Consumers could be paying about a billion pounds a year to subsidise green energy projects like wind farms, according to a group of MPs.
Campaigners say the subsidies paid to developers are too large
The Public Accounts Committee said in some cases the government is paying out twice as much as the wind farm companies need to break even.
Fossil and nuclear fuels also receive government assistance.
But the Department of Trade and Industry said the subsidies were essential to develop renewable energy.
In Devon, 22 new turbines are proposed near Ilfracombe and 19 near Okehampton.
The Campaign Against Wind Turbines said it was delighted with the report's findings.
Spokesman Peter Kingdon said: "We're not surprised by the report in any way.
"This small application in north Devon is going to generate about £9m every year for 25 years for the developer and in our mind that's too much money.
"That sort of money reinvested in the South West in other renewable technologies would pay much greater dividends for the consumer."
Devon Wind Power said the level of subsidy was "a matter for the government" and Renewable Energy Systems denied the subsidies were too much.
Spokeswoman Rachel Ruffle said: "I don't think people mind paying a small subsidy for clean, green electricity.
"As more renewable energy schemes are built, then the price will come down.
"People want green electricity because they're concerned about climate change and pollution."