Solar technologies could generate more than a quarter of the world's electricity by 2050 removing up to six million tonnes of carbon dioxide, about the amount generated by all the world’s transport, the International Energy Agency said.
The agency predicts photovoltaics could contribute 16 per cent to the overall energy mix with solar thermal electricity systems, using concentrated Sun rays to heat fluids to drive electricity turbines, adding another 11 per cent.
According to the prediction, more energy could be generated by the mid-century by the solar power installations than by nuclear or fossil fuel power plants.
However, to achieve the large-scale deployment of solar power governments need to set clear, credible and consistent signals about solar, including long-term targets for PV deployment and predictable incentives, the IEA said.
A "roadmap" report from the IEA on solar photovoltaics (PV) said that since 2010 the world has installed more of the technology than in the previous four decades, and that the price of PV systems had fallen by two-thirds in most markets in just six years.
A separate roadmap on solar thermal electricity (STE) said that although the systems had the advantage of being able to store thermal energy to produce electricity later, for example in the peak evening hours after the Sun had set, deployment of STE systems stilled lagged behind PV technology.
In 2014, there were only four gigawatts of STE installed worldwide, compared to 150 gigawatts of PV. However, the report said, new markets for STE are already opening up in the Americas, Australia, China, India, Middle East and Africa.
"The rapid cost decrease of photovoltaic modules and systems in the last few years has opened new perspectives for using solar energy as a major source of electricity in the coming years and decades,” said IEA executive director Maria van der Hoeven.
"However, both technologies are very capital intensive: almost all expenditures are made upfront. Lowering the cost of capital is thus of primary importance for achieving the vision in these roadmaps."
According to van der Hoeven, clear signals are needed to provide confidence to investors to build new facilities, which would afterwards operate with minimum cost or maintenance.
"By contrast, where there is a record of policy incoherence, confusing signals or stop-and-go policy cycles, investors end up paying more for their investment, consumers pay more for their energy and some projects that are needed simply will not go ahead."