In the 1830s, a British astronomer John Herschel used a solar collector box to cook food during an expedition to Africa. Now, people are trying to use the Sun's energy for many other purposes. Besides its continuous supply and advantages, the use of solar energy is increasing. Solar energy is also becoming more and more important because energy from petrol will disappear soon.
Biomass energy or bioenergy ( energy from organic matter ) has been used for thousand of years, ever since people started burning wood to cook food or to keep warm. And today, wood is still our largest biomass energy resource. However, many other sources of biomasss can now be used, including plants, residues from agriculture or forestry, and the organic energy resource. However, many other sources of biomass can now be used, including plants, residues from agriculture or forestry, and the organic component of municipal and industrial wastes. Even the fumes of landfills can be used as a biomass energy source. The use of biomass can also help increase profits for the agricultural industry.
Hydroelectric power is the biggest source of renewable energy, providing 14% of the world's electricity. Fast flowing water released from dams in mountainous areas can turn water turbines to produce electricity. In most cases, water is stored behind a dam in a reservoir. Water pressureforces the water onto the blades of a turbine. Rotation of the generator represents the kinetic energy which is finally transformed into electric energy that will be supplied for public usage. Ocean or tidal waves can a also be used to generate electricity.
Coal is a fossil fuel formed over millions of years from plants. lt is a hard, black coloured rock-like substance made of carbon, hydrogen, oxygen, nitrogen and sulphur. Coal is mainly burned in power stations to produce electricity. When coal is burned, it produces a large amount of carbon dioxide, one of the gases responsible for the greenhouse effect.
Petroleum is a oilly, flammable, liquid solution of yellowish green to black colour, which occur naturally in earth. lt is formed from decomposed plants and animals a long time ago. When distilled, it yields gasoline, kerosene, paraffin, fuel oil, benzene, bitumen and others. These products are used in houses for heating and cooking and in factories as a source of heat energy. They are also used to provide fuel for transport and in power stations. However, their uses, especially petrol and diesel, produce a large amount of carbon dioxide. They also produce other poisonous gases that may harm the environment and people's health.
Natural gas is formed from the remaining of plants, animals and microorganisms that lived millions of years ago. Natural gas is colourless and odourless in its pure form. When burned, it gives off a great deal of energy. Unlike other fossil fuels, natural gas emits lower levels of harmful by-products into the air. Natural gas has many applications, commercially, in your home, in industry and even in the transportation sector.
