Energy payback time of the high-concentration PV system FLATCON®

The ecological benefit and sustainability of a new energy technology and its potential to reduce CO2 emissions depend strongly on the amount of energy embodied in the materials and production processes. The energy payback time is a measure for the amount of time that a renewable energy system has to operate until the energy involved in its complete life-cycle is regenerated. In this paper, the energy payback time of the high-concentration photovoltaic system FLATCON® using III–V semiconductor multi-junction solar cells has been evaluated. Considering the energy demand for the system manufacturing, including transportation, balance of system and system losses, the energy payback time turns out to be as low as 8–10 months for a FLATCON® concentrator built in Germany and operated in Spain. The energy payback time rises slightly to 12 to 16 months for a system installed in Germany. The main energy demand in the production of such a high-concentration photovoltaic system was found to be the zinced steel for the tracking unit. Copyright © 2005 John Wiley & Sons, Ltd.