Life Cycle Analysis carried out at the Heat Transfer and Environmental Engineering labs in Greece show that “the conversion of solar energy to electricity using photovoltaic solar cells is less efficient” than using fossil fuels.
Producing PV materials, operating the systems and end-of-use recycling have a greater impact than using non-renewable energy.
There are several factors to evaluate further. Life Cycle Analysis does show that a large enough area of solar cells would outstrip the net impact of the fossil fuel system. [story]