Who will fix the faucet?

Often, big plans are stymied by implementation hurdles, and when talking clean energy, the biggest block often is scarcity of trained labour.

Plumbers are almost wholly unprepared for the "drastic change" to the way the UK's homes are heated as part of efforts to cut carbon emissions, according to leading engineers in UK.

The engineers were wary of government plans to upgrade homes through its much-vaunted "green deal" policy, which will come into force late this year. Under the scheme, households will be offered loans to improve their properties' energy efficiency.

In a report published on Thursday, the Royal Academy of Engineering (RAE) also warned that government plans for insulation and green energy are not adequate for the changes needed for a shift to low-carbon heating. They called for a massive switch to renewable energy such as solar water heaters and wood-burning stoves to a street by street effort to upgrade insulation in Britain's draughty homes.

The lack of necessary skills among plumbers and heating installers is proving a major brake on the UK's ability to make this switch, the RAE found. The study found examples of inexperienced or underqualified installers causing serious problems. One household paid thousands more than it should have because a heat pump had been wrongly connected - instead of energy bills falling as they had expected, the bills soared from £30 to £250 a month. It cost thousands to fix. In another case cited by one of the study authors, solid wall insulation was badly installed in some old housing stock, causing condensation to collect on the walls and rot floor joists.

About a quarter of the UK's carbon emissions come from heating residential buildings, largely with gas. To meet future carbon reduction targets, the amount of fuel used must come down drastically and millions of homes will have to use new technology such as heat pumps.

Clean energy and energy efficiency measures will require a new crop of trained plumbers and electricians to work on the new system. This is what nations have to give priority to before embarking on grand schemes.