The Government-backed institution has been dogged by disagreement within Whitehall about whether or not it should be a bank able to raise its own capital, amid concerns its borrowing could undermine efforts to cut the deficit.
The Chancellor also announced that the GIB will be able to begin operations in 2012, a year earlier than planned.
Simon Allan, renewables director at Plumb Center, said: "The Government has pledged to be the 'greenest' ever which is certainly a positive step for our industry, the economy as a whole, not to mention the planet."
In addition, Chancellor George Osborne indicated that the Government will act to encourage and incentivise take-up of the Green Deal so that it will appeal to households, businesses and prospective providers alike, before it is introduced in 2012.
Other positives for the industry included the changes to the planning system in favour of sustainable development, the carbon floor price starting at £16 which is good news for investment in green energy, and an increase in the carbon tax for office users which could act as an incentive to renovate business premises to make them more energy-efficient.