All Renewable Energy Sources in Brief

Using energy from sources which cannot be used up – sun, wind, water and waves – supports sustainable development by reducing carbon emissions. This contributes to increasing energy and climate security for many communities across the world.

Renewable energy comes from sources which cannot be used up, such as wind, sun, water and waves, rather than from fossil fuels such as oil and coal.

To Sum Up in Brief:

  • wind
  • biomass
  • solar
  • hydroelectric
  • geothermal
  • wave and tidal

Wind

Wind power is usually generated by wind turbines situated either onshore or offshore. Wind is the third largest contributor of renewable energy in the UK, after biomass and hydroelectric power.

In total, both offshore and onshore turbines currently provide just over 0.3 per cent of the UK’s electricity supply, enough to supply around 400,000 households.

On and offshore wind energy is expected to make up to half of the government’s 10 per cent renewable energy target. This figure might change – BERR has recently announced plans for a vast increase in the number and size of offshore turbines.

Biomass

Biomass is organic material made from plants and animals. It is a renewable energy source because we can always grow more trees and crops, and waste will always exist. It doesn’t include fossil fuels, which take millions of years to create.

When burned, the chemical energy in biomass is released as heat. Wood waste or garbage can be burned to produce steam for making electricity, or to provide heat to industries and homes.

Burning biomass is not the only way to release its energy. It can be converted to other usable forms like methane gas, or fuels such as ethanol and biodiesel.

Solar

Solar energy involves capturing and harnessing the sun’s energy. There are 3 main ways of doing this:

  • passive solar design ensures that a building’s form and fabric captures the sun’s energy and reduces the need for artificial light and heating.
  • active solar water heating converts solar radiation into heat, which can be used directly or stored.
  • solar photovoltaic (PV) panels or solar cells convert daylight into electricity.

Hydroelectricity

Hydroelectricity is electricity generated by water. In a typical scheme, the water stored in a reservoir – often created by damming a river – is converted into energy as it is piped into water turbines. The turbines are coupled to generators to produce electricity.

Hydroelectric power provides about one-fifth of the world’s electricity, supplying more than a billion people.

The UK currently generates about 0.8 per cent of its electricity from hydroelectric schemes – most of which are found in the Scottish Highlands.

Geothermal

Geothermal power – heat stored below the earth’s surface – can be generated as energy using different types of power plants.

There is currently only one geothermal power plant in use in the UK. It has been estimated however, that there are 1,550 large UK industrial sites where heat-pump systems could be installed.

Wave and Tidal

Both wave energy and tidal power involve harnessing the movement and energy contained in the ocean and converting it into electrical power.

Wave

Ocean waves can, in theory, provide an unlimited source of renewable energy. There is tremendous energy in the ocean and in many areas of the world the wind blows with enough consistency and force to provide continuous waves. Wave power devices extract energy directly from the surface motion of waves which can be converted into electricity by wave power machines.

These machines can be positioned either on the shoreline or in deeper waters offshore. There are 2 wave power devices in the UK – the LIMPET (Land Installed Marine Powered Energy Transformer) on the Scottish island of Islay and the Pelamis sea snake at the European Marine Energy Centre in Scotland, where it is undergoing testing.

Other plans include devices in the Orkneys, off northern Scotland, and a development off the north coast of Cornwall.

Tidal

Tidal power exploits the movement of water caused by tidal currents or the rise and fall in sea levels due to the tides. Although not yet widely used, it has potential for future electricity generation and is more predictable than wind energy and solar power.

The technology required to harness tidal energy is well established; however, it remains expensive and there are relatively few applications – around 40 – worldwide.

Last Updated On:13th April 2013

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