Too much money is being spent on wind power that will fail to meet the energy needs of future generations, according to a new report.
The Limits of Wind Power report by the Adam Smith Institute claims Government investment in Britain is misguided.
The right-wing think-tank said wind energy would "never be suited as the lone or primary source of grid electricity due to its variable nature and will not deliver the environmental benefits expected".
But the report has been heavily criticised by renewable energy advocates in the South West, who said wind energy is an "accessible and obvious" way to reduce fossil fuel emissions.
The report, released jointly with the US company Reason Foundation, claimed "wind energy is intermittent and therefore these back-ups are needed to avoid blackouts".
The authors said wind energy requires expensive energy storage facilities or reserve power generation facilities to provide for its users.
The paper argues that the practical upper limit for wind power's contribution to an electricity grid is 10% of the total energy mix – rather than the 2020 aim of 8%-15%.
"Very high wind penetrations are not achievable," said William Korchinski, author of the report. "As wind's share increases, system reliability will be adversely affected disproportionately – unless adequate reserve power is available. That power reserve is expensive and lowers any possible environmental benefits."
Johnny Gowdy, programme director at renewable energy champions Regen SW, said: "No one is saying wind is the sole source of renewable energy. It's in the mix with other renewables types needed to manage the supply and demand of energy.
"Wind turbines have well-proved success in reducing carbon fuel emissions to tackle climate change. Both on and off-shore wind energy is an accessible and obvious way of reducing energy costs."
He said there were less than 140 "meaty" turbines producing at least 250kw of energy across the whole of the South West, including South Gloucestershire.
Mr Gowdy added: "So, the argument that the Westcountry is turning into a pin cushion is slightly exaggerated."
Bob Barfoot, North Devon chairman of the Campaign to Protect Rural England (CPRE), said: "Wind power cannot continue to supply the needs of energy.
"If the wind doesn't blow there is no energy. There will be wholesale blackouts if the Government continues on the path it is going.
"Every time there is a wind turbine application, an opposition group is set-up. People realise they aren't doing any good and they are not stupid enough to believe anything they hear."