Photovoltaics at the Centre

On the roof of the Wetherdown Hostel we have installed 50 photovoltaic roof tiles. These are arranged in an array of 18.6 sq. metres on the east facing sloped roof. In the brightest sunlight these can produce up to 1,800 watts (1.8kW) of electricity which can be used anywhere on the site.

 The pv panels will generate electricity under a wide range of light conditions, even on a cloudy day they will produce some useful power for the site.

 In 2005 the system generated 1,322 units of electricity (kilowatt hours), a saving of over £90 on the electricity bill. It also avoided the emission of about 0.8 tonnes of carbon dioxide which would have been discharged into the atmosphere by conventional electricity power stations.

Photovoltaic technology is the direct conversion of solar energy into electricity in a solid-state silicon cell.  It the same technology that we often see in solar powered calculators and in the light level detection in cameras.  It should not be confused with solar water heating which involves the sun’s rays heating water in panels somewhat like domestic radiators.

The photovoltaic panels on the roof produce direct current (d.c.) electricity which is wired into an inverter where it is converted to 230 volts alternating current (a.c.) and then fed into the electrical distribution system for the whole site.

The photovoltaic panels are more sophisticated than many systems, as they are designed to replace standard roofing tiles.  They fit directly onto the roof battens, are as weatherproof as a normal roof tile, are visually non-intrusive and have a life expectancy of at least 25 years.  They require no maintenance and have no moving or wearing parts.

The system is produced by Redland Roofing Systems and is pictured above being installed by Sundog Energy Ltd. in July 2004.  The total cost of the project was £16,000 which qualified for a 50% dti Solar Grant.