The Advantages of Amorphous Silicon Photovoltaic Modules in Grid-Tied Systems

Amorphous silicon (a-Si) technology developed by Energy Photovoltaics, Inc. (EPV) has significant performance and cost advantages over traditional crystalline (c-Si) photovoltaic modules. Testing conducted in warm sunny, as well as cooler and cloudier, climates has shown that a-Si modules typically outperform c-Si modules on a normalized energy basis. The higher performance arises from a more favorable power loss temperature coefficient, and a band gap that facilitates the conversion of blue-rich light. Also, a-Si benefits from a relative increase in power during the spring and summer months due to the thermal annealing of metastable defects. Tandem junction a-Si modules produced by EPV capture these benefits at the lowest reported module cost/watt in the industry. As a result, the energy production cost is lower for an EPV a-Si PV system than for a similarly rated c-Si system. The projected cost reductions for an EPV system, using technology improvements already demonstrated on a small scale, indicate that future EPV systems in Europe will have an installed cost no greater than that of c-Si and an energy cost that is ~20% lower