Solar electric concentrators with small concentration ratios: field experience and new developments

Based on the experience from PV V-trough concentrators for medium to large scale power stations a new concentrator system (ARCHIMEDES) with passive tracking adapted for small decentralized applications has been developed. The PV receiver is optimized for operation at 2× with standard one sun solar cells. An improved thermohydraulic drive reaches a tracking accuracy better than ±1 deg. The system is designed for efficient water pumping and is in operation and under test in Germany, Spain and Greece since summer 2000 and reached annual PV energy harvests above 3000 kWh per installed kWp. Field test results are reported and the technical and economic potential of PV systems with small concentration ratios is addressed.