Plastic mounts make for a sunny future

By mounting solar panels in vacuum moulded fixtures designed to sit on flat roofs, it is possible to greatly reduce the capital cost of installing solar power. At a time when conventional energy costs can be expected to continue to mount, while the cost of solar cells continues to come down and their efficiencies go up, solar power is a technology increasing worth looking at. Solion, a small company based in London's South Bank Technopark, has developed a low cost flat roof mounting system called 'Sunmount', which does not require anchorages drilled into roofs, is very easy to install and weighs only 11.75kg/m2 including the solar panels. The panels are simply dropped into the mounts, which are vacuum moulded out of recycled ABS. The mounts are connected to each other by screws, and the edges are sealed with silicon to prevent air getting underneath. Air equalisation slots in the sides of the mouldings ensure that they do not lift in high winds and tests in the Building Research Establishment wind tunnel certify that they can withstand wind speeds of 112mph. Maximum power at European latitudes is produced by panels angled at 30 deg to the horizontal but these mounts are angled at 10 deg, which prevents shading, allowing a higher density of arrays, and reduces wind profiles. The presence of the panels and mounts increases the thermal insulation R-value of the roof, and reduces thermal cycling, increasing roof life. Should the roof need maintenance, the mounts may easily be disassembled and then put back. All solar panels are supplied with 20 years warranty while other parts of the system and installation work are guaranteed for 12 years. A number of schools in the London area have been equipped with the arrays. Those interested in obtaining grants to defray costs should look at latest information from the Energy Saving Trust at www.est.org.uk/housingbuildings/funding/solarpv . While the mounts are designed for use with solar panels made by Kyocera, they could equally be adapted to support other photovoltaic panels, and it should be possible to apply the same principles to supporting solar hot water heating panels. Solion Pointers * Vacuum moulded mounts greatly reduce possible weight or roof damage problems that might arise from mounting solar photovoltaic cells in conventional mountings. * The mounts are certified to withstand wind speeds of 112mph. Advances in solar photovoltaics Solar photovoltaic arrays have come a long way since the 1839, when a nineteen year old Frenchman named Edmund Becquerel found that certain substances produced electricity when exposed to sunlight. In 1954, researchers Pearson, Chapin and Fuller reported 4.5% efficient silicon solar cells. Since then, the best research laboratory results with three junction cells are up at 36% efficiency, the best single crystal silicon cells are at 24%, the best polycrystalline cells are at 20%, with novel thin film technologies not far behind. The latest technology is based on organic polymers and while those trumpeted by Professor Yang Yang are so far only 4.4% efficient, they have the potential to be real cheap to make. The UK receives a solar insolation of 1 to 5kWh/m2 /day. At 5kWh/m2 /day, regularly expected in sunny climes, at a conversion efficiency of 20 per cent, the world energy consumption of around 400 Quad (10 to the power 15 BTUs) or 1.2 x 10 to the power 14 kWh per year, or 3.2 x 10 to the power 11 kWh per day could be generated from an area of around 600 km square.