Biochemical engineering, Mekelle university,Teklemariam Negash

1. Mekelle university
EIT-M
Department of Chemical Engineering
(Biochemical Engineering Stream)
Sustainable Energy Technology (Cheng5201)
Title: Hydropower Energy Potential in
Africa and Ethiopia Share
Prepared by: Group member -1-
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2. Outline
1
• Introduction
• Hydropower potential in Africa
2
• Hydropower potential in Ethiopia
• GERD
3
• Advantages and disadvantages
2

3. INTRODUCTION
Hydropower-what is it?:
One of the most widely used renewable source of energy for
generating electricity.
Is ultimately derived from the sun, which drives the water
cycle.
Comes from water at work, water in motion.
Emissions-free, with virtually no CO2, NOx, SOx, hydrocarbons,
or particulate.
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4. Cont…
Hydrologic cycle
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5. Cont…
How It works?  In nature, energy cannot be
created or destroyed, but its
form can change.
 The dam creates ahead or
height from which water
flows.
 The fast-moving water
pushes the turbine blades
and turns the generator.
 Generator converts ME to EE.
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6. Cont…
Essential Elements of Hydropower Plant:
Catchment Area
Dam
Spillway
Gate
Penstock
Power House (Turbine and Generator)
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7. Cont…
Power house: building in which the turbines and generator are
housed.
Turbine: converts the potential energy of water in to shaft work,
Turbines are classified as impulse and reaction turbines.
The classification depends on the nature of working on the baldes.
Impulse Turbine : all the available head of the water is converted in
to kinetic energy in the nozzle.
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8. Cont…
The water shoots out of the nozzle in a free jet in to a bucket.
They are Suitable for high head and low flow applications.
Reaction turbine: the entire flow takes place in a closed conduit
system.
The runner converts both the KE and PE in to mechanical energy.
They are Suitable for lower H and higher Q applications.
 Example: GERD is planned to use reaction turbine.
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9. Cont…
Pelton Turbine Francis Turbine
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10. Cont…
How Power is computed?
The actual output of energy at a dam is determined by:
volume of water released (discharge) and
the vertical distance of water falls (head).
Theoretical Power: is the anticipated power which is given by an
engineer.
PT = ρ*Q*g*H
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11. Cont…
Actual Power: is power at
hand (real).
Where:
 m = mass of water in kg
 g = gravitational const. = 9.81
m/s2
 ρ= water density = 1000 kg/m3
 H = head (m)
 Q = water flow rate in m3/s
 ηt = turbine efficiency
 Ƞg = generator efficiency
PActual = ρ*Q*g*H* ηt*ηg
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12. Cont…
Selection of Site for a Hydropower Plant:
The following factors should be considered while selecting the site
for hydropower plant.
o Availability of water
o Water storage capacity
o Available water head
o Accessibility of the site
o Distance from the load center
o Type of land of site
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13. Hydropower potential in Africa
Africa Overview:
o Africa has abundant hydropower resources.
o Around 92% of technically feasible potential has not yet been
developed .
o Central Africa has about 40% of the continent’s hydro resources.
o East Africa having about 28% potential.
o At the end of 2014 there was 28 GW of hydro capacity installed in
Africa.
o The Congo River has the largest discharge of African rivers,
followed by the Zambezi, the Niger and the Nile.
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14. Cont…
Hydropower Target (SOURCE, IRENA,2017)
Country Target Year
Angola 9,000 MW 2025
Ethiopia 22,000 MW 2030
Kenya Increase by 5% of
current
2031
Morocco 2,000 MW increase 2020
Mozambique 5,400 MW 2025
Nigeria 2,000 MW increase 2025
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15. Cont…
Top six countries having installed hydropower (SOURCE, IRENA,2017):
Rank Country Power (MW)
1 Ethiopia 4050
2 South Africa 3583
3 Egypt 2800
4 DR Congo 2509
5 Zambia 2392
6 Sudan 2250
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16. Cont…
Total
potential
(280GW)
Currently
tapped
(28GW)
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o Huge gap between potential and actual hydropower production.
o 10% of the total potential is currently tapped.
Source IEA, 2014

17. Hydropower potential in Ethiopia
Ethiopia’s economy is fastest-growing averaging an 11 per cent
increase in GDP each year.
The GDP population growth rate of 2.3 %, has led to a
staggering 14 % increase in energy demand.
Currently only 25 % have power connectivity.
Ethiopia is one of the richest water resources in Africa.
Has an exploitable hydropower potential of 45,000 MW.
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18. Cont..
HYDROPOWER
75%(45000MW)
WIND POWER
17%(10000MW)
GEOTHERMAL
8%(5000MW)
Source, EEPCO
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19. Cont…
GERD:
o is being built in the Benishangul-Gumuz region of Ethiopia.
o The highest dam in Africa.
Some facts about GERD:
o Dam height: 145m.
o Water capacity: 74 billion cubic meter (13 times total annual water
consumption).
o Power capacity: 6450MW (It will almost triple electricity
production).
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20. Cont…
GERD and its Potential Impacts:
The positive and negative potential impacts of GERD are seen as;
Energy
 Biodiversity
Water flow
Agriculture
Social impact
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21. Advantages and Disadvantages
Advantages
o Low Maintenance and
operation charges.
o Have a longer life.
o Emissions-free.
o useful for flood control,
irrigation purposes and
recreation.
o The energy is virtually free.
o Much more reliable than
wind, solar or wave power.
Disadvantages
Economic issues:
o Are capital-intensive.
o High cost of transmission
lines.
Social and Political Issues:
o Displacement of people.
o political dispute between
countries.
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