Solar Power Village

Envelope Power Greenhouse (EPG) is a light-weight structure covered with a special fluoropolymer foil. The foil is transparent for the full spectrum of the solar radiation including the UV-portion, thus no need for pesticides commonly employed in conventional greenhouses. In addition, the UV-radiation provides the aroma thus greatly improving the quality of the produce. The optical system mounted in the roof of the greenhouse concentrates the direct solar radiation onto receivers thus extracting heat from the greenhouse protecting it from overheating; the heat generated at a high temperature level is captured in vegetable oil as the heat-carrying medium. An insulated pipe system transports the oil to a hot-oil storage tank.

Hot Oil Storage stores hot oil at a temperature of up to 220°C. A tank with 2,000 liters of oil has the capacity to store about 75 kWh of useable heat. This saves about 500 kg (1,100 lbs) of wood used in energy-inefficient fire places. This energy is enough to provide 500 people with heat for cooking, to lift water from wells and to generate electricity for about two to three days. In periods of no sunshine the oil can also be heated up with biomass. The Stirling engine, the cooking stove or the system to generate hot steam for disinfection are all powered by the hot-oil storage tank.

Medium-temperature Stirling engine transforms thermal energy into mechanical work – and this already at temperatures of 150°C (300°F). The Stirling engine provided with 50 kWh of heat energy generates electricity of about 1 kWhe for about 10 hours. The mechanical work generated by the Stirling engine can also be used for corn milling, to pump water or for cooling.

SunPulse is a low-temperature Stirling engine to pump water. It is powered by unconcentrated solar radiation and thus works independent of the hot-oil storage tank. The system pumps about 4m3 (1,056 gal) water from 10m (33ft) depth. Part of the pumping system is a hydraulic ram which in combination with Sunpulse can pump water from up to 60m(197ft) depth.

Water Disinfection Systems can be employed together or on a stand-alone basis. CleanPhoton™ disinfects water with solar radiation in combination with catalytic effective surfaces. UVitt™ is powered by electricity which generates UV-radiation of high intensity for disinfection.