My single girlfriends ask: where are all the decent men? I've found out - they're in Wales, at the Centre for Alternative Technology, learning to make biodiesel. Ladies, abandon London and head west; real men are not extinct, judging by those seduced from their sheds by the thought of making their own fuel from cooking fat.
The centre, an eco-haven in stunning scenery, is entirely powered by wind and sun. It runs fascinating residential courses every weekend. My course was run by two of the UK's experts in biodiesel, John Hallé and Dan Carter, who run a plant in Oxford and deliver their biodiesel locally.
We focused on making it from used cooking oil that can be bought cheaply from restaurants. It is illegal to throw waste cooking oil down the drains, so restaurants usually pay to have it taken away. What could be more convenient than biodiesel companies taking it off their hands for free?
However, making it yourself is not as easy as it sounds. Oil is reacted with alcohol so it is the same consistency as diesel, a procedure that involves a basic level of chemistry and some dangerous chemicals - you have to know what you're doing. But after an afternoon in the workshop, we were undaunted. "If you can plumb in a sink you can easily do this," said one. I'm as likely to figure out how to plumb in a sink as I am fly to the moon, but for Shed Man the process would be fairly straightforward.
A simpler option is to convert your diesel engine to run on pure cooking oil. Conversion kits are made by a German company called Elsbett, and cost about £1,200.
The biodiesel movement took off during the fuel crisis of 2000, when campaigners furtively bought up huge stocks of vegetable oil from Asda in Swansea, at first raising no suspicions. But this entrepreneurial spirit was nipped in the bud when transport officials caught on and dished out heavy fines.
Although biodiesel is taxed less than regular diesel, the Government still needs to offer more incentives. Ultimately, it is best to avoid the need for any fuel by living close to work and shopping locally. Even if you need to drive, buying locally produced biodiesel will cut carbon emissions, slow global warming and reduce reliance on petrochemical resources.
Sadly, the biodiesel at petrol pumps in the future is likely to have been produced in countries such as Brazil by clearing swathes of rain forest to grow oil palm. Fortunately there are a growing number of small British companies, such as Goldenfuels, which make their own biodiesel from waste cooking oil, and which will deliver it to your door. At the same price as regular diesel, what's not to like?
The next biodiesel course is on 9-11 June in Buckinghamshire ( www.lowimpact.org); Centre for Alternative Technology (01654 705 950; www.cat.org.uk); www.vegoilmotoring.com installs Elsbett conversion kits; see also www.goldenfuels.com