Today, solar energy provides less than one percent of the world's energy, but that share could grow considerably with the right public policies and continued price reductions.
In fact, according to the International Energy Agency’s (IEA) 2014 technology roadmap, solar could become the world’s largest source of electricity, generating up to a quarter of the world’s electricity needs by 2050. Under the EIA scenario, solar photovoltaic (PV) systems could generate up to 16% of the world’s electricity needs, and concentrating solar power (CSP) plants could provide an additional 11%.
It would take only a fraction of US technical solar potential to meet 4,800 billion kilowatt-hours of electricity that the Energy Information Administration’s (EIA) Annual Energy Outlook 2014 says we'll need by 2040. According to the National Renewable Energy Laboratory (NREL), the technical potential for US rooftop and large-scale photovoltaic (PV) near urban centers is over 3,000 billion kilowatt-hours, while the technical potential for large-scale rural PV projects and concentrated solar power (CSP) systems add another 396,759 billion-kilowatt hours of potential.
While the theoretical potential represents more energy striking the earth’s surface than worldwide energy consumption from all sources combined, it would take trillions of dollars of new investment in solar projects, grid upgrades, and storage technologies for the world to become powered by solar completely.