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SULPHUR AND ITS COMPOUND SULPHUR AND ITS COMPOUND:A.SULPHUR (S) Sulphur is an element in Group VI(Group 16)of the Periodic table . It has atomic number 16...





ENERGY is the power required to carry out an activity e.g. diesel, electricity, etc.

Sources of Energy

Classified into 2 types: renewable and non-renewable sources of energy.

Renewable Sources of Energy

Which can be regenerated and used over and over again.

Types of Renewable sources of Energy

  1. Sun
  2. Wind
  3. Water (geothermal, hydro power, tides and waves).
  4. Biomass (wood, biogas)


Energy from the sun is called solar energy.

The sun is the primary source of all types of energy.

Solar radiation can be converted into 2 types of energy.


Solar panels are used to tap solar energy which is then used to heat water in coiled pipes which are inside which are painted black.

Mirrors are used to converge rays of the sun on one spot which are then used to heat water or cook food in a pot.

Suns rays are reflected and focused on crops to dry them.


Photo- voltaic cells are used which when sunlight shines on them they generate electricity which is then stored in batteries.

Advantages of Solar Energy

  • Cheap because it’s obtained from sunlight which isn’t paid for.
  • Requires minimal maintenance once tapping equipment has been installed.
  • It doesn’t pollute the environment like fossil fuels (environmentally friendly)
  • Can be stored in batteries and used when there is no sunlight.
  • It’s inexhaustible i.e. available as long as the sun continues to shine.
  • Available in all parts of the world.


  • Can’t be used to run heavy machinery.
  • Tapping equipment e.g. solar panels are expensive to buy.
  • The batteries which it’s stored in are cumbersome to carry around.
  • It fluctuates in various seasons throughout the year.
  • Large numbers of solar panels are required to produce useful amounts of energy.


Wind energy is mainly used in arid and semi-arid areas where wind flow isn’t obstructed by vegetation.

  • Wind is harvested using wind mills and converted into mechanical energy which is used for pumping water, grinding grain and generating electricity.
  • Wind energy is also used to propel ocean going vessels e.g. dhows.


  • It is an inexhaustible source of energy.
  • It doesn’t pollute the environment.
  • Land between the windmills can be used for other purposes.
  • Can be produced on small scale basis for local consumers.

Disadvantages/ Problems.

  • Wind mills for harvesting it are expensive to buy and install.
  • The equipment for harvesting is relatively expensive to maintain.
  • Many windmills are required to provide a significant amount of electrical energy.
  • It fluctuates when the strength and direction of wind changes.
  • The large tracts of land it requires (wind farms) alter the environment beauty.
  • It’s not available in many areas except in open areas.


Geothermal Power

Steam from underground is heated when in contact with hot rocks.

The steam finds its way to the surface through fissures or cracks.

The steam is tapped and used to turn turbines and thus generate electricity e.g. at Olkaria in Kenya.


  • Cheaper as no fuel is required to turn turbines.
  •  It is Continuous.
  • It’s inexhaustible unlike hydro-power which depends on water levels.
  • The cost of operating geothermal power station is low compared to    hydro-power station.
  • A good supplement for other sources of energy.


  • Causes noise pollution from generation plant.
  • Not available in many areas where there aren’t hot springs and geysers.
  • Gases released with steam may pollute the environment e.g. sulphur dioxide, hydrogen sulphide, methane, ammonia, etc.
  • Its exploration is expensive because it requires expensive technology.


  • Power obtained from falling water.
  • Most widely used renewable source of energy.
  • Used to generate electricity (HEP) when falling water is directed to turn turbines connected to generators to produce electricity.


  • It doesn’t pollute the environment.
  • It’s inexhaustible.
  • Hydroelectric power can be transmitted over long distances using cables.
  • Dams for HEP generation create lakes which can be used for recreation, irrigation and fishing.
  • HEP can be used for many purposes e.g. transport, cooking, etc.
  • It’s reliable because significant levels of energy are produced.


  • Affected by fluctuation of water levels in reservoirs.
  • Construction of HEP generation dams displaces many people.
  • It causes inconvenience to migratory species of fish.
  • The cost of constructing and running hydro-power plants is high.
  • Dams may break and destroy a lot of property and lives downstream.
  • Not available throughout the world.

Tides and Waves

  • Dams are built across an estuary.
  • Incoming and outgoing tides rotate turbines and electricity is generated in similar way as hydro-power.


All forms of energy released by plants and animal wastes.

Wood fuel

Firewood, charcoal and saw dust which are used for cooking and heating.

It can be exhausted if its cut at a higher rate than they are being replaced. so it requires management if it has to be sustained.

Advantages of Wood

  • It’s a cheap source of energy.
  • Available almost throughout the world.
  • No maintenance cost is needed.
  • Ashes from burned firewood can be used for plastering houses and as a fertilizer.


  • Dirty because when burning it gives off smoke and soot.
  • Pollutes environment through the gases it emits.
  • Requires a big storage area.
  • Its overexploitation leads to deforestation leading to problems of soil erosion, global warming and shortage of water.

Power Alcohol

Agricultural wastes e.g. straw, molasses and cassava are fermented to produce power alcohol which is directly used to heat or blended with gasoline to run machines.


Human and animal wastes are used to produce methane (biogas) through fermentation which is used for cooking and lighting.

Advantages of Biomass

  • An inexhaustible source of energy.
  • Fuels are efficient and relatively clean.
  • Cheap because it makes use of waste products.
  • Production of biogas is cheap as it doesn’t require advanced technology.
  • Biogas gives twice as much heat as natural gas.
  • Slurry left behind when biogas is being made can be used as fertilizer.
  • Available throughout the world.


  • Biogas digesters require a lot of space and can’t be set in congested areas.
  • Can’t be transported to distant places.
  • Contributes to pollution which causes global warming.


Examples of Animals and Their Uses

  • Oxen for ploughing and pulling carts.
  • Horses for transporting by riding on their backs.
  • Donkey for transporting of goods on their backs or by pulling carts.
  • Camel for transporting goods and people on their backs.
  • Elephant in Burma and India for transporting logs from forests


  • Inexhaustible because animals keep multiplying as a result of production.
  • Available in all parts of the world.
  • Cheep to maintain as they only require food and water.
  • Animals are flexible because they are able go through forests and narrow paths unlike motor vehicles.
  • Some are slaughtered for meat when they outlive their usefulness e.g. oxen, camels etc.


  • They are prone to diseases and fatigue.
  • They can die as a result of too much work.
  • Their use is restricted only to rural areas.
  • They can only transport small loads.
  • They can only do limited work because they tire easily.

Non-renewable Sources of Energy

  • Sources of energy which are exhaustible if they aren’t well managed.
  • They include petroleum, coal and uranium.


A black or brown rock made of carbon.

  • Mud, sand and other materials are deposited over vegetative matter such as tree trunks and branches.
  • Deposited material prevents decomposition and also exerts pressure on it causing great heat.
  • Peat layers are formed which gradually change into coal.

Usage of coal has declined due to:

  1. Discovery of other forms of energy such as petroleum.
  2. Exhaustion of old accessible mines.
  3. High cost of mining coal.

Advantages of Coal

  • More efficient in thermal generation of electricity than oil.
  • Most suitable in the smelting of iron.


  • It leaves a lot of dirt on any surface it touches.
  • It leads to formation of smog and smoke which is a health hazard.
  • Its mining leads to environmental degradation.


Consists of gaseous and liquid hydrocarbons from animal and vegetation matter laid on sedimentary rocks.

Natural gas and petroleum are extracted from the same oil wells.

Petroleum is refined to get by-products such as motor oil, diesel, kerosene, gasoline, jet fuel, lubricants, liquid and petroleum gas.

Natural gas occurs alone or is found on the upper layers of crude oil.

It’s a mixture of hydrocarbons with methane making about 90% and other gases such as propane, ethane and butane.

It’s used for domestic purposes, generation of thermal electricity and for industrial activities.


  • A clean source of energy to use.
  • Cheap to transport by pipes to distant areas.
  • Transport and maintenance costs are low.
  • Easy to use as one needs only switches and burners.
  • Free of the effects of weather changes.


  • An exhaustible source of energy.
  • Accidental fires can occur incase the gas leaks or the pipe is damaged.
  • It can greatly pollute the environment incase of accidental fires occurrence.
  • Expensive for low income groups.


A naturally occurring radioactive material used to produce nuclear energy in fusion and fission in reactors.

A lot of heat is produced and the water used to cool the heat producing core is heated and turns into steam used to generate electricity.


  • It’s a long lasting supply of raw material.
  • It produces large amounts of energy.
  • It doesn’t produce green house gases.


  • It’s expensive to construct a nuclear reactor.
  • Wastes from a nuclear power station are difficult to dispose because they are radioactive for 100 years.
  • It is an exhaustible source of energy.

HEP Projects in Kenya

Factors Favouring Development of HEP

Physical Factors

  1. A large and constant volume of water such as R. Tana and its tributaries.
  2. Can be located on areas with falling water such as on rapids, water falls, and Knick points.
  3. Deep and narrow valley. Deep to ensure a large capacity for the reservoir and narrow to minimize the cost of constructing the dam.
  4. Hard basement rocks to reduce the amount of infiltration and also to provide a strong foundation for the dam.

Human Factors

Area for dam and reservoir construction should be sparsely populated to minimize the cost of relocating people.

There should be presence of industries and urban areas to provide market for electricity to make the project economically viable or bring a profit.

Construction of an HEP station requires adequate capital because it’s expensive to construct a dam, to maintain it, to transmit power and to compensate the displaced people. Kenya is financed from external source e.g. Sondu Miriu which is financed by Japanese government.

When referring to Kenya you should say: ‘There is presence of …’

Development of HEP in Kenya

By the dawn of independence there was few industries and hence low demand for electricity.

Few HEP stations available were set up to supply power for agricultural processing.

The earliest stations were Mesco on R. Maragua, Ndula on R. Thika and Sagana on R. Sagana.

The rest of power supply came from diesel plants in Kipevu.

There was power which was being imported from Uganda which was connected in 1955.

Demand for electricity increased as more industries were established.

The country opted to use her water resources to provide electricity and reduce her reliance on power from Uganda.

  1. Tana was identified as the one with the largest potential.

Seven sites appearing as a cascade were identified along the river where the Seven Forks Scheme was launched.

  • Kindaruma was the first project to be established which was completed in 1968.
  • Kamburu followed which was completed in 1974.
  • Gitaru was next which got completed in 1978.
  • Masinga which is a multipurpose project was completed in 1981. It has the largest lake. It’s a reservoir for the rest of the dams downstream and the water is also used to provide water for irrigation.
  • Kiambere was the last station downstream completed in 1988.
  • The other proposed power stations to complete the Seven Forks project are Mutonga and Grand Falls.
  • The other HEP stations are Turkwel Gorge on R. Turkwel which was completed in 1991 and Sondu- Miriu which was expected to be completed in 2008.

It’s the main source of electricity accounting for 72% of power production.

The stations are maintained by Ken Gen which sells power to KPLC which distributes it to consumers at a fee.

Benefits of Tana River Projects

  1. The reservoirs provide power for irrigation and domestic use.
  2. The dams promote transport by serving as bridges across the rivers.
  3. The dams are a tourist attraction e.g. Masinga tourist lodge provides recreational facilities.
  4. The dams provide fresh water fisheries.
  5. The projects have generated employment to people thus raising their standard of living.

Problems Facing the Tana River Projects

  1. Shortage of capital to purchase spare parts which has interfered with maintenance of machinery in the power house.
  2. Fluctuation of the water levels of R. Tana due to drought in the catchment areas and evaporation due to flowing through the dry Nyika region which affects power generation.
  3. Siltation of dams which occasionally blocks the tail race tunnels leading to a low volume of water and dredging is required which is expensive.
  4. Inadequate skills and technology which causes failure to maximise on power production.

HEP Projects in Uganda

It has the largest renewable fresh water resources in E. Africa.

It is endowed with numerous rivers and lakes with high potential of electricity generation.

The country receives an average of 1000mm of rain throughout the year.

  1. Nile which flows out of L. Victoria has the highest potential.

Where it flows out it has provided a natural water fall.

Owen Falls Dam was built on the site in 1954.

It’s the Africa’s largest storage dam.

It supplies most of Uganda’s electricity (162MW) and exports 30MW to Kenya.

The presence of power was a catalyst to industrial development e.g. Njinja town a few metres from the dam became a scene of several industries to use the cheap electricity nearby.

The country is developing another power station below the Owen Falls.

Kikagat River to the south provides power around Mutukula and Kabale areas in S.W Uganda.

Mobuku River supplies most of the power used in the copper mines at Kilembe.

HEP Projects in Africa

Africa has the largest concentration and potential areas of HEP generation.  The potential hasn’t been utilised due to:

  1. Inadequate financial resources. Where the projects are to be established the countries seek external borrowing of money which is paid for many years overburdening the concerned countries.
  2. Some of the potential areas being in remote areas far away from densely populated areas and industrial areas.
  3. Some of the countries are lowly industrialised which means there isn’t adequate market for HEP making the venture economically unviable.
  4. Some of the rivers with potential for HEP generation don’t have constant volume of water throughout the year due to seasonal fall of rain which affects power generation.

Some of the major projects are:

  • Aswan on R. Nile
  • Kariba (shared among Zambia and Zimbabwe) and Cabora Bassa on R. Zambezi.
  • Kainji on R. Niger
  • Akosombo in R. Volta (Ghana)
  • Owen Falls (Uganda) and Sennar on R. Nile
  • Vanderkloof on R. Orange
  • Inga and R. Le Marinel on R. Congo.

HEP Projects in Tanzania

  • Nyumba ya Mungu dam and Hale dam on R. Pangani.
  • Kagera
  • Malagasi

Geothermal Power Projects in Kenya

Geothermal electricity is generated in areas which experience Vulcanicity where:

  • Magma or hot rocks come into contact with percolating water.
  • The water is heated beyond its boiling point (superheated).
  • The steam escapes through cracks and holes to the surface
  • The steam is harnessed using pipes and used to turn turbines that drive electric generators.

In Kenya areas with the greatest potential for geothermal power are found within the Rift Valley from L. Magadi to L. Turkana on Kenya-Ethiopia border.

Geothermal power generation is carried out at Olkaria to the south of Naivasha.

It accounts for 10% of the country’s power needs.

Other potential areas are:

  • Bogoria which has the highest potential with numerous hot springs and geysers by it shores.
  • Eburu to the north of L. Naivasha
  • Menengai crater region
  • Areas around L. Baringo
  • Magadi
  • South of L.Turkana.
  • Between mountains Longonot and Suswa

Problems of Energy Development in Kenya

The aim is to reduce overdependence on imported oil.

  1. Inadequate capital which causes the country to seek external borrowing of money which is paid for many years overburdening the country.
  2. Small market for power because of the high cost of connection which prevents its horizontal spread.
  3. Seasonal fluctuation of water levels in dams due to low rainfall on catchment areas and some rivers flowing through dry areas where much of water is lost through evaporation which leads to inconvenience to consumers because of power rationing.
  4. Regular siltation of dams due to deposition of soil which requires regular dredging which is quite expensive.
  5. Location of some power generation plants in remote areas making it expensive to transport power for long distances.
  6. There is limited spread of solar power in rural areas because the equipment is expensive to install and lack of acceptance because it fluctuates with seasons.
  7. There is lack of acceptance of wind power and many people use diesel to pump water instead of it.
  8. There is problem of overexploitation of wood fuel as a result of population increasing at a faster rate which has led to deforestation leading to soil erosion and reduced amounts of rainfall as a result of the effect on water cycle.

Significance of Energy

  1. For domestic use e.g. wood and charcoal for cooking and heating, etc.
  2. For use in industries e.g. electricity, petroleum, etc.
  3. Used in transportation e.g. electric cars, diesel and petrol used in motor vehicles, etc.
  4. Used in agriculture e.g. diesel for tractors which draw ploughs, electricity for milking machines, etc.
  5. Used in water supply where diesel engines wind mills and solar power is used to pump water.
  6. Used for medical purposes where electricity is used to run equipment for diagnosis e.g. X-Ray and scanning machines and in refrigeration to preserve specimens on medicine research.

The Energy/Oil Crisis

Situation whereby the demand for oil is higher than the amount that is being supplied leading to high oil prices.


  1. Over-reliance on petroleum and its products.
  2. High oil prices due to sharp rise in oil demand.
  3. Economic and political sanctions
  4. Uncertainties in oil supplies to consumers.
  5. Rapid depletion of oil reserves.
  6. Conflict in the Middle East especially between Israel and Palestine.
  7. Exhaustion of wood fuel
  8. Mismanagement of energy
  9. Oil production limits set by OPEC
  10. Artificial shortages by countries like Russia and USA relying on oil from other countries and conserving their own.

Examples of Energy Crisis in the Past

  • 1973 and 1974 when there was war between Israel and Arab countries. The Arab countries which are OPEC members withheld oil supply to Israeli supporting countries e.g. USA and the result was sharp increase in oil prices.
  • 1991 first Persian Gulf war caused by triggered by Iraq invasion of Kuwait caused by:
  • Iraq’s claim that Kuwait was its territory.
  • Kuwait was taking oil from Iraq’s oil from Rumaila fields which lay beneath both countries.
  • Kuwait was exceeding the oil production limits set by OPEC.

Many Kuwait’s oil fields were set on fire and Iraq dumped about 465 m gallons of Kuwait’s crude oil to the Persian Gulf.

There resulted a major oil crisis which was worsened by the trade embargo.

  • 2003 second Persian Gulf War. Iraq had failed to destroy weapons of mass destruction which she had agreed to do for the 1991 war to end. The war led to a rapid increase in oil prices from US$35 at the start of war to US $50 by 2004. It forced OPEC members to increaser daily crude oil outputs by 8% to stabilise prices.

Impact of Energy Crisis

  • Increase in the prices of many commodities as a result of increase in the cost of production and transportation where oil is used to provide power and as a raw material in some industries.
  • Increase in the prices of imports due to high crude oil prices which affect the balance of trade by causing earnings from exports to be lower than the cost of imports.
  • High rates of inflation or devaluation of currency as a result of commodity prices rising high due to the cost of imports being passed to the consumers.
  • Industries are forced to lay off workers because of the high cost of production which can cause losses.
  • It causes the price of other forms of energy e.g. charcoal and gas also to become expensive.
  • Developing countries running into heavy dept as a result of borrowing heavily to pay for oil loans which are paid at high interest rates making the country unable to invest in development projects.
  • Decrease in agricultural production as a result of decrease in the use of agricultural inputs such as fertilizers due to their high cost brought about by increase in oil prices.
  • Decline in the number of tourists as a result of escalation of oil fares making it very expensive to travel.
  • Environmental degradation as a result of environmental degradation brought about by the high demand for charcoal and firewood which leads to soil erosion and low rainfall amounts. 


  • Developing alternative sources of energy e.g. solar, biomass, Geothermal and HEP.
  • Management and conservation of energy.
  • Developing nuclear energy to enhance self sufficiency in energy provision.
  • Encouraging industries to use coal which is slightly cheaper than petroleum.

Management and Conservation of Energy

Management of energy is effective planning and control of energy resources.

Management Measures

  • Control of importation of vehicles with large engine capacity which consumes a lot of fuel.
  • Encouraging many people to use public transport in order to reduce the number of vehicles on roads and thus fuel consumption.
  • Educating people through mass media to create awareness on the importance of conserving energy.
  • Improvement and proper planning of road network to reduce traffic jams in which a lot of fuel is wasted.
  • Agroforestry, afforestation and reafforestation programmes to reduce overexploitation of natural forests.
  • Banning logging, selective felling of trees and resettling people who have settled into forests.

Conservation of Energy

Conservation of energy is using available energy resources in the most effective manner to ensure there isn’t wastage.

Conservation Measures

  • Putting off electricity gadgets when they are not in use.
  • Proper motor vehicle maintenance in order for them to use fuel efficiently.
  • Encouraging use of public transport which carries many people at a go e.g. buses.
  • Encouraging use of renewable sources of energy e.g. solar, wind and biogas to save on oil and wood.
  • Encouraging use of energy saving stoves which use little charcoal and produce a lot of energy.