Homeowners will be able to get Government-backed loans to pay for energy efficiency improvements under a flagship scheme which launches today.
Ministers said the Green Deal would bring about a revolution in energy efficiency - and provide a much-needed boost to the economy.
Officials at the Department for Energy and Climate Change (DECC) said anecdotal information from suppliers suggested hundreds of households have been assessed for the Green Deal.
But they said precise numbers could not be revealed because they were being collated for official statistics.
Reports had earlier suggested just five assessments had been carried out ahead of the launch, which will see Government-backed loans available for energy efficiency work made available for the first time.
Deputy Prime Minister Nick Clegg said: "The Green Deal will help thousands of homes stay warm for less.
"Those people will benefit from energy saving improvements - and their energy bills will fall.
"The UK green sector is a success story - it is the sixth largest in the world and has a crucial part to play in building a strong economy.
"The Green Deal will support thousands of jobs - not just over the next few years, but in the long-term."
The Green Deal involves having a home reviewed by an accredited assessor, who will look at what upgrades can be made and over what time period energy savings would cover the cost of the work.
Green Deal Providers then quote for the work and households can get multiple quotes for some or all of the work. If they proceed, a Green Deal Installer will carry out the work.
The cost is covered by a loan via the Green Deal Finance Company and repayments are added to the cost of the household electricity bill.
The company has been created as a not-for-profit institution tasked with the costs of the loan as low as possible.
But Ed Matthews, head of fuel poverty campaign group Energy Bill Revolution, said the Government's plan did not go far enough.
"The Green Deal and Energy Company Obligation, will not stop fuel poverty rocketing in the face of high gas prices," he said.
"We call on the Prime Minister to use money from the Carbon Tax to super-insulate this country's homes.
"This will provide households with five times more subsidy to insulate their homes and not add a penny more to energy bills.
"It is enough to eliminate fuel poverty and in time cut bills for everyone. It is the just and fair solution."
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