The reason is because of risk-reducing financial policies around the world, the agency says, and it applies to locations with both the most favourable policies and the easiest access to financing.

The report underlines how important these policies are to encouraging development of renewables and other environmentally forward technologies.

According to the report, which has the catchy title, The World Energy Outlook 2020, there are four 'pathways' to 2040, all of which see a major rise in renewables.

The IEA's main scenario has 43 percent more solar output by 2040 than it expected in 2018, partly due to detailed new analysis showing that solar power is 20-50 percent cheaper than thought.

The calculation depends on financing figures compared with the amount of output for solar projects. That means that at the same time panel technology gets more efficient and prices for basic panels continue to fall, investors are getting better and better financing deals.

"Previously the IEA assumed a range of 7- 8 per cent for all technologies, varying according to each country's stage of development", explains CB.

 "Now, the IEA has reviewed the evidence internationally and finds that for solar, the cost of capital is much lower, at 2.6 - 5.0 percent in Europe and the US, 4.4- 5.5 percent in China and 8.8-10 percent in India", the report said.