What is alternative energy? Alternative energy is just about any source of non mainstream energy supply. In other words, it is power supplied by things other than
fossil fuels. In general, non
fossil fuel energy is thought to have less of an impact upon the environment than
fossil fuels sources, so they are considered to be more sustainable. What do we mean by sustainable? Sustainable is generally defined both in terms of relatively low CO2 emissions as well as the ability to either renew, or to tap into, an almost infinite energy source. These two features are the hallmarks of an alternative energy source. The key sources for alternative energy, excluding nuclear power are: Geothermal energy Wind Power Biomass Solar power Hydro electrical Power A brief precis of each source is included below. Geothermal Energy Geothermal energy is an excellent source of heat and, b y boiling water to make steam, power in those areas where the earth's crust is thinnest making heat more accessible. It is not really viable where you have to drill down a long way to capture the heat from the earth's molten core. Wind Power The wind's energy can be transferred into electricity by the use of wind turbines. These wind turbines are not fundamentally different from the windmills of old. Their large blades catch the wind and are turned, just like any other windmill. The difference is that these blades turn a shaft that uses magnets to generate electricity. Previously, windmills turned a stone wheel to generate flour from wheat! Biomass This is basically the same method of energy generation as with
fossil fuels. The only real difference being that the fuel has not been
fossilised over millions of years and is from a renewable source (i.e. more can be grown). Just about any form of organic matter can be used as biomass, whether it is animal products, wood products, rubbish or even refined vegetable oils such as oilseed rape or sunflower oil. Many vehicles have been converted to run on bio diesel - which is diesel that has been made from vegetable oils. Solar Power Solar power is probably the energy source that springs to mind when you are asked to name an alternative energy source. It is also the one that is becoming increasingly widespread in its use. You can now buy DIY solar cells and solar panels, that you fit yourself. Solar power, as the name suggests, comes from the sun. The energy is used in one of two ways. Heat energy - A solar panel absorbs the heat from the sun. It transfers this heat to the hot water supply, helping to generate hot water for day to day usage, or heating. Electrical Energy - A photovoltaic cell captures the light energy or photons, to generate electricity. This electricity is usually stored in a battery and the battery is then used to provide electrical power. Hydro Electrical Power In mountainous areas especially, water is a key generator of alternative energy. This is known as hydroelectric power and is commonly generated from dams, and steep water falls. Rather like a windmill but using water instead of wind, hydroelectric power is generated by falling water pushing past turbine blades. This causes the blades to spin, which causes the turbine to generate electricity. Perhaps the key difference between wind and water is that wind speed can be variable. Water flow, on the other hand, tends to be relatively constant. This gives hydroelectric power an enormous advantage, as it can be relied upon as a constant source of electrical energy. Similar techniques are used in the sea, using tidal flows to do much the same task. This is better known as tidal energy, but is fundamentally the same process. In Summary There are numerous other sources of alternative energy, including nuclear power generation, but the above 5 are the key types that are becoming increasingly widespread. In fact, over the course of the next decade, it is likely that these sources will stop being alternative and start becoming mainstream! For more information and articles on alternative energy and a number of other interesting subjects, please visit Howard's site at http://www.puddyshop.co.uk
