Comparison and Evaluation Of Energy Sources

coal fire power stations. The fossil fuel, coal, is burnt in a large furnace, and the boiling tube is placed above it. From this comes steam and water vapour which then powers the turbines, producing alternating current. The rotor, made of large electromagnets, turns at a speed of 3000 revolutions per minute. And then electricity is produced at 22000V, whilst the steam is sent to the cooling tower. But there is a great waste. Using trains and diggers to transport different materials around wastes energy, whilst more is lost in the form of heat energy when the steam is sent to the cooling towers. There are also great environmental costs that are paid as it releases poisonous gases: carbon dioxide and sulphur dioxide.  For the same amount of energy released, coal produces more carbon dioxide than oil, which produces more carbon dioxide than natural gas.  There is no realistic way of preventing the release of carbon dioxide into the Earth’s atmosphere.  The sulphur dioxide produced will also get into the atmosphere and cause acid rain, which can have very devastating effects.  The sulphur can be removed from the fuels before it is burnt but that produces much more expensive electricity.  Overall, this type of energy source is only 35% efficient. The other conventional method that is used is nuclear power. It is extremely similar to the above method, but with a few differences. The steam is made in the nuclear reactor, heated by nuclear fission. Once more, the steam turns the turbines but it instead is sent back into the sea or an estuary. The turbines and generators are identical.  Nuclear fuels do not produce gases which increase the greenhouse effect or which help to produce acid rain.  When nuclear power stations are running well, very little radiation or radioactive material escapes into the surrounding area, but if there were an accident, however, large amounts of dangerous radioactive substances may be released over a wide area.  Nuclear power stations also produce waste, some of which can, and will, stay dangerously radioactive for thousands and thousands of years and so it obviously has to be stored very safely and carefully.  Yet for both energy sources, it takes 12 hours for the generators to reach full capacity, and the electricity can’t be stored without another great loss, whilst more still is lost in pylons and the movement of electricity.