In 2006 there were over 5,000 grant applications for green energy systems
The number of government grants made to people who want to fit solar panels or other green energy systems to their homes has halved, the BBC has learned.
It comes after the low carbon buildings programme cut the maximum grant on offer from £7,500 to £2,500.
The Renewable Energy Association, which says the programme is failing, has accused ministers of complacency.
But the government says uptake went up considerably last month after the need for planning permission was removed.
Europe's third worst
Figures seen by the BBC show that in 2007, 2,339 grants were made nationwide, compared with 5,104 the previous year.
Britain is the third worst performer in EU for producing energy from renewable sources - 2% of the UK's energy is produced in this way - and it has been told to raise its share to 15% by 2020.
In comparison, Germany has 200 times as many homes fitted with solar photovoltaic power.
But critics say the low carbon buildings scheme has been confusing and stingy, and has provided little incentive for people to go green.
Last month the programme was extended by a year to April 2010 but the £2,500 cap remained.
Andrew Cooper, from the Renewable Energy Association, said: "Government has totally ignored the advice of the renewable energy industry and the blindingly obvious evidence of their own statistics - making a failing programme fail over a longer period is not a solution."
A spokesman for department of Business Enterprise and Regulatory Reform said the scheme now offered many more individuals the opportunity to apply for grants.
He said: "More and more people are applying, in fact last month we saw a total of 293 households successfully applying for a share of £313,000, the largest number since May last year.
"In total, 71 of these were applications for solar photovoltaic (PV) systems on homes, which is around a 100% increase compared to last year's monthly average. We continue to monitor the take up of the scheme."