on import of carbon-intensive goods when
compared with those producing it, would in all probability be
i) ECBC defines the norms of energy requirements per cubic metre of area
ii) ECBC does not encourage retrofit of Energy conservation measures
iii) ECBC prescribes energy efficiency standards for design and construction of
commercial and industrial buildings
iv) One of the key objectives of ECBC is to minimize life cycle costs
(construction and operating energy costs)
a) i b) ii c) iiii d) iv
4. Verification and Check-verification under PAT will be carried out by
a) Designated consumers
b) Accredited energy auditors
c) Certified energy auditor
d) Empanelled accredited energy auditors
a) Light pipes
_______________________ 1
Bureau of Energy Efficiency
Paper 1 –Set A Reg with Solutions
a) Chlor-alkali c) Cement
b) Aluminum d) Commercial buildings
_______________________ 2
Bureau of Energy Efficiency
Paper 1 –Set A Reg with Solutions
a) Satisfies regulations
b) Reflects top management commitment
c) Indicates availability of energy audit skills
d) None of the Above
16. Red wood seconds is a measure of
a. Electrical energy
b. Thermal energy
c. Kinetic energy
d. Potential energy
21. For every 10°C rise in temperature, the rate of chemical reaction doubles. When the
temperature is increased from 30°C to 70°C, the rate of reaction increases __________
times.
a) 8 b) 64 c) 16 d) none of the above
22. The producer gas is basically
_______________________ 3
Bureau of Energy Efficiency
Paper 1 –Set A Reg with Solutions
26. If the reactive power drawn by a particular load is zero it means the load is operating
at
a) Lagging power factor b) Unity power factor
c) Leading power factor d) none of the above
a) Design of Project
b) Installation and Commissioning of Project
c) Operation and Maintenance cost of project
d) both a and b
28. Any management would like to invest in projects with
a. Positive
b. Zero
c. Negative
d. Less than 1
32. Greenhouse effect is caused by natural affects and anthropogenic effects. If there is no
natural greenhouse effect, the Earth's average surface temperature would be around
__________°C.
a) 0 b) 32 c) 14 d) - 18
o
33. The quantity of heat required to raise the temperature of a given substance by 1 C is
known as:
a) 40 b) 50 c) 100 d) 125
35. A mass balance for energy conservation does not consider which of the following
a. Steam
b. water
c. Lubricating oil
d. Raw material
36. A sling psychrometer is capable of measuring
_______________________ 4
Bureau of Energy Efficiency
Paper 1 –Set A Reg with Solutions
In a coal fired boiler, hourly consumption of coal is 1300 kg. The ash content in the coal
41. is 6%. Calculate the quantity of ash formed per day. Boiler operates 24 hrs/day.
a) 216 kg b) 300 kg c) 1872 kg d) none of the above
42. Liquid fuel density is measured by an instrument called
a) Tachometer b) hygrometer c) anemometer d) none of the above
43. A comparison of the trapping of heat by CO2 and CH4 is that
a) CH4 traps 21 times more heat in the atmosphere than does CO 2
b) CO2 traps 21 times more heat in the atmosphere than does CH4
c) the same amount of heat is trapped by both CO2 and CH4
d) none of the above
44. Diagrammatic representation of input and output energy streams of an equipment or
system is known as
a) mollier diagram b) sankey diagram
c) psychrometric chart d) balance diagram
45. ISO 50001:2011 provides a framework of requirements for organizations to:
a) Develop a policy for more efficient use of energy b) Measure the results
c) Fix targets and objectives to meet the policy d) all of the above
46. A three phase induction motor is drawing 16 Ampere at 440 Volts. If the operating power
factor of the motor is 0.90 and the motor efficiency is 92%, then the mechanical shaft
power output of the motor is
a) 12.04 kW b) 10.09 kW
c) 10.97 kW d) None of the above
47. Absolute pressure is
a. Gauge pressure
b. Gauge pressure + Atmospheric pressure
c. Atmospheric pressure
d. Gauge pressure - Atmospheric pressure
48. In a chemical process two reactants A (300 kg) and B (400 kg) are used. If conversion is
50% and A and B react in equal proportions, the mass of the product formed is.
_______________________ 5
Bureau of Energy Efficiency
Paper 1 –Set A Reg with Solutions
a) 300 kg b) 350 kg
c) 400 kg d) none of the above
49. What is the expected power output in watts from a wind turbine with 6m diameter rotor,
a coefficient of performance 0.45, generator efficiency 0.8,a gear box efficiency 0.90
and wind speed of 11m/sec
a. 4875 watts
b. 1100 watts
c. 7312 watts
d. 73.12 kW
50. The lowest theoretical temperature to which water can be cooled in a cooling tower is
a. Difference between DBT and WBT of the atmospheric air
b. Average DBT and WBT of the atmospheric air
c. DBT of the atmospheric air
d. WBT of the atmospheric air
i) Pascal
2
ii) kg / cm
iii) Atmospheric
iv) mm of mercury
v) Meters of water column
2
vi) Pounds / inch
S- 2 A plant is using 6 tonnes / day of coal to generate steam . The calorific of coal is 3300
kcal/kg. The cost of coal is Rs 4200/tonne . The plant substitutes coal with agro-residue ,
as a boiler fuel, which has a calorific value of 3100 kcal/kg and costs Rs 1800/tonne.
Calculate the annual cost savings at 300 days of operation, assuming the boiler efficiency
remains same at 72% for coal and agro residue as fuel.
_______________________ 6
Bureau of Energy Efficiency
Paper 1 –Set A Reg with Solutions
ESCOs are usually companies that provide a complete energy project service, from assessment
to design to construction or installation, along with engineering and project management services
and financing.
The ESCO will usually offer the following performance contract options.
Fixed fee
Shared Savings
Guaranteed savings
S-4 The annual fuel cost of boiler operation in a plant is Rs.10 Lakhs. The boiler with 65%
efficiency is now replaced by a new one with 78% efficiency. What is the annual cost
savings?
Proposed efficiency=78%
= 10 x ((1-(0.65/0.78))
S-5 A tank containing 600 kg of kerosene is to be heated from 10°C to 40°C in 20 minutes,
using 4 bar (g) steam. The kerosene has a specific heat capacity of 2.0 kJ/kg °C over that
temperature range. Latent heat of steam (hfg) at 4.0 bar g is 2108.1 kJ/kg. The tank is well
insulated and heat losses are negligible.
Determine the steam flow rate in kg/hr.
O O
Q = 600 kg x 2 kJ/kg C x (40-10) C/(1200)
= 30 kJ/sec
= 51.23 kg/h
S–6 Feed water is provided to a boiler at 70oC from the feed water tank. The
temperature of condensate water returning to the tank is 86oC, while the
_______________________ 7
Bureau of Energy Efficiency
Paper 1 –Set A Reg with Solutions
S–8 The average monthly electricity consumption in an Aluminium producing unit is 12.35 lac
kWh. The other energy sources used in the manufacturing process are Furnace oil (GCV-
9660 kcal/Ltr) and HSD (GCV-9410 kcal/Ltr). If the annual fuel oil consumption is 5760 kL of
Furnace oil (sp. gr. 0.92) and 720 kL of HSD (sp. gr. 0.88), determine if the unit qualifies as a
Designated Consumer under the EC Act?
7
1 Mtoe = 1 x 10 kcal
Annual electrical energy consumption = 12.35 x 12 = 148.2 lac Kwh
5 7
Equivalent heat energy = (148.2 x 10 x 860)/(1 x 10 )
= 1274.52 Mtoe _(i)
Annual Furnace oil consumption = 5760 kL
7
Equivalent heat energy = (5760 x 1000 x 9660)/(1 x 10 )
= 5564.16 Mtoe _(ii)
Annual HSD consumption = 720 kL
7
Equivalent heat energy = (720 x 1000 x 9410)/(1 x 10 )
= 677.52 Mtoe _(iii)
To be a designated consumer, the minimum annual energy consumption (in aluminium sector)
_______________________ 8
Bureau of Energy Efficiency
Paper 1 –Set A Reg with Solutions
should be 7500 Mtoe. As the plant exceeds this threshold limit, it qualifies to be a designated
consumer.
_______________________ 9
Bureau of Energy Efficiency
Paper 1 –Set A Reg with Solutions
L-1 The integrated paper plant has produced 119366 MT of paper during the year 2012-13. The
management has implemented various energy conservation measures as part of PAT scheme
and reduced the specific energy consumption from 53 GJ/ tonne of product to 50 GJ/tonne of
product. The actual production during the assessment year (2014-15) is 124141 MT. Calculate
the plant energy performance and state your inference.
= 53 x 119366 = 6326398 GJ
Inference : plant energy performance is positive and hence the plant is achieving energy savings.
L – 2 a) A 20 kW, 415V, 38A, 4 pole, 50 Hz, 3 phase rated squirrel cage induction motor has a full
load
efficiency and power factor of 88% and 0.85 respectively. An energy auditor measures the
_______________________ 10
Bureau of Energy Efficiency
Paper 1 –Set A Reg with Solutions
following
operating data of the motor.
1) Supply voltage= 408V
2) Current drawn= 30A
3) PF=0.83
Find out the following at motor operating conditions.
1) Power input in kW
2) % motor loading
b)
Replacement of inefficient electric lamps with efficient electric lamps
Using star labeled household appliances like A/c’s, Refrigerator,Lamps,Fans
Using Solar water heating systems for hot water requirements to minimize use of electric
geysers
Using Solar PV systems for electricity generation
Proper ventilation maximizing the use of natural light
Switching off all equipment when not required
Using pressure cooker for cooking food
Maximizing the use of low fire burner (SIM) in the gas stove
o o o
Using A/Cs at setpoint of 21 C-23 C instead of 16 C
Placing the fridge so that the rear ( condenser coils ) are located where there is proper air
flow.
L-3 The cash flows in two different energy conservation projects are given in the table below. Please help
the management of an infrastructure company to decide which project to invest in as the
management is interested in investing in only one project. The company is likely to consider any
project which gives a minimum return on investment of 18%. Please justify your choice.
(Amount in Rs.)
Project A Project B
Investment 17,50,000/- 12,00,000/-
Year Expenses Savings Expenses Savings
1 4,00,000 4,50,000
2 4,00,000 4,00,000
3 4,00,000 3,50,000
4 4,00,000 3,00,000
5 1,00,000 6,00,000 2,50,000
6 6,00,000 2,00,000
7 6,00,000 1,16,650
_______________________ 11
Bureau of Energy Efficiency
Paper 1 –Set A Reg with Solutions
8 3,80,300
Ans As the investments required in both the cases as well as their durations are different, the prudent
method to compare the two projects would be to calculate their NPV.
0 1
a) NPV of Project A @ 18% = (-1750000 / (1+0.18) ) + (4,00,000 / (1+0.18) ) +(4,00,000 /
2 3 4 5
(1+0.18) ) +(4,00,000 / (1+0.18) )+ (4,00,000 / (1+0.18) ) +((6,00,000-100000) / (1+0.18) )+
6 7 8
(6,00,000 / (1+0.18) ) +(6,00,000 / (1+0.18) )+ (3,80,300 / (1+0.18) ) = 57,367
0 1
b) NPV of Project B @ 18% = (-1200000 / (1+0.18) ) + (4,50,000 / (1+0.18) ) +(4,00,000 /
2 3 4 5
(1+0.18) ) +(3,50,000 / (1+0.18) )+ (3,00,000 / (1+0.18) ) +(2,50,000 / (1+0.18) )+ (2,00,000 /
6 7
(1+0.18) ) +(1,16,650 / (1+0.18) ) = 57370
Since both the projects are having the same NPV at 18%, both the projects are worth
considering. However, by increasing the rate 20% if one of the projects shows higher NPV, that
project would be the choice between the two.
0 1 2
c) NPV of Project A @ 20% = (-1750000 / (1+0.2) ) + (4,00,000 / (1+0.2) ) +(4,00,000 / (1+0.2) )
3 4 5
+(4,00,000 / (1+0.2) )+ (4,00,000 / (1+0.2) ) +((6,00,000-100000) / (1+0.2) )+ (6,00,000 /
6 7 8
(1+0.2) ) +(6,00,000 / (1+0.2) )+ (3,80,300 / (1+0.2) ) = (-) 56734
0 1 2
d) NPV of Project B @ 20% =(-1200000 / (1+0.2) ) + (4,50,000 / (1+0.2) ) +(4,00,000 / (1+0.2) )
3 4 5 6
+(3,50,000 / (1+0.2) )+ (3,00,000 / (1+0.2) ) +(2,50,000 / (1+0.2) )+ (2,00,000 / (1+0.2) )
7
+(1,16,650 / (1+0.2) ) = 3.86
As the NPV of project B at 20% is higher than that of Project A, Project B is recommended.
L – 4 The energy consumption pattern in a steel re rolling mill over 8 month period is provided in the table
below;
Month Production (Tons) Coal Consumption (Tons)
1 488 422
2 553 412
3 455 411
4 325 363
5 488 438
6 585 426
7 455 414
8 419 396
Estimate,
_______________________ 12
Bureau of Energy Efficiency
Paper 1 –Set A Reg with Solutions
Ans To establish the relationship between Production & Coal consumption, it is necessary to derive the
best-fit line for which the following normal equation are used ( see page 218 of book 1)
Cn +m∑x =∑y
2
c∑x + m∑x =∑xy
2
n x y x xy
1 488 422 238144 205936
2 553 412 305809 227836
3 455 411 207025 187005
4 325 363 105625 117975
5 488 438 238144 213744
6 585 426 342225 2 9 10
7 455 414 20702 188370
8 419 396 175561 165924
Total 3768 3282 1819558 1556000
c = (3282 -3768m) / 8
m = 0.23 and
c = 316
y = 0.23x + 316
Ans Perform, Achieve and Trade (PAT) Scheme is a market based mechanism to enhance cost
effectiveness of improvements in energy efficiency in energy-intensive large industries and
facilities, through certification of energy savings that could be traded.
_______________________ 13
Bureau of Energy Efficiency
Paper 1 –Set A Reg with Solutions
The key goal of PAT scheme is to mandate specific energy efficiency improvements for the most
energy intensive industries. The scheme builds on the large variation in energy intensities of
different units in almost every sector. The scheme envisages improvements in the energy intensity
of each unit covered by it. The energy intensity reduction target mandated for each unit is dependent
on its operating efficiency: the specific energy consumption reduction target is less for those who are
more efficient, and is higher for the less-efficient units.
Further, the scheme incentivizes units to exceed their specified SEC improvement targets. To
facilitate this, the scheme provides the option for industries who achieve superior savings to receive
energy savings certificates for this excess savings, and to trade the additional certified energy
savings certificates with other designated consumers(energy intensive industries notified as
Designated Consumers under the Energy Conservation Act and included under PAT Scheme)
who can utilize these certificates to comply with their specific energy consumption reduction targets.
Energy Savings Certificates (ESCerts) so issued will be tradable at Power Exchanges. The scheme
also allows units which gain ESCerts to bank them for the next cycle of PAT, following the cycle in
which they have been issued. The number of ESCerts which would be issued would depend on the
quantum of energy saved over and above the target energy savings in the assessment year (for
st
1 Cycle of PAT, assessment year is 2014-15).
After completion of baseline audits, targets varying from unit to unit ranging from about 3 to 7% have
been set and need to be accomplished by 2014-15 and after which new cycle with new targets will be
proposed. Failing to achieve the specific energy consumption targets in the time frame would attract
penalty for the non-compliance under Section 26 (1A) of the Energy Conservation Act, 2001
(amended in 2010). For ensuring the compliance with the set targets, system of verification and
check-verification will be carried out by empanelment criteria of accredited energy auditors.
Let
F indicate quantity of feed
_______________________ 14
Bureau of Energy Efficiency
Paper 1 –Set A Reg with Solutions
_______________________ 15
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
Date: 23.09.2017 Timings: 0930-1230 HRS Duration: 3 HRS Max. Marks: 150
General instructions:
o Please check that this question paper contains 11 printed pages
o Please check that this question paper contains 64 questions
o The question paper is divided into three sections
o All questions in all three sections are compulsory
o All parts of a question should be answered at one place
a) energy conservation
b) energy efficiency
c) both energy conservation and energy efficiency
d) carbon neutrality
4. A building intended to be used for commercial purpose will be required to follow
Energy conservation building code under Energy Conservation Act, 2001 provided its
_______________________ 1
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
i) reactive current is necessary to build up the flux for the magnetic field of
inductive devices
ii) some portion of reactive current is converted into work
iii) the cosine of angle between kVA and kVAr vector is called power factor
iv) the cosine of angle between kW and kVA vector is called power factor
_______________________ 2
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
10. Which among the following has the highest flue gas loss on combustion due
to Hydrogen in the fuel?
_______________________ 3
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
is Rs 0.5 lakh. The maintenance cost is Rs. 5,000/year. The return on investment is
22. The power generation potential in mini hydro power plant for a water flow of 3 m3/sec
with a head of 14 meters and with a system efficiency of 55% is
23. Which of the following two statements are true regarding application of Kaizen for
energy conservation?
a) Time between its earliest start time and earliest finish time
b) Time between its latest start time and latest finish time
c) Time between latest start time and earliest finish time
d) Time between earliest finish time and latest finish time
27. The Energy Conservation Act,2001 requires that all designated consumers should get
energy audits conducted periodically by
_______________________ 4
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
a) 2 b) 3 c) 4 d) 5
37. In a manufacturing plant, following data are gathered for a given month: Production -
1200 pieces; specific energy consumption - 1000 kWh/piece; variable energy
consumption - 950 kWh/piece. The fixed energy consumption of the plant for the month
_______________________ 5
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
is -------
a) CO2 b) CFC
c) Sulfur Hexafluoride (SF6) d) perfluorocarbon (PFC)
39. The component of electric power which yields useful mechanical power output is known
as
a) 12.04 kW b) 10.09 kW
c) 10.97 kW d) None of the above
42. The energy conversion efficiency of a solar cell does not depend on
_______________________ 6
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
d) the molecules of low grade energy are more randomly distributed than the molecules
of carbon in coal
46. Which of the following is not applicable to liquid fuels?
S-1 Explain Time of Day (TOD) Tariff and how it is beneficial for the power system and
consumers?
Ans In Time of the Day Tariff (TOD) structure incentives for power drawl during off-
peak hours and disincentives for power drawl during peak hours are built in. Many
_______________________ 7
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
electrical utilities like to have flat demand curve to achieve high plant efficiency.
ToD tariff encourage user to draw more power during off-peak hours (say during
11pm to 5 am, night time) and less power during peak hours. Energy meter will
record peak, off-peak and normal period consumption, separately.
TOD tariff gives opportunity for the user to reduce their billing, as off peak hour
tariff is quite low in comparison to peak hour tariff.
This also helps the power system to minimize in line congestion, in turn higher
line losses and peak load incident and utilities power procurement charges by
reduced demand
…………………..5 marks
( each point consider 1.5 marks)
S- 2 In a chemical factory where dyes are made, wet cake at 30 OC consisting of 60% moisture
is put in a dryer to obtain an output having only 5% moisture, at atmospheric pressure. In
each batch about 120 kgs of material is dried.
b. What is the total quantity ( sensible & latent) of heat required to evaporate the
moisture, if the latent heat of water is 540 kcal/kg at atmospheric conditions,
Ignore heat absorbed by the solids
c. Find the quantity of steam required for the drying process (per batch), if steam
at 4 kg/cm2 is used for generating hot air in the dryer and the dryer efficiency
is 80%. Latent heat of steam at 4 kg/cm2 is 520 kcal/kg.
_______________________ 8
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
To evaporate the moisture at atmospheric pressure, the material has to be first heated
up to 100 OC.
…………………….2 marks
Ans Perform, Achieve and Trade (PAT) Scheme is a market based mechanism to
enhance cost effectiveness of improvements in energy efficiency in energy-intensive
large industries and facilities, through certification of energy savings that could be
traded. The genesis of the PAT mechanism flows out of the provision of the
Energy Conservation Act, 2001 (amended in 2010).
The key goal of PAT scheme is to mandate specific energy efficiency improvements for
the most energy intensive industries in sectors as listed below.
Sector
1. Aluminium
2. Cement
3. Chlor-Alkali
4. Fertilizer
5. Iron and Steel
6. Pulp and Paper
7. Textile
8. Thermal Power Plant
_______________________ 9
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
The energy intensity reduction target mandated for each unit is depended on its operating
efficiency and the specific energy consumption reduction target is less for those who are
more efficient and more for the less efficient units.
Further, the scheme incentivizes units to exceed their specified SEC improvement
targets. To facilitate this, the scheme provides the option for industries who achieve
superior savings to receive energy savings certificates for this excess savings, and to
trade the additional certified energy savings certificates with other designated
consumers who can utilize these certificates to comply with their specific energy
consumption reduction targets. Energy Savings Certificates (ESCerts) so issued will be
tradable at Power Exchanges. The scheme also allows units which gain ESCerts to bank
them for the next cycle of PAT, following the cycle in which they have been issued.
The number of ESCerts which would be issued would depend on the quantum of energy
saved over and above the target energy savings in the assessment year.
After completion of baseline audits, targets varying from unit to unit ranging from about 3
to 7% are set and need to be accomplished during the 3 year cycle; after which new cycle
with new targets will be proposed. Failing to achieve the specific energy consumption
targets in the time frame would attract penalty for the non-compliance under Section
26 (1A) of the Energy Conservation Act, 2001 (amended in 2010). For ensuring the
compliance with the set targets, system of verification and check-verification will be
carried out by empanelment criteria of accredited energy auditors.
…………………….5 marks
_______________________ 10
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
S –5 In a heat treatment shop, steel components are heat-treated in batches of 80 Tons. The
heat treatment cycle is as follows;
a) Calculate the efficiency of the furnace, if the specific heat of steel is 0.12 kcal/kg OC
and fuel oil consumption per batch is 1400 litres.
b) Due to high cost of oil, the plant management decides to convert to a lower operating
cost LPG fired furnace lined on the inside with ceramic fibre insulation and with an
operating efficiency of 80%, for same requirement. The investment towards installation of
the new furnace is Rs. 50 lakhs. Calculate the Return on Investment, if the plant operates
two batches per day and 250 days in a year.
a. Efficiency of Furnace:
Useful heat supplied to steel - 80000 x 0.12 x (850 – 30)
= 7872000 kcal/batch
…………………….1 mark
Total heat supplied by fuel - 1400 x 0.92 x 10200
= 13137600 kcal/batch
Efficiency of Furnace - 7872000/12067824 = 59.9%
…………………….1 mark
b. Return on Investment (RoI):
Cost of operating fuel oil furnace - 1400 x 46 = Rs. 64400/batch
Efficiency of new LPG furnace - 80%
Heat supplied in new LPG furnace - 7872000/0.8
_______________________ 11
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
= 9840000 kcal/batch
Equivalent LPG consumption - 9840000/12500
= 787.2 kg/batch
…………………….1 mark
Cost of operating LPG Furnace - 787.2 x 75
=Rs. 59040/batch
Cost saving per batch - 64400 – 59040 =Rs. 5360/-
Annual cost saving - 5360 x 2 x 250
=Rs. 26,80,000/-
…………………….1 mark
Investment for new furnace - Rs. 50 Lakhs
Return on Investment (RoI) - (26.8/50)*100 = 53.6%
…………………….1 mark
S–6 In a 100 TPD Sponge Iron plant, the sponge iron is fed to the Induction melting furnace,
producing molten steel at 88% yield. The Energy consumption details are as follows:
Factory Boundary
Electricity for
Induction Melting
130 TPD Coal Furnace
4500 kcals/kg
100 TPD Sponge
Induction Melting
Iron Ore Iron Molten
Sponge Iron Kiln Furnace
steel
Grid Electricity Yield: 88%
120 kWh/t of
Sponge iron
_______________________ 12
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
Molten Steel Production from the Induction melting furnace per day
_______________________ 13
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
…………………….1 mark
PEP = (RYEE – current year energy)/RYEE = (23011 – 23834)/23011
= (-) 0.0369 ie (-) 3.7 %
…………………….1.5 marks
Since the PEP is negative, it implies that the energy conservation measure did not yield
reduction in energy consumption, action to be taken to improve the plant performance.
…………………….1.5 marks
S-8 List down any five Designated Consumers notified under the Energy Conservation Act.
Ans
(1) Aluminium, (2) Cement, (3) Chloralkali, (4) Fertiliser, (5) Steel, (6) Pulp & Paper,
(7)Thermal Power Plants, (8) Textile, (9) Railways.
…………………….5 marks
( any 5 of the above and each one carries one mark)
L - 1 Saturated steam at 1 atm is discharged from a turbine at 1200 kg/h. Superheated steam at 300 0C
and 1 atm is needed as a feed to a heat exchanger. To produce it, the turbine discharge stream is
mixed with superheated steam at 400 0C, 1 atm and specific volume of 3.11 m3/kg.
Calculate the amount of superheated steam at 300 0C produced and the volumetric flow rate of the
400 0C steam.
Ans Solution
1. Mass balance of water
1200 + m1 = m2 ………………………………………… (1)
…………………….1 mark
2. Energy balance
(1200 kg/h)(2676 kJ/kg) + m1(3278 kJ/kg)
_______________________ 14
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
…………………….4 marks
o
3. Volumetric flow rate of 400 C steam
The specific volume of steam at 400 C and 1 atm is 3.11 m3/kg. The volumetric flow rate is
calculated as follows:
(2341.2 kg/h)(3.11 m3/kg)
= 7281.1 m3/h
…………………….4 marks
L –2 The energy consumption and production patterns in a chemical plant over a 9 month period is provided in
the table below;
Month 1 2 3 4 5 6 7 8 9
Production in Tonnes / month 493 297 381 479 585 440 234 239 239
Energy Consumption MWh /month 78.2 75.7 76.3 76.1 78.1 70.7 73.7 64.4 72.1
th
Estimate the cumulative energy savings at end of the 9 month and give your inference on the
result ? ( consider 9 month data for evaluation for predicted energy consumption)
Ans It is required to use the equations Y= mX + C and
nC + mΣX = ΣY
cΣX + mΣX2 = ΣXY
X=
Y =Energy
Production in
Month Consumption MWh X2 XY
Tonnes /
/month
month
1 493 78.2 243049 38574.12
2 297 75.7 88209 22479.51
3 381 76.3 145161 29076.88
4 479 76.1 229441 36436.09
5 585 78.1 342225 45671.42
6 440 70.7 193600 31110.53
7 234 73.7 54756 17240.63
8 239 64.4 57121 15402.96
9 239 72.1 57121 17228.98
3387 665.3 1410683 253221
_______________________ 15
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
…………………….2 marks
c = (665.3-3387m)/9
m = 0.021 and
c = 66.1
y = 0.021x + 66.1
…………………….3 marks
Production in E cal Y =
Tonnes / 0.021x + Difference
Month month x Eactual 66.1 CUSUM
1 493 78.2 76.45 1.75 1.75
2 297 75.7 72.34 3.36 5.11
3 381 76.3 74.10 2.20 7.31
4 479 76.1 76.16 -0.06 7.25
5 585 78.1 78.39 -0.28 6.97
6 440 70.7 75.34 -4.64 2.33
7 234 73.7 71.01 2.69 5.01
8 239 64.4 71.12 -6.72 -1.71
9 239 72.1 71.12 0.98 -0.73
…………………….4 marks
Since the CUSUM value at the end of 9th month is negative, the plant has not achieved any net energy
savings and action has to be taken to determine reason for no performance of the encon option.
…………………….1 mark
L - 3 Explain the following
a) Dry Bulb Temperature and Wet bulb Temperature
e) CUSUM
_______________________ 16
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
• Dry bulb Temperature is an indication of the sensible heat content of air-water vapour
mixtures
• Wet bulb Temperature is a measure of total heat content or enthalpy. It is the temperature
approached by the dry bulb and the dew point as saturation occurs.
…………………….2 marks
b) Maximum Demand and Power Factor
• Gross calorific value assumes all vapour produced during the combustion process is fully
condensed.
• Net calorific value assumes the water leaves with the combustion products without being
fully condensed.
• The difference being the latent heat of condensation of the water vapour produced during
the combustion process.
…………………….2 marks
d) 5S:
Housekeeping. Separate needed items from unneeded items. Keep only what is
immediately necessary item on the shop floor.
Workplace Organization. Organize the workplace so that needed items can be easily and
quickly accessed. A place for everything and everything in its place.
Cleanup. Sweeping, washing, and cleaning everything around working area immediately.
Discipline. Everyone understands, obeys, and practices the rules when in the plant.
d) Return on Investment:
This is a broad indicator of the annual return expected from initial capital investment,
_______________________ 17
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
expressed as a percentage.
…………………….1 mark
…………………….2 marks
2 Ultrasonic Flow Meter uses the principle of____& ____ Fill in the blanks
Non Contact Infrared Thermometer cannot measure
3 True/False
temperature of objects placed in hazardous places
To measure the RPM of a Flywheel, ______ type of RPM
4 meter is used and for a visible shaft-end _______ type of Fill in the blanks
RPM meter is used.
In a switch yard, _____ instrument is used to identify the
5 Fill in the blanks
loose joints and terminations
Every Designated Consumer shall have its first energy
audit conducted by ________ Energy Auditor within
6 Fill in the blanks
______ months of notification issued by the Central
Government
_______________________ 18
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
_______________________ 19
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
L - 5 A company has to choose between two projects whose cash flows are as indicated
below;
Project 1:
Project 2:
Which project should the company choose? The annual discount rate is 12%.
_______________________ 20
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
Ans
Year Project 1 Project 2
Outgo Saving NPV Outgo Saving NPV
0 15.0 0 =-15.0 14.0 0 = -14
1 0 4.0 = (4 / (1+.12)1 0.2 3.5 = (3.3 / (1+.12)1
= 3.571 = 2.95
2 0.5 4.0 = (3.5 / (1+.12)2 0.2 3.5 = (3.3 / (1+.12)2
= 2.79 = 2.63
3 0 4.0 = (4 / (1+.12)3 0.2 3.5 = (3.3 / (1+.12)3
= 2.84 = 2.35
4 0.5 4.0 = (3.5 / (1+.12)4 5 3.5 = (-1.5 / (1+.12)4
= 2.22 = -0.95
5 6 4.0 = (-2 / (1+.12)5 0.2 3.5 = (3.3 / (1+.12)5
= -1.13 = 1.87
6 0.5 4.0 = (3.5 / (1+.12)6 0.2 3.5 = (3.3 / (1+.12)6
= 1.77 = 1.67
7 0 4.0 = (4 / (1+.12)7 0.2 3.5 = (3.3 / (1+.12)7
= 1.81 = 1.49
8 0.5 9 (4+5) = (8.5 / (1+.12)8 0.2 5.5 = (5.3 / (1+.12)8
= 3.43 (3.5+2) = 2.14
NPV = + 2.301 @12% = + 0.15
d. Prepare a PERT chart, estimate the duration of the project and identify the
critical path.
_______________________ 21
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
e. What are the Earliest Start, Latest Start and Total Float of activity ‘H’?
f. What would be the project duration if activity ‘H’ got delayed by 3 weeks?
D 5 G
B 5 9 J, 6
A 6 F,12 I ,5
8 c
12 H 8
OR
…………………….6 marks
…………………….1 mark
_______________________ 22
Bureau of Energy Efficiency
Paper 1 –Set A with Solutions
…………………….1 mark
c. For activity H, Early Start is 20, Latest Start is 22 and Total Float is 2 weeks.
…………………….1 mark
_______________________ 23
Bureau of Energy Efficiency
Paper 1 SET A
3. Which of the following has the lowest energy content in terms of MJ/kg
a) LPG b) Diesel
c) Bagasse d) Furnace oil
4. _________ and _______ consume major share of Natural Gas consumption in India.
a) Domestic sector and Transport sector
b) Transport sector and Fertilizer Industry
c) Power Generation and Fertilizer Industries
d) Domestic Sector and Fertilizer Industries
6. Which of the following designated consumer has the lowest energy intensity?
a) Aluminium b) Iron and Steel
c) Cement d) Chlor alkali
8. Which of the following does not meet the Designated Consumer criteria?
a) Pulp and Paper Industries with minimum annual energy consumption of 30,000
TOE.
b) Cement Industries with minimum annual energy consumption of 30,000 TOE.
c) Chlor- Alkali Industries with minimum annual energy consumption of 7500
TOE.
_______________________ 1
Bureau of Energy Efficiency
Paper 1 SET A
15. As per Energy Conservation Act, 2001 appointment of BEE Certified Energy Manger is
mandatory for
a) all State designated agencies b) all large Industrial consumers
c) all designated consumers d) all commercial buildings
16. A waste heat recovery system requires Rs. 50 lakhs investment and Rs. 2 lakhs per year
to operate and maintain. If the annual savings is Rs. 22 lakhs, the payback period will
be
a) 2.28 years b) 2.5 years
c) 3 years d) 10 years
17. What is the heat content of the 200 liters of water at 5000C in terms of the basic unit
of energy in Kilo Joules
a) 30000 b) 23880
c) 10000 d) 41870
Note: 1 Mark is awarded to all candidate who have attempted this question.
18. Which of the following GHGs has the longest atmospheric life time
a) CH4 b) SF6
c) CFC d) PFC
_______________________ 2
Bureau of Energy Efficiency
Paper 1 SET A
21. Which of the following equation is used to calculate the future value of the cash flow?
a) NPV (1 – i)n b) NPV / (1 – i)n
n
c) NPV (1 + i) d) NPV/ (1 + i)n
22. For investment decision, ROI must always be _____ prevailing interest rate.
a) Lower than b) Higher than
c) Equal to d) No relation
23. Large scattering on production versus energy consumption trend line indicates
a) Poor process control b) Inefficient equipment
c) Inefficient process d) None of the above
25. The rotor axis is aligned with the wind direction in a wind mill by ________ control
a) yaw b) pitch
c) disc break d) all of the above
27. The lowest theoretical temperature to which water can be cooled in a cooling tower is
a) Difference between DBT and WBT of the atmospheric air
b) Average DBT and WBT of the atmospheric air
c) DBT of the atmospheric air
d) WBT of the atmospheric air
28. In a solar thermal power station Molten salt is preferred as it provides an efficient low
cost medium to store ______ energy
a) Electrical b) Thermal
c) Kinetic d) Potential
29. From Voltage, Amps and Power factor given in the name plate of a motor, one can
calculate ________.
a) Rated output power b) Shaft power
c) Rated input power d) Both (b) & (c)
31. If asset depreciation is considered, then net operating cash inflow would be
a) lower b) higher
c) no effect d) none of the above
34. A three phase induction motor is drawing 10 Ampere at 440 Volts. If the operating
_______________________ 3
Bureau of Energy Efficiency
Paper 1 SET A
power factor of the motor is 0.9 and the efficiency of the motor is 95%, then the
mechanical shaft power of the motor is
a) 3.76 KW b) 4.18 KW
c) 6.51 KW d) 7.21 KW
35. For an activity in a project, Latest start time is 8 weeks and Latest finish time is 12
weeks. If the earliest finish time is 9 weeks, Slack time for the activity is ____.
a) 3 weeks b) 4 weeks
c) 1 week d) none of the above
38. If the fixed energy consumption of a company is 2000 kWh per month and the line slope
of the energy (y) versus production (x) chart is 0.3, then the energy consumed in kWh
per month for a production level of 60,000 tons/month is _______.
a) 16,000 KWh b) 18,000 KWh
c) 22,000 KWh d) none of the above
41. Which equipment does not come under mandatory labelling program?
a) Room Air conditioners b) Frost free refrigerator
c) Induction motors d) Distribution transformer
46. To reduce the distribution losses within a plant, the capacitors should be located
a) Closest to the load b) Farthest from the load
c) In the substation d) Before the billing meter
_______________________ 4
Bureau of Energy Efficiency
Paper 1 SET A
49. When the evaporation of water from a wet substance is zero, the relative humidity of
the air is likely to be
a) 0% b) 100%
c) 50% d) unpredictable
50. Which of the following type of collector is used for low temperature systems?
a) Flat plate collector b)Line focusing parabolic collector
c) Parabolic trough collector d) None of the above
S-1 List five equipment and appliances covered under Standards and Labelling program.
a) When it is raining, there is a substantial difference between the dry and wet bulb
temperatures.
b) The specific gravity of light diesel oil is given in kg/m3
c) The major constituent of LNG is propane
d) Evaporative cooling of space requires use of refrigerant R134a
e) HSD needs preheating to increase viscosity
S – 3 For installing a recuperator in a furnace, the plant has assessed the following time estimates
Optimistic Time : 2.5 weeks
Most Likely Time : 3 weeks
Pessimistic Time : 3.5 weeks
Find out the “Expected Time”, “Standard Deviation” and “Variance” to complete the activity
(2 +1.5+1.5 Marks)
_______________________ 5
Bureau of Energy Efficiency
Paper 1 SET A
Ans Expected time = (Optimistic Time + 4 X Most Likely Time + Pessimistic Time) / 6
= (2.5 + 4 x 3 + 3.5)/ 6
=3
Standard Deviation = (3.5-2.5)/6 = 1/6 = 0.167
Variance = {(PT-OT/6)} 2
= 1 / 36 = 0.0278
S-4 A thermal power plant uses 0.72 kg of coal to generate one KWh of electricity. If the coal
contains 38% carbon by weight, calculate the amount of CO2 emission/KWh under complete
combustion.
S-5 A solar photovoltaic power plant is installed with 350 Watts panel of size 1.5 m x 1.5 m in
roof top area of a building having dimension of 9 m x 10m. If solar insolation is 1,000 W/m2,
calculate the panel conversion efficiency?
S – 6 A paint drier requires 75.4 m3/min of air at 93°C, which is heated in a steam-coil unit. How
many kg of steam at 4 bar does this unit require per hour? The density of air is 1.2 kg/m3
and specific heat of air is 0.24 kcal/kg°C. The ambient temperature is 32°C.
Ans Solution:
Air flow rate = 75.4 m3/min * 60 = 4524 m3/hr
Air flow rate = 4524 * 1.2
= 5428.8 kg/hr
_______________________ 6
Bureau of Energy Efficiency
Paper 1 SET A
S – 7 An ESCO company is required to invest in a waste heat recovery project, which is expected to
yield an annual saving of Rs.10,00,000 and the life of the equipment is 7 years. If the ESCO
expects 30% IRR on this project, calculate the investment required to be made.
or
Investment = Rs.1,000,000/year (P/AIN Factor)
= Rs.1,000,000/year (2.8021) = Rs. 2,802,100
Thus, we can pay Rs.2,802,100 for the Waste Heat Exchanger and still have a positive NPV.
Given Data: (1 kWh = 860 kcal, GCV of coal= 3450 kCal/kg, GCV of furnace oil= 10,000
kcal/kg, GCV of HSD= 10,500 kcal/kg, GCV of rice husk= 3100 kcal/kg, 1 kg oil equivalent
= 10,000 kcal)
_______________________ 7
Bureau of Energy Efficiency
Paper 1 SET A
L-1 Describe the stages of Gasification of Biomass process with a pictorial diagram and
reaction equations?
L - 3 a) Write down the steps for computing energy savings using CUSUM over a period.
(4 Marks),
b) Develop a table using a CUSUM technique to calculate energy savings for 8 months
period for a production level of 2000 MT per month. Refer to field data given in the
table below. (6 marks)
Month Actual SEC kWh/MT Predicted SEC kWh/MT
b) Estimate the savings accumulated from use of the heat recovery system.
_______________________ 8
Bureau of Energy Efficiency
Paper 1 SET A
Positive savings i.e. savings in energy consumption over a period of eight months are
56 x 2000 = 112,000 kWh
Present scenario :
Concentration of solids in product (output) = 30 wt% = 0.3
Mass balance across the evaporator :
Amount of product (output) from the evaporator = 35 / 0.3
= 116.7 Kg
Design scenario :
Concentration of solids in product (output) = 45 wt% = 0.45
Mass balance across the evaporator :
Amount of product (output) from the evaporator = 35 / 0.45
= 77.8 Kg
L -5 A process plant is planning to implement a waste heat recovery project. The various
activities from procurement to commissioning are given in the table below along with their
duration and dependency.
_______________________ 9
Bureau of Energy Efficiency
Paper 1 SET A
b) Early start (ES), Early Finish (EF), Latest start (LS), Latest finish (LF) and slack for all
the activities.
Slack
Activity Duration ES EF LS LF (LS-ES) or
(LF-EF)
A 3 0 3 0 3 0
B 5 0 5 6 11 6
C 4 3 7 3 7 0
D 6 3 9 5 11 2
E 5 7 12 7 12 0
_______________________ 10
Bureau of Energy Efficiency
Paper 1 SET A
F 3 7 10 10 13 3
13
G 2 9 11 11 2
H 1 12 13 12 13 0
I 2 13 15 13 15 0
X1 and X2 are dummy activities
c) Critical Path : A- C- E- H- I
➢ Grid electricity Imported = (5 x 106 kWh)x (860 kcal/kWh) = (+) 43 x 108 kcals/year
➢ 6
Power generated from CPP = (36 x 10 kWh)x (3500 kcal/kWh) = (+) 1260 x 108 kcals/year
➢ 3
Coal imported for process = (5000 x 10 kg)x (4500 kcal/kg) = (+) 225 x 108 kcals/year
➢ 6
Power exported to grid = (11 x 10 kWh)x (3500 kcal/kWh) = (-) 385 x 108 kcals/year
➢ Coal fines exported to neighbour = (1000 x 10 kg)x (4500 kcal/kg) = (-) 45 x 108 kcals/year
3
_______________________ 11
Bureau of Energy Efficiency
Paper 1 Code : GREEN
7. Under the Energy Conservation Act, the designated consumer is required to get the mandatory
energy audit conducted by
a) certified energy manager b) certified energy auditor
c) accredited energy auditor d) BEE
8. Stroboscope is an instrument for measuring
a) steam flow b) composition of flue gas c) speed d) pressure
9. The benchmarking parameter for a vapour compression refrigeration system is
a) kW / kg of refrigerant used b) kcal / m3 of chilled water
c) BTU / TR d) kW / TR
10. If 1 kWh of electrical energy is used to heat 10 kg of ice at 0o C, what will be the temperature of
water after melting? (Latent heat of fusion of ice is 80 kcal/kg)
a) 0oC b) 6oC c) 86oC d) none of the above
11. If feed of 15 tonnes per hour at 6% concentration is fed to an evaporator, the product obtained at
1
_______________________
Bureau of Energy Efficiency
Paper 1 Code : GREEN
a) 3 b) 9 c) 0.9 d) 4.5
12. The discount rate is used as an input in determining _________.
a) NPV b) IRR c) payback period d) all of the above
13. The rate of energy transfer from a higher temperature to a lower temperature is measured in
14. The cost of an economizer is Rs. 2 lakhs. The simple payback period (SPP) in years considering
annual savings of Rs 1,10,000 and annual maintenance cost of Rs 10,000 is ___________.
a) 1.8 b) 2.5 c) 2 d) 0.5
15. 1 kg of wood contains 15% moisture and 5% hydrogen by weight. How much water is evaporated
during complete combustion of 1kg of wood?
a) 0.6 kg b) 200 g c) 0.15 kg d) none of the above
16. In an industry the average electricity consumption is 10 lakh kWh for a given period. The average
production is 90,000 tons with a specific electricity of 10 kWh/ton for the same period. The fixed
electricity consumption for the plant is
a) 1,00,000 kWh b) 9,90,000 kWh c) 10,000 kWh d) none of the above
17. The cost of retrofitting a humidification system with an energy efficient one costs Rs. 20 lakhs.
The net annual cash flow is Rs. 5 lakhs. The return on investment is ________.
18% b) 25% c) 15% d) 33.33%
18. The theoretical amount of electricity required to heat 500 litres of brine solution with a specific
gravity of 1.2 and specific heat of 1 kcal/kg K from 30oC to 70 oC through resistance heating
is_________
a) 27.9 kWh b) 23.3 kWh c) 20 kWh d) none of the above
2
_______________________
Bureau of Energy Efficiency
Paper 1 Code : GREEN
24. Which of the following has the highest Reserve to Production (R/P) ratio in India?
a) Lignite
b) Petroleum
c) Coal
d) Natural gas
25. SI unit for energy is_____________
a) Watt
b) Kilogram
c) Newton
d) Joule
26. Which of the following has the lowest energy content in terms of MJ/kg?
a) LPG
b) Diesel
c) Furnace Oil
d) Coal
27. Which of the following industries has the highest Specific Electrical Energy Consumption?
a) Aluminum
b) Sugar
c) Paper & Pulp
d) Cement
28. Select the wrong statement.
a) Energy Efficiency and Energy Conservation are distinct and interrelated
b) Unscheduled power interruption is an Energy conservation measure
c) Productivity improvements leads to energy conservation
d) Energy Efficiency is an integral part of energy conservation
29. _____ in Centre and______ _ in States are mandated to implement the provisions of The Energy
Conservation Act, 2001
a) BEE and NPC
b) BEE and DISCOM
c) BEE and SERC
d) BEE and SDA
30. Energy Conservation Building Code (ECBC) sets;
a) Minimum Energy Efficiency Standards for design and Construction of Buildings
b) Green Building Rating System
c) Municipal DSM Regulations
d) Incentives for energy efficient buildings
31. Which of the following is one of the schemes of BEE under Energy Conservation Act ?
a) Standards and Labelling
b) Availability based Tariff
c) Standard of Performance of DISCOMs
d) Renewable Energy Certificates
32. Which one of the following is not a Designated Consumer category under PAT ?
a) Paper and Pulp Industries
b) Cement Plants
c) Chlor Alkali Plants
d) Sugar Plants
33. Steam contains 10% moisture by mass, its dryness fraction x is _________.
3
_______________________
Bureau of Energy Efficiency
Paper 1 Code : GREEN
a) (i) & (iv) b) (i) & (ii) c) (iii) & (iv) d) (i) & (iv)
44. A building intended to be used for commercial purpose will be required to follow Energy
conservation building code under Energy Conservation Act, 2001 provided its
4
_______________________
Bureau of Energy Efficiency
Paper 1 Code : GREEN
The expected return is 10%. Evaluate the Net Present Value and comment on the feasibility of the
project?
Solution:
NPV = {-500,000+(200,000/1.10)+[300,000/(1.1)2]+[200,000/(1.1)3]}
= (-500,000+181818+247934+150263)
= 80015
NPV is positive Rs. 80,015; therefore, the proposed investment for the new energy saving project is
viable and attractive.
5
_______________________
Bureau of Energy Efficiency
Paper 1 Code : GREEN
A continuous centrifuge separates 36,000 kg of whole milk containing 4% fat in 6-hour period into
S3
skim milk with 0.40% fat and cream with 40 % fat. Find out the flow rates of whole milk, cream and
skim milk using mass balance.
Ans:
Mass in
The mass of skim milk is (6000 - X) and its total fat content is 0.0040 (6000 - X)
Material balance on fat:
Fat in = Fat out 6000 x 0.04
= 0.0040(6000 - X) + 0.40X; solving this,
X = 545 kg/hr
So that the flow of cream is 545 kg / hr and skim milk (6000- 545) = 5455 kg/hr.
A water pumping station fills a tank at a fixed rate. The head and flow rate are constant and hence
S-4
the power drawn by the pump is always same. The pump delivers 80 litres per second. The power
consumption was measured as 84 kW.
Calculate the energy consumption for pumping 2880 kL of water to the reservoir.
Ans
Time taken to pump water in hours = (2880 × 103 lit)
(80 lit/s x 3600 sec/hr)
= 10 hours
Ans Volume of coal delivered per hour = Area x Length travelled per second
= 0.9 m x 0.15 m x 0.8 m/s
6
_______________________
Bureau of Energy Efficiency
Paper 1 Code : GREEN
S-6 In a textile industry, 25,000 kg/hr water is currently being heated from 28 oC to 80 oC by indirect
heating of steam in dyeing machines.
It is proposed to recover heat from the hot effluent and generate hot water at 45 oC which would be
further raised to 80 oC by steam.
Estimate the reduction in steam in kg/hr considering the latent heat of steam as 520 kcal/kg in both
the cases.
Ans Ans:
Without heat recovery
Heating required (Q1) = mCpT
= 25000 x 1 x (80-28)
= 13,00,000 kcal/hr
Steam required = 13,00,000 / 520
= 2500 kg/hr
After heat recovery
Heating required (Q2) = 25000 x 1 x (80 – 45)
= 8,75,000 kcal/hr
Steam required = 8,75,000 / 520
= 1682.7 kg/hr
Reduction in steam required = 2500 - 1682.7 = 817.3 kg/hr
Briefly explain the difference between flat plate collector and evacuated tube collector.
S7
(Book 1, Page 264-265)
7
_______________________
Bureau of Energy Efficiency
Paper 1 Code : GREEN
L1 a) A sample of fuel being used in a boiler is found to contain 40% carbon and 23% ash. The
refuse obtained after combustion is analyzed and found to contain 7% carbon & the rest is
ash. Compute the percentage of the original carbon in fuel which remains as unburnt in the
refuse. (5 Marks)
b) During an ESP performance evaluation study, the inlet gas stream to ESP is 2,89,920
Nm3/hr and the dust loading is 5,500 mg/ Nm3. The outlet gas stream from ESP is
3,01,100 Nm3/hr and the dust loading is 110 mg/Nm3. How much fly ash is collected in
the system in kg/hr? (5 Marks)
a)
Let the quantity of Refuse sample = 100 kg
Amount of unburnt Carbon in Refuse = 7 kg
Amount of Ash in the Refuse = 93 kg
Total ash in the fuel that has come into the Refuse = 23% of fuel
iii) Fly Ash = Inlet gas stream dust – Outlet gas stream dust
= 1594.56 – 33.12 = 1561.44 kg/hr
L2 Write short note on any two of the following. (Each 5 Marks)
8
_______________________
Bureau of Energy Efficiency
Paper 1 Code : GREEN
L3 Based on the following network diagram, identify the total number of paths with duration, critical path,
and float for each path.
1 Mark each path x 5 = 5 Mark
1 Mark for identifying critical path = 1 Mark
1 Mark for float of each path x 4 = 4 Mark
Solution:
The above network diagram has five paths; the paths and their duration are as follows:
Since the duration of the first path given below is the longest, it is the critical path.
The float for the second path “Start ->D -> E ->F -> End” =
Duration of the critical path – duration of the path “Start ->D -> E ->F -> End” = 46-33 = 13
Hence, the float for the second path is 13 days.
Using the same process, we can calculate the float for other paths as well.
Float for the third path = 46 – 41 = 5 days.
Float for the fourth path = 46 – 28 = 18 days.
Float for the fifth path = 46 – 31 = 15 days.
L4 In the washing process of an automobile plant, electricity is being used to heat 5000 litres/hr of water
by 8 0C. The industry is planning to convert from Electrical heating to LPG heating.
Other Parameters:
Annual operating hours = 6000 hours
Efficiency of indirect heating with LPG = 85%
Efficiency of electrical heating = 95%
Calorific value of LPG = 12,000 kcal/kg
Landed cost of LPG = Rs.60/kg
Cost of electricity = Rs.8/kWh
a) If electrical heating is replaced with LPG heating, with an investment is Rs.15 lakhs, compute the
simple payback period. ( 6 Marks)
b) Also, calculate the CO2 emissions in both the cases considering the emission factors for LPG as 3
9
_______________________
Bureau of Energy Efficiency
Paper 1 Code : GREEN
IRR = 15.24 %
Based on IRR, the Option A has higher IRR value and the company may opt for Option A.
10
_______________________
Bureau of Energy Efficiency
Paper 1 Code : GREEN
1. Biomass a. Radiation
2. CNG b. Distribution Loss Reduction
3. HVDS c. Oxidation
4. Cement d. Sankey Diagram
5. Combustion e. ISO 50001
6. Energy Balance f. Designated consumer
7. kWh/ton of product g. Transport
8. Objectives, targets & action h. Carbon neutral
plans
9. Performance Contracting i. Benchmarking
10. Surface Heat Loss j. ESCO
(Each 1 Mark)
Solution:
11
_______________________
Bureau of Energy Efficiency