태양 전지
Solar cell energy conversion efficiencies for commercially available photovoltaics are around 14–22%. Solar cell efficiencies are only 6% for amorphous silicon-based solar cells. In experimental settings, an efficiency of 44.0% has been achieved with experimental multiple-junction concentrated photovoltaics. The US-based speciality gallium arsenide (GaAs) PV manufacturer Alta Devices produces commercial cells with 26% efficiency claiming to have "the world's most efficient solar" single-junction cell dedicated to flexible and lightweight applications. For silicon solar cell, the US company SunPower remains the leader with a certified module efficiency of 22.8%, well above the market average of 15–18%. However, competitor companies are catching up like the South Korean conglomerate LG (21.7% efficiency) or the Norwegian REC Group (21.7% efficiency).