The amount of solar radiation received at the earth's surface depends on geographical location as well as local conditions such as cloudiness and turbidity and will vary according to the season and time of day. Useful solar radiation sources are either direct radiation, scattered radiation or radiation that is reflected from various surfaces. The solar radiation can be converted into electricity by photovoltaics (PV) or into hot water using solar water heating.  

The PV installed capacity in the UK increased from 10.9 MW in 2005 to 76.9 MW in 2009. This will have increased significantly since then following support for PV and other microgeneration technologies  provided through a system of Feed-In Tariffs  introduced in April 2010, which provide householders and communities generating their own electricity with regular payments through their energy supplier.   Solar energy is absorbed by the ground and remains fairly constant the deeper you go. This heat can be harnessed by the use of ground source heat pump and is encouraged by the Government through a renewable heat incentive payment.

Renewable energy fuel use has increased in recent years and in 2011 ‘renewables’ accounted for nearly 10% of electricity generation in the UK.  

Biomass energy makes up over 80% of renewable energy fuel use including sources such as landfill or sewerage gas, wood, waste combustion or plant biomass. Biomass can be used in wood burning stoves, biomass combine heat and power or a biomass boiler. The production of biomass, especially energy crops, has been criticized for the taking over of useful agriculture land and producing crops for other than food production.  

Wind accounts for around 11% of renewable energy fuel use.  It is a renewable source dependent on solar energy. Global winds are caused by differential heating over the earth’s surface, which sets up pressure gradients that leads to a flow of air. This flow of air can be converted to a useful form of energy using wind turbines. Some important factors to remember are that while doubling wind speed increases the power generated by a wind turbine eightfold, doubling the size of the wind turbines only doubles the power. Modern, large, electricity generating turbines are designed to reach maximum output at a wind speed of between 10-15 m/s. Disturbances and turbulence can affect energy output as turbines work best at constant fixed wind speed. Wind turbines start operating at wind speeds of around 5m/s and at wind speeds over 25m/s wind turbines shut down. Although available for urban areas, roof mounted turbines perform best in remote areas with consistent, undisturbed wind.   Other sources of renewable energy fuel use include hydro power and geothermal power.