Clean Electricity

Electricity is the lifeblood of modern life so it is at the centre of green policies and technologies that will enable us to build a more environmentally sustainable way of living. Using clean electricity is one of the most direct and impacting ways to join the efforts to mitigate the effects of climate change. Clean electricity comes from solar, wind, wave, geothermal and tidal power, to name but a few examples. In America, at least 50% of electricity customers have the option to purchase clean electricity directly from their power supplier. Some people may go further and install clean electricity systems that will enable them to live off-grid. Others may choose to generate part of the clean electricity they need and buy the rest from a utility company � in such cases it is also possible to sell excess clean electricity back to the grid.

Clean electricity comes from solar, wind, wave, geothermal and tidal power, to name but a few examples. In America, at least 50% of electricity customers have the option to purchase clean electricity directly from their power supplier. Some people may go further and install clean electricity systems that will enable them to live off-grid. Others may choose to generate part of the clean electricity they need and buy the rest from a utility company � in such cases it is also possible to sell excess clean electricity back to the grid. Wind power is also very popular in many parts of the world, especially in Europe. This source of clean electricity is harnessed by turbines which are placed on strategic locations. Turbine technology has seen great improvements over the last few years � they have become quieter and more efficient � and sometimes turbines are placed on offshore windfarms.

Hydropower is a more traditional approach to clean electricity and it comes with its own environmental toll. In places like Brazil it is the main source of clean electricity. In most cases hydroelectric power comes from the energy generated by dammed water driving a water turbine and generator. The amount of energy generated will depend on the volume of water and on the difference in height between the source and the water's outflow.

Geothermal power is another promising source of clean electricity. It comes from underground hot rocks. Water is pumped down to the rocks in order to produce steam. In some parts of the world, steam comes to the surface naturally and is used to power steam turbines that generate clean electricity.

Other sources of clean electricity that have been attracting interest are wave power, which, quite simply, involves harnessing the power of the ocean�s waves. Tidal power also looks to the ocean as a source of clean electricity. Capturing tidal power requires the construction of a barrage across an estuary, storing water behind it as the tide rises and then releasing the stored water through turbines at low tide.