Roughly £2.3bn has been invested in low-carbon projects since the launch of the UK's Green Investment Bank (GIB).
The bank, which was set up by the Government as an independent organisation to drive investment in green technology, said it had directly committed £635m to projects in the first five months of operation.
The bank has mobilised a total of £2.3bn in low-carbon investments, with almost £3 of private sector money secured for every £1 coming from the Green Investment Bank (GIB), the organisation said.
The investments will save more than 2.5 million tonnes of greenhouse gases a year, the equivalent of taking around one million cars off the road, and generate enough renewable electricity to power 2.3 million UK homes, the GIB said.
"This represents an excellent level of activity and shows the impact we can have in helping the UK towards a greener economy," says GIB chief executive Shaun Kingsbury.
Schemes which have been backed include a stake in an offshore wind farm and a clean energy centre at Addenbrookes Hospital, Cambridge, to reduce emissions and save money.
A local authority-managed recycling centre in Wakefield, West Yorkshire, to reduce the amount of rubbish sent to landfill and harness energy from waste has also secured investment.
"Our mission goes beyond simply investing our own funds; our job is to crowd-in money from other sources,” adds Kingsbury. "I'm really pleased that we've managed to bring in almost £3 of private funding for every £1 we have committed."
Business Secretary Vince Cable says the first five months' results showed the bank was doing what it was set up to do – draw in and not shut out private sector investment.
"I now want to see the bank move on to become a valued and integral part of the UK's financial infrastructure, playing a pivotal role in the financing of our transition to a green economy,” he says. "We must seize the opportunities for jobs and economic growth in this sector before others do."
The Treasury has given the GIB £3bn capital to invest, but the coalition has faced criticism for not allowing the bank to borrow from markets before 2015, and then only if the target for Government borrowing to be falling is met.