Dream of a low-carbon, rural idyll getting closer?

By Gerard Wynn

LONDON (Reuters) - The falling cost of renewable energy could fuel a city stampede for the country to exchange clean air for carbon emissions, says Nick Rosen, author of a new book, "How to live Off-Grid".

Rosen runs through a familiar checklist of modern woes and fears, from climate change through to record oil and house prices, and then lists emerging solutions including wireless internet and increasingly competitive wind and solar energy.

"In the long-run it's where society's going... there'll be a rush to exurbia," he says, referring to the rural zone beyond U.S. city suburbs that are still close enough to reach the city centre, and known as the stockbroker belt in Britain.

The idea is you buy a field, wood or building plot -- but don't pay the premium for mains access to water, gas and electricity. You skip that by installing your own solar or wind power, with a diesel generator back-up, and dig your own well.

A quarter of a million U.S. households and 100,000 Britons live off grid, estimates writer and broadcaster Rosen.

Rosen's idea isn't to return to a 1960's-style "green" idealism. He sees off-grid becoming mainstream, and appealing as much to well-off people who want a self-contained, second home.

"The only thing that's stopping an exodus now in Britain is planning permission. But the rules are bending," he says.

Britain says it has no plans to relax strict rules on building homes in the country, but has launched a drive to build 3 million new homes by 2020 and wants all new homes to be zero carbon from 2016.