EN209 – Energy and Sustainability

Energy Efficiency

Course Instructor:
Dr.Farrukh Khalid
School of Energy Science and Engineering, IITG

© Serdar Celik 2023

 Energy Efficiency

© Serdar Celik 2023

Sustainable Energy: Engineering Fundamentals and Applications

Introduction
Buildings

OUTLINE Industry
Transportation
Summary
© Serdar Celik 2023
3
Sustainable Energy: Engineering Fundamentals and Applications

The nuance between energy conservation and energy

efficiency

Energy efficiency in buildings, industry, and

transportation sectors

HVAC systems and load calculation for buildings

LEARNING Standards and rating systems for building energy

OBJECTIVES performance

Use of combined heat and power plants in industry

The importance of industrial recycling

Fuel economy comparison of different vehicles

© Serdar Celik 2023

4
INTRODUCTION
▪ Energy conservation and energy efficiency are two phrases which are commonly interchangeably used
although there is a basic difference between the two terms.
▪ Energy conservation is an action of using less amount of energy, either through personal choices, or because
of necessities.
▪ Energy efficiency is the engineering outcome of technologies that consume less energy to conduct the same
function without giving up from the standards.
▪ Energy efficiency can also be misleadingly grouped together with renewable energy technologies. Energy
efficiency is not a renewable energy source. Renewable energy systems generate energy, while energy
efficiency is a term associated with consuming energy in a way that the consumption is less to achieve the
same amount of output from the system that is utilized.
▪ Energy efficiency can sometimes be disregarded. It is the low hanging fruit towards sustainability and a
cleaner ecosystem.
▪ Efforts to enhance energy efficiency of buildings, industry, vehicles, and electrical devices used in various
sectors such as manufacturing, agriculture, health, and power generation will help in achieving SDGs.

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 5
BUILDINGS
▪ Building energy consumption adds up to significant numbers globally.
▪ This indicates that any improvement in building technologies and enhancement in building
energy efficiency would result in remarkable reduction in total global energy consumption and
carbon emissions.
▪ Many municipalities all around the world are trying to promote public awareness on building
energy use. Some are implementing smart city programs with the purpose of making the cities
more citizen-friendly and sustainable.
▪ Some of the commonly used phrases used for buildings that are environment-friendly are:
₋ Green buildings
₋ Sustainable buildings
₋ Smart buildings
₋ Net-zero buildings

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 6
BUILDINGS
Some factors that affect the energy performance of the building are:
▪ Location
▪ Weather
▪ Building configuration
▪ Equipment and devices in the building
▪ Occupancy
Some effective ways in improving building energy efficiency are:
▪ Sealing air leaks and better insulation
▪ Installing energy-efficient windows
▪ Switching to high performance lighting
▪ Utilizing passive solar design for heating and cooling
▪ Installing green roofs

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 7
BUILDINGS

Figure 14.3. Types of air conditioners.

Source: U.S. Department of Energy.
Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 8
BUILDINGS

Figure 14.7. Different types of heating systems.

Source: U.S. Department of Energy.
Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 9
LIGHTING AND APPLIANCES

Figure 14.11. Energy use of

standard household appliances.
Source: U.S. EPA.

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 10
Example 14.4 Energy efficiency of domestic refrigerators
Consider a domestic refrigerator with a cooling capacity of 420 W and a compressor power rating of 150 W. If the cooling capacity is determined by the
heat gain of the refrigerator, under steady state conditions determine:
a. the coefficient of performance (COP) for the refrigerator
b. the annual cost of electricity consumption of the refrigerator if the compressor runs for 14 hours a day and cost of electricity is 7.6 cents per kWh
c. the annual cost of electricity as in part (b), if the overall heat transfer coefficient, U, is reduced by 10% with the improvements on the refrigerator
cabinet (i.e. cabinet is insulated with vacuum insulated panels)

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 11
Solution
a. COP of the refrigerator is determined by using the given cooling capacity and compressor power:
𝑄ሶ 𝑐𝑜𝑜𝑙𝑖𝑛𝑔 420 𝑊
𝐶𝑂𝑃 = = = 2.8
𝑊ሶ 𝑐𝑜𝑚𝑝𝑟𝑒𝑠𝑠𝑜𝑟 150 𝑊

b. Annual cost of electricity is determined by:

𝐶𝑜𝑠𝑡 = 𝑊ሶ 𝑐𝑜𝑚𝑝𝑟𝑒𝑠𝑠𝑜𝑟 𝐴𝑛𝑛𝑢𝑎𝑙 𝑜𝑝𝑒𝑟𝑎𝑡𝑖𝑛𝑔 ℎ𝑜𝑢𝑟𝑠 𝑈𝑛𝑖𝑡 𝑝𝑟𝑖𝑐𝑒

ℎ 𝑑𝑎𝑦𝑠 $ 1 𝑘𝑊ℎ $
𝐶𝑜𝑠𝑡 = 150 𝑊 14 365 0.076 = 58.25
𝑑𝑎𝑦 𝑦𝑟 𝑘𝑊ℎ 103 𝑊ℎ 𝑦𝑟

c. Cooling capacity is equal to heat gain rate of the refrigerator cabinet under steady state conditions:
𝑄ሶ 𝑐𝑜𝑜𝑙𝑖𝑛𝑔 = 𝑄ሶ 𝑔𝑎𝑖𝑛 = 𝑈𝐴(𝑇𝑎𝑚𝑏𝑖𝑒𝑛𝑡 − 𝑇𝑐𝑎𝑏𝑖𝑛𝑒𝑡 )
In this case, U-value is reduced by 10%. With the same compressor COP, this also translates to 10% less energy
consumption by the compressor. Then,
ℎ 𝑑𝑎𝑦𝑠 $ 1 𝑘𝑊ℎ $
𝐶𝑜𝑠𝑡 = 0.9 150 𝑊 14 365 0.076 = 52.4
𝑑𝑎𝑦 𝑦𝑟 𝑘𝑊ℎ 103 𝑊ℎ 𝑦𝑟

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 12
STANDARDS, CODES, AND
RATING SYSTEMS

▪ ENERGY STAR (U.S.)

▪ LEED (U.S. and Canada)
▪ BREEAM (U.K.)
▪ Green Globes (U.S. and Canada)
▪ CASBEE (Japan)
▪ Green Star (Australia)

© Serdar Celik 2023 Sustainable Energy: Engineering Fundamentals and Applications

INDUSTRY
There are many industries who focus on energy efficiency. Some of these
industries are:
▪ Aerospace
▪ Aluminum
▪ Asphalt
▪ Cement
▪ Dairy
▪ Fertilizer
▪ Glass
▪ Paper
▪ Petrochemical
▪ Pharmaceutical
▪ Plastics
▪ Steel
Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 14
INDUSTRY

Figure 14.14. Combustion turbine or reciprocating engine CHP system. Source: U.S. EPA.

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 15
INDUSTRY

Figure 14.15. Steam turbine CHP system. Source: U.S. EPA.

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 16
TRANSPORTATION
Example action plans addressing transportation energy efficiency and energy savings [15]:
▪ Promoting energy-efficient vehicles
▪ Developing benchmarking on alternative fuels and new technologies
▪ Developing and improving bicycle and pedestrian transport
▪ Reducing traffic density in cities: Discouraging use of automobiles
▪ Promoting public transport
▪ Developing and implement institutional restructuring for urban transport
▪ Strengthening maritime transport
▪ Strengthening rail transport
▪ Compiling transport data

[15] Asia Pacific Energy Portal, “National Energy Efficiency Action Plan (NEEAP) of Turkey, 2017-2023,” Republic of Turkey Ministry of Energy and
Natural Resources, Ankara, Mar. 2018.
Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 17
Example 14.6 Fuel economy comparison of different vehicles
Fuel consumption values of some vehicles are listed based on the data from Fuel Economy Guide 2021 on
fueleconomy.gov. The analysis assumes 15,000 miles of annual travel, with 55% city driving and 45% highway
driving. Unit price for gasoline is assumed to be $3.66. For each model:
a. Determine the combined fuel economy (mpg)
b. Calculate the annual fuel cost ($/yr)

Manufacturer, Model, Configuration mpg (City) mpg (Highway)

BMW Z4 sDrive30i / 2.0 L / 4 cyl 25 32
Chevrolet Corvette / 6.2 L / 8 cyl 15 27
Porsche 911 Carrera 4S / 3.0 L / 6 cyl 17 24
Nissan 370Z / 3.7 L / 6 cyl 17 26
Mini Cooper Convertible / 1.5 L / 3 cyl 26 37

© Serdar Celik 2023 18

Solution:
Combined mpg can be calculated by:
1
𝑚𝑝𝑔𝑐𝑜𝑚𝑏𝑖𝑛𝑒𝑑 =
0.55 0.45
+
𝑚𝑝𝑔𝑐𝑖𝑡𝑦 𝑚𝑝𝑔ℎ𝑖𝑔ℎ𝑤𝑎𝑦

Annual fuel cost is calculated as:

$ 𝐴𝑛𝑛𝑢𝑎𝑙 𝑚𝑖𝑙𝑒𝑎𝑔𝑒
𝐴𝑛𝑛𝑢𝑎𝑙 𝑓𝑢𝑒𝑙 𝑐𝑜𝑠𝑡 = 𝐶𝑜𝑠𝑡 𝑜𝑓 𝑓𝑢𝑒𝑙 𝑝𝑒𝑟 𝑔𝑎𝑙𝑙𝑜𝑛
𝑦𝑟 𝑚𝑝𝑔𝑐𝑜𝑚𝑏𝑖𝑛𝑒𝑑

Generating a table on a spreadsheet file with input values and columns for the output values being sought with
corresponding formulae yields the results as listed in the table below:
Annual Fuel Cost
Manufacturer, Model, Configuration mpg (Combined)
($/yr)
BMW Z4 sDrive30i / 2.0 L / 4 cyl 28 1961
Chevrolet Corvette / 6.2 L / 8 cyl 19 2890
Porsche 911 Carrera 4S / 3.0 L / 6 cyl 20 2745
Nissan 370Z / 3.7 L / 6 cyl 20 2745
© Serdar Celik 2023
Mini Cooper Convertible / 1.5 L / 3 cyl 30 19 1830
SUMMARY
▪ Energy conservation is a means of energy savings by giving up from one or more standards such as health,
comfort, productivity, or quality. It does not need a high-tech approach. This is an easy way of saving energy
by means of compromising.
▪ Energy efficiency on the other hand, requires research, technology enhancement, and product
development. It requires engineering. In fact, as the efficiency of a system increases and gets closer to its
saturation, improvement requires more rigorous engineering.
▪ Use of improved building insulation and energy-efficient air-conditioners, refrigerators, HVAC units,
furnaces, boilers, fans, blowers, pumps will lead to less heating, cooling, and ventilation energy
consumption.
▪ Improvement in industrial energy consumption can be achieved by taking measures such as employing
energy-efficient machinery, regulated energy demand, implementation of combined heat and power (CHP)
systems, and recycling.
▪ As for transportation energy efficiency; electric vehicles, alternative fuels, modern public transportation,
improved maritime and rail transportation, and expanded bicycle paths in cities are some of the steps being
undertaken by governments and municipalities worldwide.

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 20
QUESTIONS…

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications
 Conservation of Energy by High-Efficiency Electric Motors
Practically all compressors are powered by electric motors. Electric motors cannot convert the electrical energy
they consume into mechanical energy completely.

Motor efficiency range: 0.7 < ηmotor < .96. The portion of electric energy that is not converted to mechanical power is
converted to heat, which is mostly unusable
For example, assuming that no transmission losses occur:
• A motor with an efficiency of 80 % will draw an electrical power of 1/0.8 = 1.25 kW for each kW of shaft
power it delivers.
• If the motor is 95 % efficient, then it will draw 1/0.95 = 1.05 kW only to deliver 1 kW of shaft work.
• Therefore between these two motors, electric power conservation is 1.25 (ηmotor =95%)kW– 1.05 (ηmotor = 95
%) = 0.20 kW.

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 22
High-efficiency motors are more expensive but its operation saves energy. Saved energy is estimated by

Annual energy saving = Annual operation hours

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 23
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 24
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 25
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 26
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 27
 Energy Efficiency Standards

Thermal efficiency of residential furnaces and boilers is measured by annual fuel utilization efficiency
(AFUE).

Annual fuel utilization efficiency is the ratio of heat output of the furnace or boiler compared to the total
energy consumed by them over a typical year

An AFUE of 90 % means that 90 % of the energy in the fuel becomes heat for the home and the other 10 %
escapes up the chimney and elsewhere

Some of the minimum allowed AFUE ratings in the United States are as follows:
• Noncondensing fossil-fueled, warm-air furnace is 78 %.
• Fossil-fueled boiler is 80 %.
• Gas-fueled steam boiler is 75 %.

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 28
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 29
 Efficiency of Air Conditioner

• The energy efficiency ratio (EER) of a particular cooling device is the ratio of output cooling (in Btu/h)
to input electrical power (in Watts) at a given operating point

• The efficiency of air conditioners is often rated by the seasonal energy efficiency ratio (SEER). The
SEER rating of a unit is the cooling output in Btu during a typical cooling season divided by the total
electric energy input in watt-hours during the same period

• The coefficient of performance (COP) is an instantaneous measure (i.e., a measure of power divided
by power), whereas both EER and SEER are averaged over a duration of time

• The time duration considered is several hours of constant conditions for EER, and a full year of typical
meteorological and indoor conditions for SEER

• Typical EER for residential central cooling units = 0.875 × SEER

• A SEER of 13 is approximately equivalent to a COP of 3.43, which means that 3.43 units of heat energy
are removed from indoors per unit of work energy used to run the heat pump

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 30
• SEER rating more accurately reflects overall system efficiency on a seasonal basis and EER
reflects the system’s energy efficiency at peak day operations.

• Air conditioner sizes are often given as “tons” of cooling where 1 ton of cooling is being
equivalent to 12,000 Btu/h (3,500 W). This is approximately the power required to melt
one ton of ice in 24 h

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 31
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 32
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 33
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 34
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 35
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 36
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 37
 Energy Conservation While Driving

Some possible energy conservation steps are

• Speeding, rapid acceleration, and braking waste gas. It can lower your gas mileage by 33 % at highway speeds and by 5
% around town.
• Gas mileage usually decreases rapidly at speeds above 60 mph and observing the speed limit may lead to fuel saving of
7–23 %
• An extra 100 pounds in your vehicle could reduce the fuel efficiency by upto 2%
• Fixing a serious maintenance problem, such as a faulty oxygen sensor, can improve your mileage by as much as 40 %
• Gas mileage may be improved by up to 3.3 % by keeping your tires inflated to the proper pressure

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 38
 Energy Conservation in Electricity Distribution and Smart Grid
• A smart grid is a form of electricity network using digital technology
• Smart grid delivers electricity to consumers to control appliances at homes, optimize power flows, reduce
waste, and maximize the use of lowest-cost production resources
• A smart grid includes an intelligent monitoring system that keeps track of all electricity flowing in the system

• It also has the capability of integrating renewable electricity such as solar and wind.
• When power is least expensive the user can allow the smart grid to turn on selected home appliances such as
washing machines or some processes in a factory

• At peak times, it could turn off selected appliances to reduce demand

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 39
 Standby Power

• Standby power refers to the electricity consumed by many appliances when they are switched off or in standby
mode
• The typical power loss per appliance is low (from 1 to 25 W) but when multiplied by the billions of appliances
in houses and in commercial buildings, standby losses represent a significant fraction of total world electricity
use Standby power may account for consumption between 7 and 13 % of household power consumption
• Technical solutions to the problem of standby power exist in the form of a new generation of power
transformers that use only 100 mW in standby mode and thus can reduce standby consumption by up to 90 %
• Another solution is the ‘smart’ electronic switch that cuts power when there is no load and restores it
immediately when required

Sustainable Energy: Engineering Fundamentals and

© Serdar Celik 2023
Applications 40
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 41
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 42
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 43
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 44
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 45
 Part IV
Solutions for Sustainability

How do we develop sustainable

systems?

© Serdar Celik 2023

 Designing Sustainable Processes
and Products
The last word in ignorance is the man who says of an animal or
plant: “What good is it?” If the land mechanism as a whole is good,
then every part is good, whether we understand it or not. If the biota,
in the course of eons, has built something we like but do not
understand, then who but a fool would discard seemingly useless
parts? To keep every cog and wheel is the first precaution of
intelligent tinkering.

© Serdar Celik 2023

 Introduction
• Sustainability assessment methods are being used to guide
engineering decisions
– Product design
– Process design
– Supply chain management
– Corporate strategy

• These approaches go beyond traditional methods for enhancing profit

or efficiency of a single process
• Life cycle aspects are usually included

• We will cover techno-economic analysis, eco-efficiency, process and

product design

© Serdar Celik 2023

Sustainable Engineering: Principles and Practice
 Techno-Economic Analysis
• Total Cost (C) = Capital cost + Operating cost
• Capital cost: buildings, materials, land, etc.
• Operating cost: raw materials, labor, utilities,
depreciation, etc.

• Revenue (R): Earnings from selling products,

byproducts, carbon credits, etc.

• Gross profit:
• Net profit:

© Serdar Celik 2023

Sustainable Engineering: Principles and Practice
 Time Value of Money
• Simple interest:
• Compound interest:
• Present value of operating cost incurred every year

• Example: A car costs $20,000. Annual maintenance

cost is $1800. For a 5 year period with 8% interest,

© Serdar Celik 2023

Sustainable Engineering: Principles and Practice
 Profitability Metrics
• Return on investment – ratio of profit to capital cost

• Net Present Value – Present value of all cash flows

• A capital investment of a million dollars yields a

steady earnings stream of $50,000 every year as
net profit. Calculate the return on investment and
net present value. You may use an interest rate of
8%, and assume depreciation to be 10% per year.
• ROI = 5E+4/1E+6 = 5%
• NPV = -6.64E+5
© Serdar Celik 2023
Sustainable Engineering: Principles and Practice
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 52
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 53
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 54
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 55
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 56
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 57
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 58
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 59
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 60
 Eco-Efficiency
• “Creating more value with less impact”
– “Eco-efficiency is achieved by the delivery of competitively-
priced goods and services that satisfy human needs and
bring quality of life, while progressively reducing ecological
impacts and resource intensity throughout the life-cycle to a
level at least in line with the earth’s carrying capacity.”

• Three main objectives

– Reduce consumption of resources. Could be achieved by
enhancing recyclability and closing of material loops
– Reduce environmental impact. This involves reducing
emissions of pollutants and their impact
– Increase product or service value. Provide more benefits to
consumers through increasing product functionality,
flexibility and modularity

© Serdar Celik 2023

Sustainable Engineering: Principles and Practice
 Changes from Eco-Efficiency
• Re-engineer their processes by decreasing their resource intensity,
and pollution intensity

• Re-valorize their byproducts by efforts toward zero-waste or 100%

product

• Re-design their products to use more renewables, enhance

recyclability, improve durability, etc.

• Re-think their markets means that to improve their eco-efficiency,

companies will rethink their supply and demand

© Serdar Celik 2023

Sustainable Engineering: Principles and Practice
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 63
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 64
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 65
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 66
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 67
 Examples of Eco-Efficiency
• Traditional engineering approach: Enhance
efficiency of individual processes
– Process integration to enhance energy, water, solvent
efficiency
– Improve efficiency of solar photovoltaic panels
– Design more efficient buildings – high efficiency appliances,
low flow faucets, tankless water heaters, etc.
• Eco-efficiency approach: Enhance efficiency at life
cycle scale
– Increasingly popular in industry
– Choose product components that minimize carbon and other
footprints
– Example: http://www.unilever.com/sustainable-living/ourapproach/eco-
efficiencyinmanufacturing/performance/

© Serdar Celik 2023

Sustainable Engineering: Principles and Practice
 Examples of Eco-Efficiency

© Serdar Celik 2023

Sustainable Engineering: Principles and Practice
 Evolution of Engineering Design

© Serdar Celik 2023

Sustainable Engineering: Principles and Practice
 Multicriteria Decision Making
• Design for sustainability involves multiple objectives
– Profit (maximize)
– Life cycle impact (minimize)
– Societal benefits (maximize)
• Need to find solutions that balance the trade-offs
• Pareto Curve
– Represents trade-off
between objectives
– All solutions on Pareto
curve are optimal
– Choosing a solution
involves valuation

© Serdar Celik 2023

Sustainable Engineering: Principles and Practice
 Choosing the
Best Car
• Goals are price
and fuel economy

© Serdar Celik 2023

 Pareto Curve for Cars

© Serdar Celik 2023

Sustainable Engineering: Principles and Practice
 Heuristic Design
1. Inherent rather than circumstantial - Designers need to strive to ensure that all material
and energy inputs and outputs are as inherently nonhazardous as possible.
2. Prevention instead of treatment - It is better to prevent waste than to treat or clean up
waste after it is formed.
3. Design for separation - Separation and purification operations should be designed to
minimize energy consumption and materials use.
4. Maximize mass, energy, space, and time efficiency - Products, processes, and systems
should be designed to maximize mass, energy, space, and time efficiency.
5. Output-pulled versus input-pushed - Products, processes, and systems should be “output
pulled” rather than “input pushed” through the use of energy and materials.
6. Conserve complexity - Embedded entropy and complexity must be viewed as an
investment when making design choices on recycle, reuse, or beneficial disposition.

© Serdar Celik 2023

Sustainable Engineering: Principles and Practice
 Heuristic Design
7. Durability rather than immortality - Targeted durability, not immortality, should be a
design goal.
8. Meet need, minimize excess - Design for unnecessary capacity or capability (e.g., “one
size fits all”) solutions should be considered a design flaw.
9. Minimize material diversity - Material diversity in multicomponent products should be
minimized to promote disassembly and value retention.
10. Integrate local material and energy flows - Design of products, processes, and systems
must include integration and interconnectivity with available energy and materials flows
11. Design for commercial “afterlife” - Products, processes, and systems should be designed
for performance in a commercial “afterlife”.
12. Renewable rather than depleting - Material and energy inputs should be renewable
rather than depleting

© Serdar Celik 2023

Sustainable Engineering: Principles and Practice
 Summary
• Techno-economic analysis considers economic
sustainability
• Eco-efficiency combines aspects of environmental
and economic sustainability
• Engineering design has evolved from ignoring the
environment to considering life cycle impacts
• Sustainable design problems involve multiple
objectives and constraints

© Serdar Celik 2023

Sustainable Engineering: Principles and Practice
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 85
 Sustainable Energy: Engineering Fundamentals and
© Serdar Celik 2023
Applications 86