Growth of photovoltaics
Worldwide growth of photovoltaics has been fitting an exponential curve for more than two decades. During this period of time, photovoltaics (PV), also known as solar PV, has evolved from a pure niche market of small scale applications towards becoming a mainstream electricity source. When solar PV systems were first recognized as a promising renewable energy technology, programs, such as feed-in tariffs, were implemented by a number of governments in order to provide economic incentives for investments. For several years, growth was mainly driven by Japan and pioneering European countries. As a consequence, cost of solar declined significantly due to improvements in technology and economies of scale, even more so when production of solar cells and modules started to ramp up in China. Since then, deployment of photovoltaics is gaining momentum on a worldwide scale, particularly in Asia but also in North America and other regions, where solar PV is now increasingly competing with conventional energy sources as grid parity has already been reached in about 30 countries.Projections for photovoltaic growth are difficult and burdened with many uncertainties. Official agencies, such as the International Energy Agency consistently increased their estimates over the years, but still fell short of actual deployment.Historically, the United States had been the leader of installed photovoltaics for many years, and its total capacity amounted to 77 megawatts in 1996—more than any other country in the world at the time. Then, Japan stayed ahead as the world's leader of produced solar electricity until 2005, when Germany took the lead. The country is currently approaching the 40,000 megawatt mark. China is expected to continue its rapid growth and to triple its PV capacity to 70,000 megawatts by 2017, becoming the world's largest producer of photovoltaic power any time soon.By the end of 2014, cumulative photovoltaic capacity reached at least 178 gigawatts (GW), sufficient to supply 1 percent of global electricity demands. Solar now contributes 7.9 percent and 7.0 percent to the respective annual domestic consumption in Italy and Germany. For 2015, worldwide deployment of about 55 GW is being forecasted, and installed capacity is projected to more than double or even triple beyond 500 GW between now and 2020. By 2050, solar power is anticipated to become the world's largest source of electricity, with solar photovoltaics and concentrated solar power contributing 16 and 11 percent, respectively. This will require PV capacity to grow to 4,600 GW, of which more than half is forecasted to be deployed in China and India.