Renewable does not pollute.

Alternative Energy

The term alternative energy refers to energy sources that are naturally renewable and do not pollute.

Solar energy

Solar energy is one great alternative for future energy sources. It is environmentally friendly and is renewable, thus making it an excellent choice as an alternative energy source.

According to The United States Environmental Protection Agency (EPA): 'Enough sunlight reaches the earth's surface every year to produce approximately 1,000 times the amount of energy produced by burning all fossil fuels mined and extracted during the same time period.'

As with most renewable energy systems, the initial costs of setting up these solar energy projects is quite expensive. However, the savings on electricity bills in the long-term should make up for this and year after year, the costs of these solar energy are falling which will make it more affordable and widespread.

Solar energy will also be powering some 70,000 homes and several hundred businesses in Britain soon, after the government announced a £10 million investment into photovoltaic (PV) technologies over the next three years.

Photovoltaic cells provide an unlimited supply of free power by converting sunlight into electricity using modern semiconductors. Vast arrays of these cells will be placed on roofs and walls around the country to provide buildings with a renewable source of energy for lighting, heating and storage. Street lighting and traffic signals can also benefit from this power supply further reducing our dependence on fossil fuels and nuclear energy.

Wind Energy

Wind energy is another one of the most commonly used alternative energy in the world, as they enable electricity to be produced in an environmentally friendly way.

By 1999, there are approximately 749 operational wind turbines in about 40 wind farms in UK. A typical turbine in the UK currently has a rated capacity of 0.66MW and will therefore contribute emission reductions of:

• 1491.65 tonnes of CO2

• 17.34 tonnes of SO2

• 5.2 tonnes of NO_X each year.

One single turbine will also produce enough electricity each year to meet the needs of just slightly less than 400 home. The average wind farm in the UK will pay back the energy used in its manufacture within three to five months, and over its lifetime a wind turbine will produce over 30 times more energy than was used in its manufacture.

Another advantage of wind energy is that the ground, which they are positioned on, can still be used for agricultural purposes, such as sheep grazing. If the turbines need to be taken down one day, there is no damage to the environment and no residues are left behind, therefore causing absolutely no damage to the environment at all.

Hydroelectric Energy

Hydroelectric power stations provide about one/fifth of the world's electricity and in Norway, almost all its energy comes from hydroelectricity.

Hydro-electric power is pollution free and safe once it's up and running, although in creating it there can be tremendous disruption and upset to the environment, animals and nearby residents.

The world's most powerful power station is the Itaipu hydroelectric power plant located on the Pirana River in South America. It generates about 13,320 megawatts of energy, enough to power several cities at one go.