// solar energy

Solar energy can be captured by solar panels or passive solar sun spaces.

There are 2 main types of solar panels:

  * Solar Water Heating collectors absorb the energy from the sun and use it to heat water.

  * Photovoltaic panels transform the solar radiation directly into electricity.

For maximum efficiency, solar panels should be mounted on a south facing roof at a 30 to 45° angle to the horizontal and away from any shadows from trees, surrounding buildings or chimneys.

Solar water heating 

These systems are the most popular form of solar energy used in the UK. The panel 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. Flat Plate Collector 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. The metal sheet is embedded in an insulated box and covered with glass or clear plastic on the front. The hot water is pumped into a coil in your hot water tank and raises the temperature of the water, so that less energy is required to bring your hot water up to the desired temperature. Evacuated Tubes are a series of glass tubes grouped together. The tubes are highly insulated by use of a vacuum inside the glass, so that once the water is heated up, very little heat is lost before the water is pumped down to the hot water tank.

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 a local supplier, contact www.pioneer-uk.com or Tel Andy Smith 0870 486 9750 and mention thet you are part of the Carbon Neutral Biggar project. For more information about solar water heating, please visit the Solar Trade Association's website at www.solartradeassociation.org.uk

Build your own solar panel

If you fancy building your own panels, sign up for Kerr MacGregor's solar panel workshops, where for £150, he will bring all the materials you require and will show you how to build your own DIY solar panel. Email: info@carbon-neutral-biggar.com or Tel John Riley on 01899 229429.STOP PRESS NEWS We our first very successful workshop on 26th Aug. Click HERE to see a short video of the day.

Photovoltaic (Solar Electric)

These panels generate electricity from sunlight using what is known as photo-voltaic cells. These cells are thin glass-like plates of silicon material that produce electricity between the front and back surface when sunlight falls on the front surface. The electricity is produced from the visible portion of sunlight, not the heat part. The more intense the light, the more electricity the solar panel produces. Even under cloudy conditions, solar panels produce electricity although in lesser quantities. These PV systems can be integrated into buildings to generate electricity but tend to need large areas to produce sufficient for most households. For more information about PV and a list of suppliers, please visit the British Photovoltaic Association's website at www.pv-uk.org.uk

Passive solar

The use of passive solar design is possibly the simplest form of solar energy. It simply means building a conservatory type of structure on the south facing elevation of the building and then channelling the heat generated into the rest of the building. Many buildings today are designed to utilise the energy of the sun as efficiently as possible. The location and orientation of the building are key factors in optimising passive solar design. Designing a property to maximise free solar gain need not necessarily add to the price of construction but is key to maximising it's energy efficiency. Some studies have shown that low cost passive solar design features, draughtproofing and insulating measures can reduce heating bills by up to 40%