Energy Management in Agriculture is a course which explains how energy can be managed and conserved in order to use it efficiently without harming the environment in the context of Agriculture.

1. Lecturer: Jean de Dieu IYAKAREMYE, Msc.
E-mail:iyakjdd@gmail.com
UR/College of Agriculture, Animal Sciences
and Veterinary Medecine

2.  Energy is the driver of growth
 Energy provides better living conditions to its
citizens
 Its growth has to be balanced and sustainable
 energy management and energy conservation
measures are: eco-friendly, minimum
pollution and carbon emission

3.  The fundamental goal of energy management
is: produce goods, provide services with the
least cost and the least environment effect
 The definition of energy management is:“The
judicious and effective use of energy to
maximise profits (minimise costs) and
enhance competitive positions”.

4. Objectives:
 To achieve and maintain optimum energy
procurement and utilization, throughout the
organization
 To minimize energy costs / waste without
affecting production, comfort and quality. To
minimize the environmental effects.

5.  Energy in any form is a scarce commodity and
most valuable resource
 As by prediction showing that the life
expectancy of world population will increase
so energy could, in the future, be in short
supply

6. There are two main sources of energy. They are conventional
and non conventional sources of energy.
i) Conventional sources of energy :- are wood, flowing water and
fossil fuels (coal, petroleum, natural gas).
ii) Non conventional sources of energy :- are solar energy, wind
energy, biomass energy, ocean energy (tidal energy, wave
energy,
ocean thermal energy), geothermal energy, nuclear energy etc.
 Some sources of energy are renewable like sun, wind, flowing
water, ocean, wood, biomass etc.
 Some sources of energy are non renewable like coal,
petroleum and natural gas.

7. a) Fossil fuels :- are fuels formed inside the earth from the
remains of plants and animals after millions of years. The
fossil fuels are coal, petroleum and natural gas. Fossil
fuels are non renewable sources of energy so they
should be conserved and used judiciously.
Disadvantages of fossil fuels :-
i) Burning of fossil fuels release gases and harmful particles
which causes air pollution.
ii) Burning of fossil fuels release acidic oxides of sulphur and
nitrogen which causes acid rain which is harmful for living
organisms, affects soil and water, causes damage to buildings,
corrosion of metals etc.
iii) Burning of fossil fuels release a large amount of carbon
dioxide gas which increases the temperature of the atmosphere
and causes global warming (green house effect).

9. b) Thermal power plants :
 In thermal power plants the heat energy produced
by burning fossil fuels like coal, petroleum or
natural gas is used to heat water and change it
into steam which rotates the turbines of
generators to produce electricity.
c) Hydro power plants :
 In hydro power plants water from rivers are stored
by constructing dams. The water from the dam
flows down through pipes and rotates theturbines
of generators to produce electricity.

10. Advantages of hyropower:
i) Flowing water is a renewable source of energy.
ii) The electricity produced does not cause
pollution.
iii) The water stored in dams can also be used to
control floods and for irrigation.
Disadvantages of hydropower:
i) The initial cost is high.
ii) Large areas of land gets submerged and the
decomposition of vegetation produces methane gas
which is a green house gas.
iii) It causes displacement of people from large
areas of land.

13. d) Biomass energy :
 The waste materials and dead parts of living
things are called biomass. Eg :- wood, animal
dung, vegetable waste, agricultural waste,
sewage etc. Biomass is decomposed by
anaerobic microorganisms to produce biogas.
Biogas is a mixture of gases containing
methane, carbon dioxide, hydrogen and
hydrogen sulphide.

14. Biogas plant :
The biogas plant has a large underground tank
made of bricks and cement. The lower part is the
digester and the upper part has a dome with a gas
outlet. On one side of the tank above the ground is
a mixing tank and on the other side is an overflow
tank.
Animal dung is mixed with water in the mixing
tank and the slurry is sent into the digester. In the
digester the slurry is decomposed by anaerobic
microorganisms and after a few days biogas is
produced.
The gas is taken out through the gas outlet and
used for heating and lighting purposes. The slurry
left behind is rich in nitrogen and phosphorus and
is used as manure for crops.

16. e) Wind energy :
Wind energy is used in wind mills which converts
the kinetic energy of the wind into mechanical or
electrical energy.
The kinetic energy of wind can be used to do:
 mechanical work like lifting water from wells or
grinding grains in flour mills.
 It can also be used to rotate the turbines of
generators to produce electricity.
 A single wind mill produces only a small amount
of electricity.
 So a large number of wind mills in a large area
are coupled together to produce more electricity
in wind energy farms.

17. Advantages :
i) It is a renewable source of energy.
ii) It does not cause pollution.
iii) The recurring cost is less.
Disadvantages :
i) Wind is not available at all times.
ii) It requires a large area of land.
iii) A minimum wind speed of 15 km/h is
required.

19. a) Solar energy :
Solar energy is the energy obtained from the sun in
the form of heat and light. The heat energy is used
in solar heating devices like solar cooker, solar
water heater, solar furnaces etc.
The light energy is used in solar cells.
i) Solar cooker :
The box type solar cooker has an insulated box
painted black inside.
It is covered by a glass plate which allows heat to
enter inside but does not allow heat to escape out.
It has a mirror to reflect more sunlight into the box.
The food to be cooked is kept in containers inside
the box It can produce a temperature of 100° to
140°.

20. ii) Solar water heater :
A solar water heater has an insulated box
painted black inside with a system of copper
tubes. It is covered with a glass plate which
allows heat to enter inside but does not allow
heat to escape out. When water flows through
the copper tube it absorbs heat and becomes
hot.

21. iii) Solar cells :-
Solar cell is a device which converts solar energy into electrical
energy.
Solar cells are made from semi conductors like silicon,
germanium, gallium etc.
A single solar cell produces a voltage of about
 0.5 to 1 V and produces about 0.7 W electricity.
 So several solar cells are arranged in a solar panel to produce
more electricity.
Advantages :
i) It uses renewable source of energy.
ii) It produces electricity which does not cause pollution.
iii) It can be used in remote areas where there is no power
supply.

22. Disadvantages of solar cells:
i) It uses a special grade of silicon which is
expensive.
ii) Since silver is used for connecting the cells
together it is more expensive.
iii) The current produced is DC and to convert it
to AC increases the cost.

26. b) Energy from the sea :
Energy from the sea is obtained in three different forms. They
are
Tidal energy, Sea wave energy and Ocean thermal energy.
i) Tidal energy :
The periodic rise and fall of sea level due to gravitational
attraction of the moon causes tides.
A dam is constructed at a narrow opening
between the land and sea.
The movement of water during high tide and low tide can be
used to rotate the turbines of generators to produce
electricity.
ii) Sea wave energy :-
 When strong wind blows over the sea it produces huge
waves.
 The kinetic energy of the moving waves can be used to
rotate the turbines of generators to produce electricity.

27. iii) Ocean thermal energy :
There is a temperature difference between the
warm surface water and the cold water at the
bottom of the oceans.
This difference is about 20°C. The warm surface
water is used to boil liquid ammonia and the
vapour is used to rotate the turbines of
generators to produce electricity.
The cold water from the bottom is then
pumped up to cool the vapour back to liquid.

31.  The deeper regions of the earth’s crust is very
hot.
 This heat melts rocks and forms magma.
 The magma moves up and collects below at
some places called Hot spots. The
underground water in contact with hot spot
gets heated into steam at high pressure.
 By drilling holes into hot spots the steam
coming out can be used to rotate turbines of
generators to produce electricity.

34. d) Nuclear energy :
Nuclear energy is the energy is the energy released during nuclear
reactions.
During nuclear reactions some mass is converted into energy and so a
very
large amount of energy is produced during nuclear reactions.
Nuclear reactions are of two types. They are Nuclear fission and nuclear
fusion.
i) Nuclear fission : is a nuclear reaction in which the nucleus of a heavy
atom like uranium, plutonium, etc. splits into smaller nuclei with the
release of a large amount of energy. It is used to make atom bombs and
to produce electricity.
In a nuclear power plant the heat energy produced by a controlled
nuclear fission chain reaction is used to produce steam which rotates
the turbines of generators to produce electricity.

35. ii) Nuclear fusion :- is a nuclear reaction in which small nuclei
fuse together to form a heavier nucleus with the release of a
very large amount of energy. The energy of sun is produced
by the fusion of hydrogen nuclei to form helium nucleus.
It is also used to make the hydrogen bomb.
Advantages of nuclear energy :
i) It produces a very large amount of energy per unit mass
than any other
source of energy.
ii) If safety measures are taken, it is more environment
friendly than fossil fuels.
Disadvantages of nuclear energy :
i) The cost of a nuclear reactor is very high.
ii) The availability of nuclear fuel is limited.
iii) Nuclear reactors produce harmful nuclear wastes which is
difficult to dispose.

36.  The mobile farm power comes: from human,
draught animals, power tillers, tractors and
self propelled machines
 The stationary power is obtained from oil
engines (diesel, petrol, kerosene) and electric
machines.

37. Human Power
 The average power availability, in sustained
working,
 from a male agricultural worker is considered
as 60 watts (0.06 kW)
 while for a female worker it is considered as
48 watts (0.048 kW) and
 For child worker as 30 watts (0.03 kW)

38. Draught animal power: The power available from
draught animals is related to its body weight
For ex:
 Bullocks : 10-12% of body weight in summer and
12-14% in winter
 Buffaloes : 12% of body weight in all seasons
 Camels : 18% of body weight up to 7 h, 26% up to
6 h following 2 h work + 2 h rest schedule.
 Donkeys : 32% of body weight up to 6 h and 36%
up to 4 h in two shifts.

39.  Mobile Power from Tractors, Power Tillers and
Self-Propelled Reapers and Combines
 Big range of power are available on the
market depending on your land and
production

40.  Stationary Power from Diesel Engines and
 Electric Motors
 Depending on the size of thefarm and the
purpose of use

41.  Energy Conservation is the deliberate practice
or an attempt to save: electricity, fuel oil,
mechanical power, gas or any other
combustible material
 Energy Conservation is to be able to put to
additional use for additional productivity
without spending any additional resources or
money.

42.  Energy conservation is achieved when: growth
of energy consumption is reduced,
measured in physical terms
 Energy conservation can be the result of
several processes or developments( increase
of productivity or technology)
 Energy conservation and Energy Efficiency are
separate, but related concepts.

43.  Energy efficiency is achieved when energy
intensity in a specific product, process or
area of production or consumption is reduced
without effecting output, consumption or
comfort levels.
 Promotion of energy efficiency will contribute
to energy conservation and is therefore an
integral part of energy conservation
promotional policies.

44.  For example, replacing traditional light bulbs
with Compact Fluorescent Lamps (CFL) (which
use only 1/4th of the energy to same light
output). Light Emitting Diode (LED) lamps are
also used for the same purpose.

45. i) Minor ECOs
 These are simple, easy to implement, and
require less investment implementation time.
These may correspond to stopping of:
- leakage points, avoiding careless waste,
lapses in housekeeping
- and maintenance etc.

46. ii) Medium ECOs
 These are more complex, and required
additional investment and moderate
implementation time.
For example, replacement of existing
household appliances or any other energy
source by new energy efficient ones.

47. iii) Major ECOs
 These provide significant energy saving. They
are complex and demand major investment
and long implementation periods.
For example, replacement or major renovation
of old buildings, machineries etc.

49.  Psycho-social (people do not like to change:
social taboos and traditions)
 Economic (replacements often costly).

50.  Is the key of energy conservation and
management
 Energy audit is defined as "The Verification,
Monitoring and Analysis of use of energy
including: submission of Technical Report
containing recommendations for improving
energy efficiency with cost benefit analysis,
and an action plan to reduce energy
consumption".

51.  Energy Accounting
Energy accounting simply means record of
energy used in an establishment for comparison
against a budget or another standard of
performance.

52.  Systematic Approach To Decision Making
Energy Audit is the key to systematic approach
for decision making in the areas of energy
management. It attempts to balance the total
energy inputs with its use and serves to identify
all the energy streams in a facility. It quantities
the energy usage according to its discrete
functions.

53.  Effective Tool for Energy Management
Energy Audit is an effective tool in defining and
pursuing comprehensive energy management
programme. In this field also, the basic
functions of management like planning,
decision making, organizing and controlling,
apply equally as in any other management
subject.

54.  Ways of Usage of Energy
Energy Audit will help to understand more
about the ways energy and fuel are used in any
establishment, and help in identifying the areas
where waste can occur and where scope for
improvement exists.

55.  Construction and Stream Lining
The Energy Audit would give a positive
orientation to the energy cost reduction,
preventive maintenance and quality control
programme which are vital for production and
utility activities/.

56.  Ideas and Feasible Solution
In general, Energy Audit is the translation of
conservation ideas into realities, by blending technically
feasible solutions with economic and other
organizational considerations within a specified time
frame.
 In brief energy audit is an in-depth study of a facility
to determine how and where energy is being used or
converted from one form to another, to identify
opportunities to reduce energy usage, to evaluate the
economics and technical practicability of
implementing these reductions and to formulate
prioritized recommendations for implementing
measures to save energy.

62.  Comparison of energy utilization of different
crops
 Energy accounting of a specific crop from
tillage to harvesting.
 Energy Audit in a small scale village industry
 Energy accounting of a brick kiln
 Energy accounting of flour mill
 Energy Audit in ISAE Farm

63.  Students will be given different papers to
analyze and submit the findings
 Three types of papers are given

64. 1. Explain how conventional energy sources
are used in Rwandan Agriculture and give 5
examples
2. Describe Non conventional energy sources
use in Rwandan Agriculture and give 5
examples
3. What are the most used energy sources in
Rwandan Agriculture? Why is it so?
4. In your own words define “Energy
management for Agriculture”

65. Read the Paper and understand it before answering
these following questions
Paper Title: Energy Efficiency of Conventional,
Organic, and Alternative Cropping Systems for
Food and Fuel at a Site in the U.S. Midwest( by S I
E G L I N D E S . SN A P P , A N D G . P H I L I P R O
B E R T S O N )
1. What are the objectives of this study?
2. Describe the need of this study
3. Discuss briefly on materials and methods used
4. Compare energy efficiencies in 5 systems which
are discussed in this paper

66. Read the Paper and understand it before answering
these following questions
Paper Title: Impacts of organic farming on
efficiency of energy use in Agriculture (by David
Pimentel)
1. Write down the main objectives of this paper
2. What are the main differences in energy
requirement between conventional and organic
farming?
3. What are the benefits of organic farming over
conventional farming?
4. Why organic farming is preferred?

67. Read the Paper and understand it before answering
these following questions
Paper Title: Energy use pattern analyses of
greenhouse vegetable production (By M. Canakci, I.
Akinci)
1. Describe the objectives of this study
2. What is the relationship between energy input
and crop yield on different crops discussed in
this paper.
3. Briefly discuss materials and methods used in
this paper.
4. Which plant does not require much energy for
production?

68. THANK YOU !!!