Alternative Energy Sources around The World

 In this website we aim to provide information about alternative energy sources around the world, and specifically  to students of a high school level.

 Everyone knows the effect that greenhouse gas production and global warming is having on our earth. We feel that it is vitally important for individuals, and especially governments, to start taking these problems seriously; before it is too late. Even though technology has greatly advanced in the last decade most countries around the world still use fossil fuel-based methods of energy production. The use of these fuels has two major problems; it depletes the natural supply and eventually we will run out; and the burning of the fuel (i.e. coal) creates vast pollution in the form of greenhouse gases (GHG's such as carbon monoxide and dioxide, and sulphur dioxide). It is these gases which lead to global warming and slowly destroy our planet. Only through the use of alternative sources of energy (which are virtually non-polluting) can we slow down this destruction and save our planet.

1.Solar Power

WHAT IS SOLAR POWER?
 Solar power is a viable alternative to fossil fuels and some alternative energy sources, as it gives off no carbon dioxide waste and uses the natural energy from our sun to generate electricity. After the lifetime of the panel, the materials that were used to make it could be recycled as no material is used in the energy generating process. There is also a lot of room for solar power to be used in the development of 3rd world economies, as it is extremely cost effective in the long run.

HOW DOES IT WORK?
 Solar panels have always been thought to be very expensive as it used to be made only from the purest silicon. Solar power has in many ways been eliminated as a viable option as a result of its high manufacturing costs. But a recent breakthrough in the hunt to find an alternative to silicon has dramatically decreased the price of solar power, and also increased it’s effectiveness. This achievement came from South Africa’s own Professor Vivian Alberts from the Johannesburg University and his team of physicists, who have formulated a new procedure of making solar panels using copper-indium-gallium-diselenide (CIGS).

 The production of CIGS solar panels is very complex and any slight deviation from the purest, high-quality elements can result in an ineffective solar cell.
1. Three metals: copper (Cu), gallium (Ga), and indium (In), have to be formed in an extremely pure alloy.
2. Next, the alloy that was formed needs to be converted into an equally pure semiconductor. This is done by adding selenium (Se)into the alloy. This creates a completely new crystal structure forming the CIGS layer of the cell.
3. Then a buffer layer of other semi-conductors are laid carefully on the CIGS layer.
4. The cell is then finished off by attaching conductive electrical contacts (usually molybdenum) on either side

IS IT RENEWABLE?
 Solar power is one of the most renewable ways of energy production. The sun as the energy source is, at least in the foreseeable future, endless and will keep providing us with power. There is no way for us to use up the sun and we don't even have to replenish it. Therefore solar power is definitely a renewable means of energy production.

APPLICATIONS OF SOLAR POWER
 The use of CIGS in the productions of solar panels as an alternative to silicon, gas been undergoing research since 1974, but scientists struggled to find reliable, repeatable, commercially affordable processes to produce this type of solar panel. Professor Alberts revolutionised this industry in inventing an entirely new procedure based on the way that the atoms behave from the beginning to the end of the process. His procedure is going to be implemented in the first full-scale CGIS production plant that uses this procedure, currently being built in Germany by IFE Solar Systems a company that has invested R500-million in this South African invention.

ADVANTAGES
· The sun's energy is free to use, which makes the process cheaper.
· The process is completely non-polluting.
· Can be used in a wide variety of locations the world over. Wherever there is sun.

DISADVANTAGES
· Cost of the panels and equipment is expensive. This will, however, become cheaper in time.
· Can only work when the sun is available; therefore weather dependant.

2.Wind Power
WHAT IS WIND POWER?

 Wind power is when we covert the power of the wind, physical energy, to more useful types of energy. The most common type of energy it is converted to is electricity.

A wind farm is a large area of land on which there are a number of wind turbines generating electricity, as a power plant does. When creating a wind farm one must make sure that the spacing between the turbine is sufficient as not to cause energy/wind loss.

HOW DOES IT WORK?

 The most common type of energy generated from wind is electrical energy. This is by making the use of an electrical generator which is turned by turbine blades which are turned by the wind and thereby turning the turbine, creating electricity.

IS IT RENEWABLE?

 Yes, as we find wind throughout the world and the minimum wind speed needed is from 16km/h upwards. The wind needs to have a constant speed, should be non-turbulent and must not be subject to strong bursts of air. The wind also blows faster the higher into the atmosphere you go. That is why most wind farms are found quite high up.

APPLICATIONS OF WIND ENERGY

You get three types of wind farms:

• On Shore
• Near Shore
• Off Shore

On Shore

 If a wind farm is about three kilometres away from the nearest shoreline it is regarded as an on shore wind farm. They are normally installed in the mountainous areas as the higher you go the faster the wind blows. The cliffs and mountains also contribute to speeding up the wind. Before setting up a wind farm much research has to be done because the smallest diffenrence of placement could even double the turbines' output.

Near Shore

 If a wind farm lies on land within three kilometres to the nearest shore line or lying on the water within ten kilometres from the shore it is considered a near shore wind farm. Sea shores tend to be very windy as the land and sea heat up and cool down at different rates, creating strong winds. The wind from the sea is also more dense and therefore carries more energy than the same speed wind in mountainous terrain.

Off Shore

 If a wind farm is more than ten kilometres into the sea form a shore then it is considered to be off-shore. Off-shore turbines are found in deep sea waters and are usually much larger than their land-based siblings. The wind over the open sea is considerably faster and stronger than that of land because they have no obstacles in their way such as trees and buildings to affect the wind speed. Their distance from land allows companies to create larger ones and they do not need to worry about any noise factors as they are a considerable distance from the shore. The off-shore wind farms are the most expensive to build as they need to be set in the open ocean where they are subjected to all the earths's elements, therefore raising the maintence cost of off shore wind farms. The cost involved in transferring the electricity from the turbine to the land could be large as there is a large distance to be covered. Off shore wind farms are much larger than the on shore counterparts as there is much more space in the open sea as opposed to land and there are no worries of people complaining about them in the sea.

Airborne

 This is a new concept with no product available as yet but there are companies busy developing an airborne wind turbine which is suspended high in the atmosphere thereby obtaining the fastest and strongest winds available.

ADVANTAGES

• Wind is free and in abundance and we have the technology to capture the power of wind efficiently
• The costs for wind turbines are only initial costs; once the turbine is built there are minimal maitenence costs which are involved.
• In the rural areas which are not connected to a country's power grid it can be used to generate its own power.
• The space which a wind turbine takes up on land is very small as the moving parts are quite a distance above the ground.
• Wind turbines produce energy with minimal damage to the worlds environment and produces "clean power".

DISADVANTAGES

• Some pollutants are given off into the atmosphere in the creation of a wind turbine.
• Wind turbines can be quite noisy.
• The wind speed is not constant and therefore there will not always be a definite supply of electricity form a wind turbine.
• Large numbers of wind turbines are needed to power towns, as the largest turbine is able to produce electricity to sustain only +/- 500 homes.
• Many people feel that wind turbines are unsightly and that they should not disrupt the natural beauty of landscapes.

3.Nuclear Power

WHAT IS NUCLEAR POWER?

 Nuclear power is an alternative power source that uses the nuclear fission of uranium to create heat and, thereby, through a heat transfer mechanism and turbines, create electricity.

HOW DOES IT WORK?

 For a nuclear reactor to create energy it is necessary for nuclear fission to take place. This occurs when an atom is split into smaller particles and an enormous amount of energy is released in the process. Uranium is used as the fuel for the reaction as it is radioactive, and is therefore unstable enough to be broken down into smaller parts. The uranium atom absorbs a neutron and splits into two equal parts and energy is created. This kinetic energy becomes heat energy as the particles slow down, and it is this heat energy, which is used to produce electricity. The heat is moved through a transfer medium, such as water, and is used to turn water into steam. This steam turns a turbine, which is connected to a generator. As the turbine turns the generator it creates electricity, which is then transferred to the consumers.

IS IT RENEWABLE?

 Nuclear power is renewable as it doesn't use fossil fuels or other non-renewable resources in the production of energy; however it isn't as renewable as some of the alternatives, such as wind or solar power, which rely solely on natural phenomena to create their power. In the short term it is unlikely that uranium will run out, but eventually it will. Therefore we can say that nuclear power is only renewable in the short term.

APPLICATIONS OF NUCLEAR POWER

 About 440 nuclear reactors are used around the world to produce about 17% of the world's electricity but in theory nuclear fission can be used for much more. At the end of the Second World War the Allies secured victory by dropping the atomic bomb on Japan. The bomb uses the same principles of splitting the atom as the nuclear reactors do in creating electricity. On a smaller, less destructive scale, the theories of nuclear fission are used daily in medicine. Scanning devices and the treatment of cancer both use the radiation from splitting an atom.

ADVANTAGES

• As an alternative to normal coal-based electricity production nuclear power is favourable as it is much more efficient than coal (250g of uranium produces 20000 times more electricity than 250g of coal) and is far less polluting, especially to our atmosphere, as no harmful greenhouse gases are emitted. (ie. carbon monoxide, sulphur dioxide, nitrogen oxide etc.).
• It is generally a reliable process that can be counted on to produce electricity for many years (average availability over three years is about 80%).
• The amount of waste produced each year would cover only your dining room table!
• The waste is stored in fire-, water-, and earthquake-proof capsules to ensure safety.

DISADVANTAGES

• There is pollution in the form of radioactive waste but with new technologies the process is becoming cleaner and safer each year.
• The possibility of radiation leakage or plant meltdown. This is possible in theory and has happened in the past (Chernobyl in Russia) but nowadays there are procedures in place to ensure safety.
• There are problems and dangers, which could lead to accidents. The power stations are all manually run and human error could lead to possible accidents.
• The reactors also have a very expensive capital outlay in the beginning, although the costs are cheaper in the long run.
• The plants do require downtime for maintenance.

4.Hydro Power

WHAT IS HYDRO POWER?

 Hydro power is the process of changing the kinetic energy of flowing water in a river into electrical power that we can use.

HOW DOES IT WORK?

 A dam is built where there is a natural lake or a big river in a valley. The dam is used to hold the water and create pressure so that the water can produce more electrical power. There is gravitational potential energy stored in the water and this energy is used to turn generators and create electricity. These turbines are within tunnels in the dam wall. Electrical generators are turned by these massive turbines and create electricity. Water flows through these tunnels with great pressure and is used to turn these turbines. The water has immense pressure due to the great height at which is kept in the dam. If there is a greater volume of water or there is a very large difference between the water level and where it flows out than you can get more power out of the water as it has greater potential energy. This difference in height of the water is called the head. The generator contains 2 main parts: the rotor and the stator. The rotator is the part which rotates and the wire has a huge magnet inside of it; and the stator is the part which is covered in copper. The electrical current is created when the rotor spins around the copper wire on the stator. This is the charge which is then used as electricity.

IS IT RENEWABLE?

 It is renewable because the process takes nothing away from the environment and therefore nothing needs to be replenished. The water stays in the water cycle and can keep producing energy endlessly.

APPLICATIONS OF HYDRO POWER

 Hydro power is also utilised by large scale companies as a private use. Many large mining companies or aluminium manufacturers use vast amounts of electrical so rather than buying from the state they can generate their own power by using hydro power generation.

ADVANTAGES

• No pollution or waste produced
• Renewable energy source
• Very reliable energy source
• Not expensive to maintain once the dam has been built
• Can increase the plants production or decrease it whenever there is high or low demand
• Water can be stored, waiting to be used in peak times

DISADVANTAGES

• Building the dam is expensive and time taking
• The dam will change the habitat and landscape upstream, as much more land will be submersed
• The land below the dam is also affected as the flow of water is reduced
• Silt can build up in the dam as the water slows down it does not have enough energy to carry the sand and silt which it was

5.Tidal Power
WHAT IS TIDAL POWER? Tidal Power is the generation of electrical power through the harnessing of the ebb and flow of the tides.
HOW DOES IT WORK?
A barrage, which is in fact a huge dam, is built across a river estuary or bay. This barrage has gates in it which allow the water to flow into the barrage with the incoming tide. These gates are then closed when the tide begins to go back out. This water which is now trapped inside the barrage is now called a ‘hydrostatic head’. The greater the head the more power can be generated from the outflowing water. There are other gates within the barrage which are now opened; these gates contain hydro-electric generators, very similar to the ones used in Hydropower. These generators are now turned by the outflowing water and power is generated.
The tidal range has to be sufficient in order for this to be a practical means to generate power. This range should be in excess of 5 metres otherwise the power generated is not sufficient.
The main downfall of tidal power generation is the capital needed at the beginning of the project to construct the barrages and the effect on the environment by the change in the water levels. But once the barrages have been built there is a very low maintenance cost. The generators only need changing once every 30 or so years and there is very little work needed to be done.
IS IT RENEWABLE?
 Yes, the tides will continue to ebb and flow, thus there will always be power being generated. The water is not used up, it stays in the water cycle, and can therefore be used over and over again without the need for replenishment.

APPLICATIONS OF TIDAL POWER
 Small-scale tidal mills were used in the Middle Ages for grinding corn. The barrages which are built can be used as a means to cross the estuary with much greater ease. The main application of tidal power is as an additional means of generating renewable, sustainable energy which does not affect the environment in a negative way.
ADVANTAGES
· It is very cheap to maintain
· There is no waste or pollution
· Very reliable
· We can predict when tides will be in or out
· The barrage can help to reduce the damage of very high tidal surges or storms on   the land

DISADVANTAGES
· It changes the coastline completely and the estuaries are flooded so any mud flats   or habitats that birds or animals live on are destroyed
· Initial building cost is very expensive
· Water is not replenished, it cannot flow away so any dirt or pollution lingers around   the coast much longer
· Silt builds up behind the barrage
· Disrupts creatures’ migration in the oceans
· Needs a very big piece of sea to be cost effective
· Not many sites suitable for this kind of power generation; building the barrage
· Only produces power for about 10 hours of the day6. Biomass

WHAT IS BIOMASS?

 In the developed world biomass is becoming more important for dual applications such as heat and power generation.

 Biomass is a clean renewable energy resource derived from the waste of various human and natural activities. It excludes organic material which has been transformed by geological processes into substances such as coal or petroleum.

 The energy of biomass is extracted from three distinct sources:

Wood Waste Alcohol fuels Crops Landfill gases

 Wood is the largest energy source of biomass: contributors include the timber industry, agricultural crops and raw materials from the forest.

 Waste energy is the second largest source of biomass energy. The main contributors are: municipal solid waste and manufacturing waste.

 Alcohol fuels is the third largest contributor and is derived mainly from corn.

Any source can be used to fuel biomass energy production. We can use rubbish, animal manure, woodchips, seaweed, corn stalks and other wastes. Biomass is matter usually thought of as garbage. Some of the sources are just lying around: dead trees, left-over crops, woodchips, sawdust from lumber mills, even used tires and livestock manure will do.

 In California, USA, more than 60 million tons of energy sources for biomass energy are collected each year. If all these sources were used to create biomass energy, California could make up to 2000 megawatts of electricity. That is enough to make electricity for about 2 million homes.

HOW DOES IT WORK?

 The harnessing of energy from biological mass (biomass) is a simple process. The waste wood and other sources are gathered in big trucks. The waste is then transported to a biomass plant. Here, the waste is fed into furnaces where it is burned. The heat created is used to boil water and the energy from the steam is used to rotate turbines and generators.

 The second method, through which energy is created, is called Landfill Gas. When garbage is burned or is allowed to decompose it gives off methane gas. Pipelines are put into the landfills (pits in which garbage is burned) and the methane gas is collected. It is then used to make energy in power plants.

 The use of biomass can help reduce Global Warming. Plants use and store carbon dioxide (CO2) when they grow. When it burns or decomposes, it releases the CO2. Replanting plants, crops or trees etc. ensures that the C02 is reused. If the plants are not replanted the biomass will disrupt the natural carbon equilibrium and thus continue to contribute towards Global Warming.

IS IT RENEWABLE?

 Biomass is renewable; we are going to carry on making waste products, plants and trees are going to die and the cycle will continue. This ensures that the sources contributing to biomass are always available.

The use of biomass can be environmentally friendly because the biological mass is reduced, recycled and then re-used.

 Innovations and ideas in which biomass can be used are continually being invented. One such way is the production of ethanol, a liquid alcohol fuel. Ethanol can be used in special types of cars that have been manufactured to accept alcohol fuels instead of petrol. This innovation helps reduce our dependence on oil.

APPLICATIONS OF BIOMASS ENERGY

 Biomass energy provides an alternative source of energy. In rural India biomass is used for cooking and agricultural growth. It has been very useful for village households that own cattle. Through a simple process the cattle dung is used to produce a gas which is then used as fuel for cooking. The surplus dung is used as manure.

 The use of sugarcane to produce electricity is increasingly being used in Indian sugar mills: this is being done to clean the environment, cut down power costs and earn additional revenue. After the juice has been extracted from the sugarcanes, the leftover pulp - bagasse - is sold to power plants. Here, the bagasse is burned. The energy produced is then provided to the sugar mills.

 Biomass power plants are becoming very popular. Using resources that are easily available makes the production of energy efficient and reliable.

ADVANTAGES

• Biomass can be used for fuels, power production and products that would otherwise be made from fossil fuels.
• It does not add CO2 to the atmosphere as it absorbs the same amount of carbon in growing as it releases when consumed with fuel.
• It can be used to generate electricity with the same equipment or power plants that are now burning fossil fuels.
• It is sensible to use waste products where we can.
• Biomass fuel generally tends to be cheap.
• Using biomass sources places less demand on the Earth's resources.
• The use of biomass energy has the potential to greatly reduce greenhouse gas emissions.
• The use of biomass can reduce dependence on foreign oil.

DISADVANTAGES

• Collecting sufficient quantities of waste can be difficult.
• Burning the fuel creates greenhouse gases, although only a very little.
• Certain materials aren't always available.

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