Consistent support from the government could turn solar energy into the UK's major power source, supplying enough cheap electricity for 18 million homes, a study has claimed.
Such a move would support almost 50,000 jobs across the British solar supply chain by 2030, the analysis by the Centre for Economics and Business Research suggests.
Ground-based solar farms could account for a third of the total solar power in the UK by the end of the next decade, contributing £25.5bn to the economy and cutting all together £425m from the consumers' electricity bills.
The solar farms, which have caused controversy because of concerns about their impact on the landscape, could deliver the financial benefits while only covering 0.2 per cent of the UK's land area – a tenth of the land occupied by golf courses, the report said.
The remaining two-thirds of the 60 gigawatts of solar power that could be in place by 2030 would come from domestic and commercial roof solar panel arrays, the study for the Solar Trade Association said.
The industry has seen prices tumble since 2010, and the report suggests that with stable policies, large-scale solar could become cheaper than constructing new gas plants by 2018, and the cost of solar could fall below wholesale electricity prices by 2024.
As a result of falling prices, which are down to UK efficiencies in operation and installation as well as falling manufacturing costs, the industry's reliance on subsidy has fallen by two-thirds in the last four years, the industry said.
But the government's "unreliable, unstable" policies on solar power, which have seen repeated changes to the subsidy regime, risked stopping the industry becoming cost-competitive, costing consumers more.
It could also stop British companies exporting their expertise, handing the advantage to Germany and Italy in the global export market, the industry said.
Solar industry leaders are calling on the government to drive a stable move away from subsidies by setting clear support under the existing "renewables obligation" system for the next two years.
They also urged ministers to unlock vast potential for non-household rooftop solar schemes by reviewing the "feed-in tariff" payments for larger projects, which are currently not working to incentivise schemes.
And solar should get a bigger share of the total spending the government allows for energy support payments from consumer bills, they urged.
Paul Barwell, chief executive of the Solar Trade Association, said: "The potential benefits of solar for the British economy are immense. British solar is currently right at the forefront of a global wave of investment and innovation.
"However, the government risks bursting the bubble, damaging the industry and holding Britain back, because it keeps shifting the goal posts on support for solar.
"We believe that government support for solar energy should come down gradually, in line with falling costs, until solar electricity is consistently the same price as the market price for electricity.
"Once we have reached that point – what we call solar independence – solar no longer needs any support and will, with time, bring down energy bills. But it will need stable, gradually declining, support to get there."