Suppliers of mini-wind turbines and solar panels for the home have reported falls of up to 90 per cent in customer enquiries after the Government cut subsidies in May.

While Energy minister Malcolm Wicks and Conservative leader David Cameron struggle with the vagaries of the UK's planning system (see below) to get their wind turbines erected, fewer ordinary households are now even bothering to apply.

Energy experts said that the UK had no chance of meeting the European Commission target of generating a quarter of its energy from renewables by 2020 without a massive roll-out of these green "micro-generators" in the home.

The Renewable Energy Association (REA) said that its members had reported falls of 70 per cent in enquiries from customers wanting to buy or install solar panels or wind turbines.

Rajiv Bhatia, head of renewable energy supplier Alternergy, said enquiries were down by 90 per cent since the cut in grants.

Mr Bhatia said: "The point is that this whole system is not working. Tony Blair said the UK was leading the world when it comes to emissions and green house gases but I don't see that from where I'm standing."

Last year the Government launched the three year Low Carbon Buildings Programme to subsidise microgeneration for households and public buildings. Some £18m is available for households with £50m earmarked for public buildings. But to date, just under £5m has been spent on 2,812 projects in the UK.

The amount handed out is likely to fall further after the Government reduced the level of grants in May. Households can now only receive a maximum of £2,500 for the installation of solar photovoltaic, instead of £15,000 previously. To install a 3.5kw solar PV system for an average house typically costs £20,000. The grants available for wind turbines was also halved to £2,500 although the handouts for solar water heating and ground source heat pumps were not changed.

The other change to the funding programme was to stop the previous monthly allocation of grants which typically ran out within hours of their becoming available.

And even the few grants which are awarded still need planning permission for the installation to go ahead and for the money to be spent. While 2,812 projects have received funding, another 4,460 are awaiting planning approval.

With under two years of the programme left to run, Philip Wolfe, chief executive of the REA, said he feared that the Treasury would take away any unspent money at the end of the programme in two years time.

"The amount available for grants is absolute peanuts in relation to other countries like Germany, Italy or Spain," he added.

In some areas, such as London, it seems to be much harder to get planning approval, as Mr Wicks and Mr Cameron have found out to their cost. Since the scheme launched just over a year ago, 35 applications for mini-wind turbines were made. Sixteen - less than half - were earmarked grants and, of these, only two have actually been built. In contrast, in the South West, 58 mini-wind turbines have been installed.

A spokesman for the department of Business, Enterprise and Regulatory Reform said: "The changes brought in since the re-launch were designed to give a more even spread of support to the various technologies and that is exactly what has happened. We have been pleased to see a steady flow of grant applications and as we have done throughout the programme we will continue to monitor progress."