Making the global switch from climate-altering fossil fuels to renewables by 2050 would require an extra US$1 trillion per year, but the bill will be covered by lower energy costs, a Greenpeace report said Monday.
On top of some 600 billion euros per year already earmarked by governments and businesses for investment in renewables, the extra funding would be needed to build enough green energy generators to replace coal-, oil- and gas-fired power stations, it said.
The investment would be more than offset by annual savings of nearly US$1.1 trillion in fuel costs, said the report entitled "Energy (R)evolution", compiled by experts from Greenpeace and the German Aerospace Centre.
Wind turbines, for example, run on a "free" energy source -- the wind, while a power station has to be constantly refuelled with expensive coal or gas.
"Because renewables don't require fuel, the savings... (until 2050) are $1.07 trillion per year, so more than meet the costs of the required investment," said a Greenpeace statement.
The world's nations are seeking to curb rampant emissions of climate-altering greenhouse gas emissions in a bid to slow global warming, but the cost of the transformation is often held up as a major obstacle, especially for poor and developing countries.
"The solar and wind industries have come of age, and are cost-competitive with coal," said the report's lead author Sven Teske of Greenpeace, and warned the fossil fuel industry was "moving rapidly into irrelevance".
"Every dollar invested in new fossil fuel projects is high risk capital which might end up as stranded investment."
The report highlighted that as many as 9.7 million people could have jobs in the solar power industry by 2030 -- more than 10 times as many as today and equivalent to the current number of jobs in the coal sector.
Wind industry jobs could increase tenfold to nearly eight million.
The researchers based their forecasts on UN estimations for economic development and population growth, and assumed the world's energy system would be completely "decarbonised" over the next 35 years.
They also considered rising energy demand in fast-growing Africa and Asia, offset by lower demand in rich nations resulting in a peak of global demand by about 2020.
And the study assumed that renewable energy costs come down as the technology and availability improves.
In the short term, electricity could become slightly more expensive - by about $0.02 per kilowatt hour, said the authors.