Contents

Introduction ............................................................................................................................................ 1
Background and Justifications ............................................................................................................ 1
Motivation........................................................................................................................................... 3
Literature Review ................................................................................. Error! Bookmark not defined.
Statement of the Problem .................................................................................................................. 3
Objectives ........................................................................................................................................... 5
General Objective ........................................................................................................................... 5
Specific Objectives .......................................................................................................................... 5
Methodology....................................................................................................................................... 5
Scope of the Project ............................................................................................................................ 5
Literature Study on Energy Saving Technologies ................................................................................ 6
Energy Saving Technologies in the United States of America ........................................................ 6
Sources of Energy in Developing Countries .................................................................................... 7
Prepared By:
Migration from the use of Biomass fuel to Electrical Mogogo and Stoves..................................... 8
1. Tirffneh Yimer
2. Yaecob9Girmay
2.4 Electric Stove and Mogogo ...........................................................................................................
3. Redae Kassa
Electric Megogo Demand in Ethiopia ............................................................................................ 10
4. Gebrehiwot
Design and Implementation.................................................................................................................. 12
Gebemedhin
Mechanical design and modelling of Injera baking Mogogo ............................................................ 12
Design of baking clay plate ........................................................................................................... 12
Design of baking clay plate cover.................................................................................................. 13
Design of Mogogo supporting legs ............................................................................................... 13
ENERGY SAVING APPLICATIONS
Electrical design ................................................................................................................................ 13
Equivalent circuit of the electrical heating element of Mogogo ..................................................
June, 2022 13
Stove design ........................................................................................................................................ 1
Design of Automatic Lamp Control System ........................................................................................ 2
Circuit Diagram of the automatic lamp controller .......................................................................... 2
Principle of operation the automatic lamp controller .................................................................... 3
Results and Discussion ............................................................................................................................ 3
Energy required for injera baking ....................................................................................................... 3
Prototype Mogogo .............................................................................................................................. 5
Experiment/Measurements ............................................................................................................ 5
Automatic Light controller switch....................................................................................................... 6
Conclusion and Future works ................................................................................................................. 8
References ............................................................................................... Error! Bookmark not defined.

Chapter one: Introduction

This chapter presents the background, motivation, problem statement, objectives and methodology
of the project. An overview of background and justifications are also discussed. Moreover, some
previously related works on energy saving are also discussed.

Background and Justifications

Energy plays a vital role in a nations development and wellbeing. Electric energy drives economic and
social development by increasing productivity, incomes, and employment. It also reduces citizens’
workloads and facilitates the availability of higher-quality & lower-priced local products. Countries
such as the USA states the deployment of energy efficiency technologies is the nearest-term and
lowest-cost option for moderating the nation’s demand for energy. [1]

The 2017 energy consumption data from Ethiopian Electric Utility shows that the Energy consumption
share of the Northern (Mekelle) District is the highest next to the districts in Addis Ababa and its
surroundings.

Figure 1 : Energy consumption by districts [2017 data]

When we see the 2019 energy consumption data from EEU by region, the energy consumption per
capita is high in Tigray.

1
 Figure 2 : Energy consumption share of regions [2019 data]

The customers in Tigray can be clustered as domestic, commercial, industrial low voltage, industrial
medium voltage, industrial high voltage and street lighting. The diversification of the energy
consumption in Tigray region justifies the largest proportion of the energy consumed in the region is
by households. Moreover, the energy consumption of commercial customers is dominated by hotels,
restaurants, universities and others that use Mogogos and stoves.

Figure 3: share of energy consumption in Tigray by category [2018 data]

2
There are different energy inefficient devices and usage techniques in Tigray. To mention some, the
locally manufactured cooking appliances such as Mogogos and stoves consume the largest share of
the electric energy in households, hotels, universities, restaurants, Injera sellers, etc. When we take
the street lighting and office lighting system, most of it is manually operated. As a result, we can
observe a street light ON during day time and sometimes they are OFF during night. Therefore, if we
incorporate an automatic switch that can control the street lighting and office lighting, we will save a
significant amount of energy.

The Electric Mogogo are rated at 3.7 to 4.0 kW. A typical household is assumed to have a power
demand of 7 kW. Therefore, Mogogos are estimated to constitute about 57 % of the power demand
of a typical residential household. It is customary to see the dimming of light bulbs when Mogogo is
turned ON. Electric Mogogo and stoves contribute to the bulk of the electric power demand and
consumption of a typical residential household and the nation.

Motivation
In Tigray, due to the ever-increasing demand for electricity and the lack of energy generation station
(only Tekeze with a lot of problems) as well as the shortage of fire wood and biomass energy saving
application has attracted a growing research interest.
Nowadays, the scholars of Tigray are trying to investigate a smart way of utilizing the electricity
available. Thus, it needs depth research in the area of energy saving application. This motivates us to
work on this research project.
Moreover, we are motivated to do this research in order to; reduce capital investment in energy
generation, transmission and distribution infrastructure; reduce customers’ expenses by reducing
energy bills; enhance consumer welfare by incorporating safety measures in the energy saving
devices; empower customers of the electric utility to include Energy Efficiency in their choice and
decision; strengthen competitive markets among producers of local stoves/Mogogos or other local
solutions; meet climate-change goals; avert urban/regional pollution.

Statement of the Problem

The largest share of the electric energy generated in Tigray is consumed by domestic customers. In
Tigray, there are devices that demands high electrical energy such as Mogogo, locally manufactured
stoves, street lighting, government offices, universities, etc. As the former two devices, Mogogo and
local stoves, are manufactured locally little effort are done on improving the efficiency of the devices.
In addition, the street lights and offices lighting consume significantly large amount of electric energy
as they remain ON during day time. This is resulted from the reason that many of these street lights
and offices lighting are operated manually.

3
There is no actual data on the number of electrical Injera Mogogo in Tigray. The EEU data shows that
there were estimated 2,324,706 customers in Tigray in 2018 out of which 1,860,000 are domestic
customers. Studies shows that 95 to 97% of the domestic customers are residential households and
3 to 5% belong to the non-commercial premises. The customers that use Injera Mogogo and locally
manufactured stoves are households, hotels, restaurants, universities, Injera sellers, etc. Considering
only the active customers and the ones that consume larger power we assume that the customers
who use Mogogo and stove are believed to constitute more than 25% of the total number of
customers. Therefore, the number of customers that uses stoves and Mogogos are 0.25*2,324,706 =
580,000. This number is expected to be higher as the number of stoves and Mogogos in some
households, hotels, restaurants, universities, Injera sellers, etc are more than one per entity.

The installed power demand of a typical 60 cm Mogogo is tested to be 4 kW, 58 cm requires 3.8 kW
and that of 56 cm requires 3.6 kW. Let’s take 3.8 kW as an average steady state energy demand of a
Mogogo. Thus, the total power demand of all Mogogos in Tigray is 580,000*3.8 kW=2,208 MW. The
total annual energy consumption can be calculated by assuming Injera is baked every four days and 2
hours baking time; 580,000*3.8*365/4*1.5=302 GWh. Similarly, more than 10% of the domestic
customers uses the locally manufactured stoves and the power demand of one stove top is tested to
range from 1kW to 1.4 kW so an average of 1.2 kW is considered per one cook top. Let’s assume the
proportion of single cook plate to double cook top to be 70:30 (40,600 single cook top and 17,400
double cook top). The total number of cook tops is summed up to be 58,000. Hence, the total energy
demand is 58,000*1.2=69.6 MW. If we assume an average 2 hours per day cooking time the annual
energy consumption is; 58,000*1.2*2*365=50 GWh. Therefore, the total energy consumption of both
the stoves and Mogogs can be summed up to be 352 GWh. For the sake of comparison, the annual
energy generation capacity of Tekeze hydro power plant is 981 GWh.

Some studies indicate the efficiency of the Mogogo can be improved by about 37% and that of the
locally manufactured stoves by more than 19% and further improvements are possible in both devices.
Thus we can be able to save a total power of at least 142 GWh per year ((0.37*208) + (0.19*342)).

The core problem of existing electric Mogogos and local stoves is that it is energy inefficient due to
high heat load; heat losses at the bottom of the clay plate; heat losses at the side of the clay plate;
heat losses at the lifting cover; heat losses due to the makeup and production of the clay plate; heat
loss during overheating of the Mogogo; absence of standard on the sizes of Mogogo; electrical heating
elements (Resistors) and the method of installation; and there is limited research and innovation.

Moreover, street lights in Tigray consume 5.4 GWh of electrical energy. However, it is a usual
experience that we see some street lights ON during day time as mostly it is manually operated and if

4
the operator is failed to turn it OFF it stays for the whole day. This power loss can be avoided by
incorporating an automatic switch that can check the availability of sun light and control the status of
the street lights. Thus, significant amount of electric power will be saved.

Objectives
General Objective
The general objective of the project is energy savings from efficiency improvement measures taken
place in different materials and sectors will be studied.

Specific Objectives
 study the energy consumed by Mogogs, stoves and street lighting in Tigray
 study the amount of energy that can be possibly saved in baking Injera, cooking using stoves
and street lights
 design and develop a prototype energy saving Mogogo, stove and street light controller
 study awareness creation models among government officials, Mogogo/Stove producers and
energy consumers on energy saving issues.

Methodology
To achieve the general and specific objectives mentioned above the methodology to be followed
should be clearly stated. The first task to meet the objectives is studying about the energy utilization
by conducting a literature review on energy saving applications, like Mogogo, stoves and others.
Measurements are also done on different Mogogos, stoves and street lighting. This is followed by
design and development of a prototype of energy efficient Mogogo and stove. Moreover, studies to
develop performance and product standards for local stoves and Mogogos, awareness creation
methods among government officials, producers of local stoves and consumers on the subject of
energy saving from efficiency improvement are also done. Besides, we have designed and
implemented a prototype automatic lamp controller that can be used to save energy from street
lighting and offices lighting.

Scope of the Project

In this research project energy saving of three energy efficient devices namely Mogog, stoves and
street lighting are discussed. Analysis are also made on the amount of energy saved based on
hardware model, software and other analytical techniques.

5
Chapter Two: Literature Study on Energy Saving Technologies
Energy Saving Technologies in the United States of America
United States of America (USA) is considering the development and deployment of existing energy
saving technologies in order to address the demands of future energy in the country. The potential
energy savings available from the accelerated deployment of existing energy efficiency technologies
in buildings, transportation, and industrial sectors could be more than US Energy Information
Administration’s (EIA’s) projected increases in energy consumption in 2030 G.C. According to the study
by committee on America's energy future, deploying of cost-effective energy saving applications in
buildings alone could avoid constructing new electricity-generating plants. However, it does not
include increased use of electricity in other sectors. The savings could reduce energy use by about 15%
in 2020 G.C, and by about 30% in 2030 G.C in reference to the projection of EIA. Even more energy
savings is possible if more aggressive policies and incentives are adopted. Most of these energy
efficiency technologies are cost-effective now and are likely to continue to be competitive with any
future energy supply options; moreover, additional new energy efficiency technologies continue to
emerge in the nearest-term and lowest-cost option for extending domestic supplies of energy. Many
energy efficiency savings can be obtained almost immediately by deploying currently available
technologies. In contrast, constructing and providing new energy supplies typically takes many years.
Moreover, energy efficiency has broader societal benefits beyond saving energy. Society is giving more
attention to the ecosystem. Hence, efficiency involves few emissions of CO2, endangers no species,
and does not destroy scenic views.

Huge energy efficiency savings, in 2007 G.C up to 70% of electricity consumption which is
approximately equal to 2700 Tera Watt hour (TWh) out of 4000 TWh in total can be realized in the
buildings sector. Using energy efficiency technologies in residential and commercial buildings, for
space heating and cooling, water heating, lighting, computing, and other uses could save about 840
TWh per year by 2020 G.C (see Figure 4: Estimates of potential energy savings in commercial and
residential buildings in 2020 and 2030 (relative to 2007 G.C) compared to projected delivered
electricity.). This exceeds the EIA’s projected increase in electricity demand of about 500 TWh for
residential and commercial buildings by the same year (EIA, 2008). Further continuous improvements
in building efficiency could save about 1300 TWh of electricity per year by 2030 G.C (see Figure 4),
which also exceeds the EIA-projected reference scenario increase in electricity demand of about 900
TWh per year in the same year. In addition, improvements in building efficiency could save 2.4 quads
of natural gas annually by 2020 G.C and 3 quads of natural gas annually by 2030 G.C. There are many
energy saving applications worth investing on buildings. For example, an approximate 80% increase in
energy efficiency translating to nearly a 12% decrease in overall electricity use in buildings could be

6
realized immediately by replacing incandescent lamps with compact fluorescent lamps (CFL) or light-
emitting diodes. Furthermore, energy savings between 10% and 80% could be realized by replacing
older models of air conditioners, refrigerators, freezers, furnaces, and hot water heaters with new and
efficient models. Such replacements would not occur as quickly as replacing lamps because it is usually
cost-effective to replace appliances only when they near the end of their service lives. Buildings last
decades, so the energy savings benefits of new buildings will take decades to see. [1]

Figure 4: Estimates of potential energy savings in commercial and residential buildings in 2020 and 2030 (relative to 2007
G.C) compared to projected delivered electricity. [1]

Sources of Energy in Developing Countries

People in developing countries use woods, animal dung and other biomass resources as the means of
energy for baking and cooking. Research findings indicate that around 800 million people who use
biomass as their main source of energy are exposed to critical health conditions and even deaths [2].
African countries account for 71.5% of biomass use as their primary energy source, in some countries
of the Sub-Saharan region, the figure shoots to 90% [3]. Some studies predict that if people use mainly
this source of energy, by 2030 more than one billion Africans will be exposed to sever health conditions
[4]. During this period, the world’s population is estimated to reach 8.2 billion; in which 90% of the
population and 90% energy demand will come from developing countries [5]. Use of clean energy has
been set for Millennium Development Goals (MDGs); however, energy production equivalent to 715.4
million metric tons of oil is not enough to meet the demands [6]. Even though there is huge potential

7
of clean energy in the continent, it remains underutilized due to lack of technical, economic, political
and social reasons [7].

Like those of developing countries, the people of Tigray use wood, animal dungs and many other
biomass resources as the primary source of energy for baking and cooking. In addition, our rural
community lives far from the national grid where the aforementioned energy resources are the only
alternative ones. On the other hand, large part of the urban communities with access to electricity still
depend on the rural supply for wood, charcoal and animal dungs. A research paper presented here
[8], ascertains this fact of dependency of urban on the age old traditional energy harnessing
mechanisms that was started many thousands of years ago. Notwithstanding cheaper electricity,
many urban in habitants persist using traditional energy sources. The higher price and huge demand
for biomass in urban is one of the main reasons for deforestation and degradation. Unless government
and other stakeholders’ efforts are intensified to create awareness and provide options for efficient
energy saving applications, this will adversely affect the climate and the environment. Let’s see a
bigger picture, compared to Tigrai, Ethiopia has enormous potential for developing various energy
resources, the per capita energy consumption remains to be among the lowest in the world [8]. In
most households of Ethiopia, the energy demand for baking injera is largely met with biomass such
as, wood, agricultural residue and animal dung. Injera baking is the most energy intensive process that
requires 2000C - 2500C on the surface plate of Mogogo [4]. Reports indicate that cooking and baking
account for over 50% of the generated electrical energy in Ethiopia. Introducing a new alternative
energy source for baking injera should be considered as an opportunity and important aspect from
environmental and economic point of view. Women in villages and in some urban communities are
relieved from economic burdens associated with firewood gathering or purchasing if these
alternatives are implemented fast.

Migration from the use of Biomass fuel to Electrical Mogogo and Stoves
For the purpose of baking and cooking, people waste their considerably large and precious time in
search of woods. This has an adverse effect on educating these people rather than modernizing and
living a better life.

According to a study on the use of energy by Ministry of Water, Irrigation & Electricity for the year
20008/2009 EC (2014/2015 GC), 98.30 % household energy use was almost entirely from biomass,
consumption of electricity and petroleum products together for household accounted for 1.70% only.

In the last decade, there have been different phases of rural electrification works in Ethiopia by the
government for the betterment of utilization of energy. Additionally, the scarcity and increased price
of firewood and the relatively cheaper electrical energy tariff creates favorable conditions for

8
migration from using biomass fuel to the use of electric Mogogo and Stoves. Hence, it is projected that
many Mogogo and Stoves will be added to the existing ones at a faster rate. This further creates more
demand for electric Mogogo and Stoves, thereby the demand for power and energy consumption will
be increased [9] and [10]. However, utilization of energy is still poor because the locally made devices
for baking and cooking are not energy efficient [9].

Figure 5: Schematic representation of the energy ladder (Leach, 1992), (Netsanet Adgeh Ejigu, 2014)

Electric Stove and Mogogo

An electric stove is an integrated electrical heating device to cook and bake. Electric stoves may have
single or multiple cook tops and be controlled by a fixed or rotary switch with a finite or infinite
number of positions, each of which engages a different combination of electric resistances and hence
a different heating power. Some may have a thermostat to switch power and to control the average
heating effect of the elements [10].

(a) (b) (c)

Figure 6: (a) local stove (b) Iron hot plates, imported (c) Spiral hollow steel tube, imported [10].

9
An Electric Mogogo is made from steel or Aluminum sheet metal framework having a conical shaped
lifting cover, short cylindrical enclosure (body), clay plate, an electric heating element, heat insulator
and a support stand. The clay plate of electric Mogogo is made either as a single or double, circular
plate having diameter ranging from 40cm to 60cm and thickness of 2.3cm to 2.5cm. Clay plate having
58cm diameter is the most common. The difference between the single and double clay plate type is
the method of placing the heating element and clay plate support mechanism. Electrical heating
element, resistance, is placed in a groove made in a helical fashion at the bottom of the single clay
plate type and sealed with Gypsum material whereas it is kept in between the upper and lower clay
plates in the case of the double clay type. The single plate type is the more common of the two. The
40cm diameter single clay type is mostly made for the Ethiopian Diaspora [9].

Due to the low energy efficiency of the existing electric Mogogo, there is a huge electrical energy
wastage and power demand in the country. Based on the tests made, the efficiency of Electric
Mogogos could be improved by about 37% and further improvements are possible. This indicates that
majority of the conventional Mogogos have low efficiency. However, the demand for the product is
growing at a high rate due to the rapid economic growth, the shortage of firewood and biomass, and
the different electrification programs underway. The number of producers and the production rate is
high. This justifies urgent need for electric energy standardizing and labeling of electric Mogogo [9].

Electric Megogo Demand in Ethiopia

Energy usage for baking of injera accounts for over 50% of the power used in a given household. The
existing Mogogo design suffers from many shortfalls. Key ones are:
 The high resistance, inadequately sized electric wiring, and incorrectly adjusted combustion
element;
 Use of poor construction materials;
 Poor insulation: dissipation of energy during the baking session is said to roughly range from
40 to 50 percent;
 Lack of temperature control device such as a thermostat, encouraging loss of heat; and
overall, sub-optimal/poor and inefficient design and workmanship.
 The number of electric Mogogo in Addis Ababa in the year 2010 was estimated to be 400,000
rated at 3.5 Kw.
 Existing baking and cooking energy consumption represent about 100 MW of additional peak
load.
 Daily baking‘s power load becomes coincident with peak load requirements, thereby
overloading the distribution system.

10
  Use of energy efficiency measures will help lower operating costs, add to system‘s operational
reliability, and potentially lower power transmission and distribution investment needs.
 Manufacturing of low cost energy efficient Mogogo is of paramount importance to cost-
effectively manage peak load demand and reduce daily blackouts.
 Demand reduction and energy conservation programs are considered an excellent tool to
economically add to power supply at low cost by saving energy.
 Given the urgent need to develop energy efficient, cost effective Mogogo the existing design
wastes over 35% of energy as heat.

Government should provide incentives to the few, currently fledgling, start-up entrepreneurs in this
area. To prevent their crash and burn, such incentives need to be provided in a well-planned, well-
monitored, fashion. Few suggested ones are: direct financial support, preferably cost-shared; tax
credits; and enabling policy support such as marketing campaigns and development of pilots.

11
Chapter Three: Design and Implementation
Mechanical design and modelling of Injera baking Mogogo
The mechanical part of the baking clay plate has a huge contribution in the low energy
efficiency. Therefore, a careful design and selection of materials should be considered in the
mechanical system.
Design of baking clay plate
The existing Electric Mogogo technology is believed to be in the market for over 40 years. Its
performance efficiency is very low and the product has not been standardized so far. The Electric
Mogogo is made from steel or Aluminium sheet frame having a conical shaped lifting cover, short
cylindrical enclosure (body), clay plate, an electric heating element (Resistor), heat insulator and a
support stand. The clay plate of the Mogogo is made either as a single or double, circular plate having
diameter ranging from 40 to 60 cm diameter and thickness of 0.8 to 2 cm. Clay plate having 58 cm
diameter is the most common. The difference between the single and double clay plate type is the
method of placing the heating element and clay plate support mechanism. Electrical heating element
(resistance) is placed in a groove made in a helical fashion at the bottom of the single clay plate type
and sealed with Gypsum material whereas it is kept in between the upper and lower clay plates in the
case of the double clay type. The single plate type is the more common of the two.

(a) (b) (c)

Figure 7: a) Back side of clay plate with groove, b) Sealed with Gypsum and c) Assembled Mogogo
The specifications of the Mogogo plate material shall be as follows; [11]
Density=2.71 g/cm3
Thermal conductivity=217.774 w/m.0k
Yield strength=151.68mpa
Tensile strength=165.47mpa
Specific heat=0.9 j/g.℃
Thickness baking pan =0.8-2cm
radius of the plate= 20-30cm
The mass of the pan is calculated as follows
= ∗

12
Therefore, the mass of the plate can vary from 2.75 to 6.1 kg.

Design of baking clay plate cover

Mogogo cover is a cone shaped material used to protect heat loss from Injera during baking. It can be
manufactured from aluminium or metal sheet with the following dimensions. Diameter of cover pan
can range from 60-63 cm and height of the cover pan 13-15 cm.

Figure 8: Baking clay plate cover (3D using sold work software) [11]

Design of Mogogo supporting legs

To carry the whole weight of the Mogogo, four supporting legs can be welded to the supporting ring.
The material should be Stainless steel with thickness of 25× 25 mm.

Figure 9: Mogogo supporting legs (3D using sold work software)

Electrical design
Equivalent circuit of the electrical heating element of Mogogo
The basic electrical elements available in
the traditional Mogogo are the voltage source, electrical wires, the switch and resistor. The equivalent
circuit of a system is a circuit representation of the equations describing the behaviour or performance
of the system. Therefore, the equivalent circuit for a Mogogo is:

Figure 10: Equivalent Circuit of a Mogogo

Two pieces of the 0.9 mm diameter electrical heating element (resistor) connected in parallel are
commonly used per Mogogo for sizes from 56 to 60 Cm diameter. Based on the survey made, many
of the locally produced responded that they use the 0.9 mm resistor type. However, the resistance
measurements on their products during the survey made revealed that the resistance values differ

13
significantly. Different length and resistance values are supplied by various suppliers. Eg. For 1x 0.9mm
type, resistance values are like 22.9 Ω, 23.1 Ω, 26 Ω, 28 Ω. Resistances are mostly wound locally and
the value per resistor depends on the length and diameter winded. As electrical power equals the
square of voltage divided by resistance (P = /R), slight change in the value of resistance changes the
power demand. Hence, the electrical Mogogos currently produced do not have equal and uniform
power rating, even within the products of the same producer. Therefore, the resistance of a given
Mogogo can vary from 11.45 Ω to 14 Ω. As a result, the power demand of the Mogogo varies from
3,400 watts to 4,200 watts. And the current rating of the switch that is used in Mogogos shall be 25 A
as the current can vary from 16 A to 19 A.

a. b.
Figure 11: a. Heating element (Resistor) b. 25 A Switch
Most of the producers place the resistor bought from the market directly into the clay plate without
having the knowledge of how much power the device will be rated at. Furthermore, producers fix the
power rating of their products based on the capacity of the electric metering device.
It has also been observed that at some producers ‘resistance values were very low. This occurred
due to shortening of resistances in order to get higher power on the Mogogos so that the Mogogo
bakes fast. Such practices affect power demand.

Stove design
Similarly, in the stoves the resistances used can be 0.6, 0.7, 0.8 or 0.9 mm2, the diameter of the cooking
plate can vary from 18-40 cm. One resistor is used per stove. The resistance can range from 22 Ω to
50 Ω. Therefore, the energy consumption of a single stove varies from 970 watts to 2,200 watts. The
current rating of the appliances also ranges from 4 A-10 A. Apart from these variations the metal works
that are used to support the appliance have differences.

Figure 12: prototype stove

1
Design of Automatic Lamp Control System
The main components of the system are LDR, TRIAC and Lamp. The block diagram depicted below
organizes all these components.

Figure 13: complete block diagram of the Lamp Control system

A proto type automatic street lighting system is prepared and tested; this system has a rating of 220,
60 W. The design of this system is

Figure 14: System flow chart

The process of controlling the lamp is as follows;

Figure 15: How the lamp controller works

Circuit Diagram of the automatic lamp controller

The circuit diagram of an automatic lamp controller is given below:

2
 Figure 16: Circuit diagram of the automatic lamp controller

Principle of operation the automatic lamp controller

The main application of this automatic lamp control is in street lights and office lights. The automatic
lamp controller has a photoconductive device whose resistance changes proportional to the extent of
illumination, which switches ON or OFF the lamp with the use of transistor as a switch.

Results and Discussion

Energy required for injera baking
Baking injera requires intensive energy and this energy can be defined as the energy necessary to raise
the batter to a particular temperature, and evaporate the amount of water that is to be lost during
the baking process. To measure the energy utilized in baking injera, the initial mass of batter, and the
total amount of injera produced from this batter were measured. Thus, the mass of water vapor can
be obtained by reducing the mass of the injera produced from the initial mass of batter. It is assumed
that the energy utilized in baking the injera is the energy required in raising the temperature of the
batter from room temperature to the boiling point of water which is called sensible heat, plus the
energy required to evaporate water which is called latent heat. It is also assumed that the heat
capacity of injera batter is

the same as that of water in order to calculate the energy required to raise the batter temperature to
boiling point. Therefore, the utilized energy is:

= ( − )+( − )ℎ (2.1)

Where:

− is the energy utilized

− is the mass of the batter expected for one injera

3
 − is the boiling temperature of water in Mekelle

− is the room temperature in the baking pan test room

− is the heat capacity of water

− is the mass of the injera produced

ℎ −is the heat of vaporization of water (ℎ ) in

Measured input data:

 the mass of the batter expected for one injera= 450g-680g

 the boiling temperature of water in Mekelle = 92℃
 the room temperature in the baking pan test room = 23 ℃

 the heat capacity of water = 4.187kJ/kg.k

 the mass of injera produced = 350g-500g
 the heat of vaporization of water ℎ = 2260kJ/kg
Therefore, the energy utilized based on the given measured data is calculated as follows.

= 0.45kg*4.187kJ/kg.k(92-23)k + (0.45-0.35)kg*2260kJ/kg
= minimum 356 kJ and the maximum is 603 kJ

Average energy required can be taken to be 480 kJ. The time taken for baking of one injera is about
2.5 to 4 minutes. Taking 3 minutes as an average baking time, the electric power required for baking
one injera is calculated as follow.

= ∆

Where:

P- is the average power required for baking one injera

∆t = 3 ∗ 60 = 180
480
=
180
P=2.6 kW
However, the actual power that is required for baking Injera differs for different batter and
size. Therefore, survey is made on different houses.

4
Prototype Mogogo
We have studied the main causes of the energy loss in the Mogogs and these are large heat load, heat
loss on different sides, overheating, absence of standards, etc. Therefore, we have prepared a
prototype energy saving Mogogo on which we are conducting our different experiments and further
improvements are believed possible.

Experiment/Measurements

The survey is done on different Mogogos and stoves shows that there is a variation on the electrical
rating of the Mogogos under test. The following table can summarize the measurements done on 10
Mogogos, including the energy saving Mogogo. These Measurements were done on Mogogos from
different producers, types, injera bakers, sizes, power feeder lines, etc.

If we make comparison among three different Mogogos from the measurements, it can be
summerized in tabular form as below

5
Therefore, as it is depicted in the table above the energy conversion efficiency is too low and
improvements on the Mogogo can be made that can significantly boost the efficiency.

Automatic Light controller switch

The system works based on the amount of the light that is falling on surface of the Light dependent
resistor (LDR). If the light is above the threshold the lamp will stay off, if the light is not enough and if
the darkness is slight the lamp will start to glow dimly and if the darkness is full the lamp will be ON
with full brightness. And the result of the prototype prepared looks like;

a) when there is enough light b) when there is some darkness c) when there is full darkness

Barriers to adoption of Energy Saving Measures

Why don’t government, consumers and businesses take greater advantage of cost-effective energy
efficiency opportunities? If so much energy can be saved, why doesn’t everyone do it, especially when
the cost savings over time tend to well outweigh the initial costs?

The answer is complex, as there is no one reason for this seeming behaviour gap. Studies identify
factors—commonly called barriers—that impede the full uptake of energy efficiency technologies

6
and measures. They fall into several categories, but the following examples illustrate how some of
them affect decisions:

 Cost savings may not be the only factor influencing a decision to invest in an energy
efficiency measure. For example, consumers purchase vehicles based on many factors, such
as size, performance, and interior space, in addition to fuel economy. In reality, fuel
economy may not come into the picture at all.
 Although energy and cost savings might be achievable with only a low first cost (investment),
such savings may be a small-enough part of the family or company budget that they are not
really relevant to economic decisions.
 The up-front financial investment might be small, but substantial investments of time and
effort may be required to find and study information about potential energy-saving
technologies, measures, and actions.
 It is well established that purchasers tend to focus much more on first costs than on life-cycle
costs when making investments. This behavior is no different when it comes to energy
efficiency. There is also the phenomenon of risk aversion—new products may be unfamiliar
or not work as expected. The default behavior is often simply the status quo. Knowing this,
producers may never design and develop energy-efficient products.
 Some of the behavior gap can be attributed to economic structural issues. For example,
landlords of rental residential buildings are not motivated to pay for technologies that are
more efficient when their tenants pay the utility bills. And builders whose incentive is to
minimize the cost of new homes may not offer highly efficient appliances that increase
purchase prices but save buyers money over time.
 Other factors may involve retailers of equipment and appliances. If there is low demand for
efficient products, retailers may not stock them. Even purchasers who might be motivated to
search elsewhere for an efficient product may have to deal with limited choices in the event
of an emergency purchase, such as when a refrigerator fails.
 Other reasons for the behavior gap are the subject of much social science research. They
involve factors such as habits in purchasing or use, which can be very difficult to change. Some
apparent consumer preferences—typically learned from parents, neighbors, and friends—
may change very slowly, if at all.
 Energy-savings investments by businesses and industries are not always seen as beneficial. If
energy accounts for only a small part of total costs, or if the available capital is limited, other
investments may be preferred—e.g., in reducing other costs, improving products, or

7
 developing new ones. If the consequences of a new-product or production-method failure are
large, this in itself can maintain the status quo.
 Firms may not be aware of the potential savings achievable by replacing equipment, such as
older motors, with more efficient or variable-speed versions. When motors, large or small, are
used throughout a facility, the savings from upgrading them can be substantial.
 Energy efficiency investments by companies are made in the context of complex business
cultures. “Champions,” or commitment at the highest levels, may be required.

Market-transformation Strategy and Energy saving policy recommendation

Conclusion and Future works

References

[1] C. o. A. E. Future, N. A. o. Sciences, N. A. o. Engineering and N. R. Council, America's Energy

Future: Technology and Transformation, Washington D.C.: The National Academies Press,
2009.

[2] T. W. Bank, world development indicators, 2013.

[3] USAID, Environmental Guidelines for Small-Scale Activities in Africa (EGSSAA), 2009.

[4] E. O. E. AdeolaIjeoma Eleri, Rethinking biomass energy in Sub-Sahara Africa, 2009.

[5] IMARA, A different kind of power struggle.” Imara Sub Saharan Africa Energy Sector Report,
2012.

[6] E. p. i. Africa, The OPEC Fund for International Development (OFID) Nigeria;, 2008.

[7] F. Z. Nicolai S, Market barriers to clean cooking fuels in Sub-Saharan Africa, Stockholm
environment institute, 2008.

[8] A. Ayalew, Transient Heat Transfer Analysis of Injera Baking Pan (“Mittad”) by Finite Element
Method, Master Thesis, Addis Ababa University, Addis Ababa Institute of Technology, Ethiopia,
2009.

[9] E. E. A. a. D. E. Engineering, Energy Efficiency Standards and Labeling Project Document for
Electric Injera Mitad, Addis Ababa, Ethiopia, May 2015.

[10] E. E. A. a. D. E. Engineering, Ethiopian Energy Authority Project document on locally

manufactured electric stoves Energy Efficiency Standards and Labeling, Addis Ababa, Ethiopia,
March 2017.

[11] W. G. a. W. B. Weldu Tesfay, Design and Modelling of Solar Powered Injera Baking Mitad for
Indoor Use, Mekelle: Mekelle University, 2016.

8
[12] EEA, “Annex 2 : EEU customer count data for 2008 EFY,” in Locally manufactured electric stoves
energy efficiency standards and labeling, Addis Ababa, 2017, p. 134.