What is Solar Energy? 

Solar power describes a number of methods of harnessing energy from the sun for heat or electricity. Passive solar design in buildings, designed to capture heat from the sun, has been used for centuries. It is increasingly of interest to modern day building designers and householders as the environmental costs and limited supply of other power sources such as fossil fuels are realised. Solar energy is already in widespread use where other power supplies are absent, such as in remote locations and in space.

Solar hot water systems are another familiar technology, and are often found in Mediterranean countries. However, solar hot water heaters can also work well in the UK, and can provide up to two-thirds of a household's annual hot water needs. Several types of system are available, including 'evacuated tube' and 'flat panel' systems.

Solar power can be used to generate electricity through the use of solar photovoltaic (PV) panels, which turn light directly into electricity. Solar PV systems work even on cloudy days, when they can produce up to 30 per cent of the power output of a sunny day. 

Finally there is concentrating solar power (CSP), which focuses sunlight from a large area to create high pressure steam, which can be used to make electricity by powering a turbine. CSP technologies are only suitable for arid, hot places such as North African deserts, but some suggest that in the long-term this electricity could be brought to the UK using high voltage cables.

Difficult as it may be to believe, the Highlands and Islands can exploit solar energy. Despite lower solar radiation levels than other parts of the UK, there is still enough solar heat and sunlight to generate hot water and electricity for most of the year. Even on the cloudiest days, energy comes from indirect sunlight, called diffuse solar radiation.

Solar energy projects tend to be small-scale and are suitable for domestic and civic buildings. Ten new homes in Kingussie - built by the Albyn Housing Association - are kept warm with a solar air heating system. The project now acts as a demonstration location, enabling a wide range of people to get the facts and statistics about solar power and to see for themselves how it works.

Learn more about solar energy with the Key Links panel.

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