Solar photovoltaics

Abstract ‘Solar photovoltaics’ considers developments in solar technology and their potential contribution to global energy generation. Since the invention of silicon solar cells, it has taken some sixty years for their efficiency to increase to over 20 per cent, and for their cost to fall by several hundred times, to the point where the electricity generated by silicon photovoltaic cells can now be cost competitive with that generated by fossil fuels. It has required considerable development and mass production to achieve this, as the processing of silicon to form a solar cell is complex. Silicon cells now account for about 95 per cent of all solar cells; under development are higher efficiency silicon-perovskite tandem cells. In operation, solar photovoltaic power produces no pollutants, no greenhouse gases, and is a safe way of generating electricity. There are no moving parts, which reduces maintenance, and in Europe, it takes only between one and two and a half years, dependent on location, to generate the same amount of energy as was used in making the solar panels. New generators are increasingly photovoltaic, and distributed generation in residential systems is improving access to electricity across the globe. With massive investment, solar photovoltaics could provide about 40 per cent of the world’s energy demand by 2050.