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Bowburn, UK -- Working with a partner, C&A have demonstrated the feasibility of a new solar powered pumping system under UK conditions, with an initial installation on an MoD site which is soon to be followed by a second.
The initial site has a special combination of magnesium rich serpentine rocks whose waterlogged soils have led to a unique range of heath-land habitats with a remarkable array of rare plants and animals that must be protected for the benefit of the nation. A guaranteed water supply was required to provide water for the cattle which graze the conservation area in the summer months. The cattle are critical to maintaining the natural habitat and delicate ecosystem of this conservation area.
Two 30m deep boreholes were sunk in different locations on the 350 hectare site and Sun-Sub solar powered borehole systems were installed. Due to the site’s remoteness and sensitivity, laying mains electric cables was not an option and so the solar powered pumps provide a welcome alternative to fuel burning engines.
Photovoltaic panels produce electricity from sunlight using silicon cells, these have no moving parts so are therefore very reliable. They work well in hot or cold weather. Solar water pumps are designed to utilise DC electric power from photovoltaic panels. They must work during low light conditions at reduced power without stalling or overheating.
Low volume pumps use positive displacement mechanisms, which seal water in cavities and force it upward, lift capacity is maintained even while pumping slowly. These differ from conventional centrifugal pumps which need to spin rapidly to work efficiently. A controller or current booster is used in most solar pumps; this is an electronic device that acts like an automatic transmission, helping the pump to start and not stall in weak sunlight.
Compared with windmills, solar pumps are less expensive and much easier to install and maintain. A GPS tracking array is used to tilt the panels as the sun moves across the sky; this increases the water produced by approximately 30%. At night the panels revert to a horizontal position to reduce wind resistance.
Storage tanks are generally used as reservoirs to gravity feed to several troughs. Control can either be carried out by a float switch situated in the tank or by pressure.
We at C&A believe that this technology has a great future for the right applications and is useable throughout the UK. When supplied with the site location, flow requirements and distances to be pumped we can create accurate forecasts of what can be achieved with this equipment.
Source: http://www.capumps.com/
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