Solar Energy

Solar water heating
Solar Power Solar water heating systems are the most popular form of solar energy used in the UK. The system is connected to the hot water system. Solar water heating systems can provide over half of a household's hot water requirements over the year. There are 2 types of solar water heating collector: flat plate and evacuated tubes.

Redfield, Buckinghamshire

Flat Plate Collectors: Solar water heating panels in their simplest form are made from a sheet of metal painted black which absorbs the suns energy. Water is fed through the panel in pipes attached to the metal sheet and picks up the heat in the metal. For the UK climate the pipe work contains non-toxic anti-freeze. The pipes are often made of copper for better conduction. The metal sheet is embedded in an insulated box and covered with glass or clear plastic on the front. The system is usually installed on the roof.

Evacuated Tubes: The evacuated tube system is a series of glass heat tubes grouped together. The tubes are highly insulated, due to a vacuum inside the glass.

The cost of installing a solar hot water system ranges from approximately £500-£1500 for a DIY system, to £2000-£5000 for a commercially installed system. These prices however, are dependent on the size of the system. A typical installation in the UK has a panel of 3m2 to 4m2 with a storage tank of 150- 200L (2m2 for evacuated tubes). However, the optimum size will depend on actual hot water use. This can be calculated using software to simulate system performance throughout the year.

For more information about solar water heating and a list of suppliers, please visit the Solar Trade Association's website at www.solartradeassociation.org.uk

An example of PV, Oxford

Photovoltaic (Solar Electric)
Photovoltaic (PV) or solar electric can offer us all the ability to generate electricity in a clean, quiet and renewable way. The variety of applications for solar electric are numerous. Photovoltaic (PV) cells are used in simple applications e.g. calculators and watches and also for domestic and larger applications. Large PV systems can be integrated into buildings to generate electricity for export to the National grid.

PV applications today are more common place than we might expect. Domestic burglar alarm systems are now fitted with PV panels to charge the battery for the system. In Milton Keynes, parking meters are powered by solar panels. Many leisure activities are today turning to PV panels for back up electricity, including TV, lighting in caravans and nautical instrument.

The daylight needed is free, but the cost of equipment can take many years before receiving any payback. However, in remote areas where grid connection is expensive, PV can be the most cost effective power source.

Shenley Lodge, Milton Keynes

Passive solar
The use of passive solar design is possibly the simplest form of solar energy. Many buildings today are designed to utilise the energy of the sun as efficiently as possible. The location and orientation of the building are all key factors in optimising passive solar design.

Passive solar design can be best applied in new buildings, where the orientation of the building, the size and position of the glazed areas, the density of buildings within an area, and materials used for the remainder of the structure are designed to maximise free solar gains. Designing a property to maximise free solar gain need not add to the price of construction.
Studies on houses in Milton Keynes have shown that low cost passive solar design features and draughtproofing and insulating measures reduced heating bills by 40%. Savings paid back the costs in two years.