Renewable energy is the term used to describe energy flows that occur naturally and continuously in the environment, such as energy from the wind, waves or tides. The origin of the majority of these sources can be traced back to either the sun (energy from the sun helps to drive the earth’s weather patterns) or the gravitational effects of the sun and the moon. This means that these sources are essentially inexhaustible.
The key issue is how to extract this energy as effectively as possible and convert it into more useful forms of energy. This can range from directly using the energy from the sun to heat water to using mechanical devices, such as wind turbines, to convert the kinetic energy in the wind into electrical energy.
Energy underpins virtually every aspect of our economy and day-to-day lives. However, the use of fossil fuels, which currently provide the bulk of our energy, releases greenhouse gases (such as carbon dioxide) into the atmosphere. Due to factors such as population growth and changes in lifestyle, the demand for energy has increased to levels where the burning of fossil fuels is releasing enough greenhouse gases into the atmosphere to begin to directly affect our climate system.
There is now a scientific consensus that climate change is real and that it poses an immense threat to the world we live in. Impacts of climate change will make global problems such as drought, famine, flooding, disease, regional insecurity and population displacements worse, and seriously hinder poor countries’ efforts to tackle poverty.
The UK is currently responsible for the release of around 3% of the world’s global greenhouse gas emissions, despite having only 1% of the world’s population. UK energy industries are the largest single contributors to UK greenhouse gas emissions, contributing over a third (54 million tonnes) of the total amount of carbon dioxide emitted in the UK. 
To help lessen the effects of climate change, we must reduce the level of greenhouse gases emitted. This can be achieved by generating our energy from sources that emit low or even zero levels of greenhouse gases, such as renewable energy. We can also make sure that we use energy as efficiently as possible. However, these are not either/or options.
As well as countering the effects of climate change, using renewable energy will also help to reduce other forms of environmental and social damage arising from the use of fossil fuels. For example, it will minimise the impact of acid rain on water and forest ecosystems, or reduce localised air pollution and its subsequent health impacts.
Another important reason for alternative forms of energy is security of supply. We need to take steps to make sure that the UK continues to have the energy that is vital to its economy. In 2006, 12% of the UK’s gas supply came from gas imports (net of gas exports) 
The energy industry still relies on finite, diminishing sources of fossil fuel such as coal, oil and gas. In 2006, approximately 75% of the UK’s electricity was generated from these three fossil fuel sources, just over 19% from nuclear sources, and just over 4% from renewable sources . 
Using indigenous renewable sources of energy will reduce our dependence on imported fossil fuels and will bring diversity and security of supply to the UK’s energy infrastructure, as well as helping to improve the environment and minimise the impact of climate change.
The UK Government has signed the Kyoto Protocol. The Government’s Climate Change Programme set out its proposals for meeting its target of a 12.5% reduction in greenhouse gas emissions, under the Kyoto Protocol and EC Member States agreements, in the period 2008–12 and seeks to reduce emissions further – to 20% below 1990 levels by 2010.In the 2003 Energy White Paper, Our energy future – creating a low carbon economy, the Government also pledged to cut current carbon dioxide emissions in the UK by 60% by 2050.
As part of its goal to reduce emissions, the Government has set a target for the generation of electricity from renewable energy sources. By 2010, 10% of UK electricity should come from renewable sources. There is also an aspiration to double this by 2020.
To meet the 10% target, approximately 10,000 megawatts of renewable energy will need to be generated. This equates to between 3,000 and 5,000 wind turbines, or two hundred 50-megawatt biomass power stations.
The UK nations have also set targets for renewable electricity.
However, electricity is only a small part of total energy consumption (approximately 18.7% of final consumption in 2006)  and efforts are being made to increase the use of renewable energy for heat production and within transport.
UK renewable electricity generation has increased significantly since 2002 when the Government introduced the Renewables Obligation (RO). In 2006 electricity supplied from RO eligible sources stood at around 4% of the UK’s total electricity, up from 1.8% in 2002 . 
The Renewables Obligation requires all licensed electricity suppliers in England and Wales to supply a specified and growing proportion of their electricity from renewable sources, and provides financial incentives for them to do so. Scotland and Northern Ireland have their own Renewables Obligations that perform the equivalent function