I had a somewhat romantic notion that when I move I’d be as green as I could with my energy consumption. Central to that idea was solar panels, photovoltaic cells and a small wind turbine strapped to the chimney. They’d provide at least some of the electricity I’d need.

Proper logs in the grate would heat the lounge, and a thermal sink out back would warm my water using the heat locked up in the ground all around us.

Most of those ideas are still viable, but the wind turbine, it would appear, probably isn’t.

The Guardian has been chatting to Donnacadh McCarthy, who satisfies most of his energy requirements using photovoltaic and solar panels, but has found wind turbines to be close to useless where he lives.

“I’ve had my second one for three months now - the first one was vibrating the house too much - and so far it’s powered one energy-saving bulb for around three hours a day,” he says.” It’s created a total of 1.6 kilowatts, which isn’t even 20p worth of electricity.” It’s a far cry from the 30 per cent cut in your electricity bill that B&Q, which started selling home wind turbines in October (”only £1,498″), suggests you could save from its model.

So, an outlay of close to £1,500, for a 20p return in three months. At that rate it’ll take him until June 3879 (or 1872 years) to recoup the initial outlay. Or, to put it another way, if he was to finish paying off the cost of his turbine today at a rate of 20p every quarter, then he must have first incurred the debt during the time of Hadrian’s reign as Emperor of the Roman Empire, in the year 135.