We meet in a café on a Reading business park. Dale Vince goes for the Keith Richards look: ripped jeans, holey vest, scuffed biker jacket, pierced ear bits. Lean and lithe, only his rumpled features give away his 47 years of age. When he smiles, he has snaggled teeth below, new ones on top.

Twenty years ago, Vince was a hippy engineer following the Peace Convoy, best known for getting a bashing from the police in the Battle of the Beanfield at Stonehenge. Now he sits atop Ecotricity, a group that is rated the seventh-largest retail supplier of electricity in the UK and one of the biggest builders of wind turbines. Vince, founder and owner, could be worth up to £100m. That’s quite a journey.

“Yeah, but I’m simply not interested in selling,” he says softly when I ask him how he would value his business and its 51 wind turbines. “People call, but the conversation never gets as far as numbers.”

Vince runs a power company with a difference. Based in Stroud, employing 170, its generation side makes green electricity from wind turbines, while its retail side sells both green and conventionally produced “brown” electricity, ploughing all profits back into green energy. Vince claims Ecotricity spends more per customer on new, eco-friendly sources of power than all other power firms put together.

It’s easier to do when your brand has only 35,000 consumers, and 3,000 business clients — peanuts compared with rivals like Npower, which has 6m customers — but intriguing given the global push for more green electricity. Ecotricity’s wind turbines, from 40m to 85m tall, are popping up everywhere; there’s one whirring by the café where we meet. And Vince says he aims to have 1m customers eventually. That’s why power giants and the oil companies have run the rule over his eco-empire. So far, Vince is not interested in selling out.

But 2009 will be crunch time as recession bites and consumers seek out the best deals. Ecotricity’s customers are signed on at prices guaranteed to match those of the “big six” energy firms (Npower, EDF, Eon, Scottish Power, British Gas, Scottish and Southern Energy). Cheaper deals, however, can be negotiated with the giants by consumers who bundle services. That means customers of Ecotricity, and rival firms like Good Energy, may already pay a premium to be eco-friendly. Will a downturn dissuade them? Vince shakes his head.

“I think it’s a hiccup,” he says slowly. “This is our time. I have strong views on farming energy, and it’s all coming into the public mainstream.”

He has a point. Many believe petrol engines in cars will soon be replaced by fuel cells, and the race is on to increase non-carbon sources of electricity to power them. “You’ll see wind-powered cars within 20 years,” predicts Vince — meaning cars run on electricity produced by wind-farms. He has a vested interested in saying so: he wants to build those wind farms, and he is also — unusually for an eco-activist — a car nut. His firm is bankrolling a prototype electric sportscar. “0-60mph faster than a Ferrari, proving you can be green and have fun,” he says. “It’s taken us six months and will be on the road in February.”

Yet it has taken mainstream carmakers decades to produce an electric car . . .

“You need a decade to get fuel cells working?” he interjects. “Come on.”

He takes another sip of coffee. Vince is a quiet talker, the faint burr of his Norfolk roots still audible. Yet despite his shy nature, you can tell he likes the attention. It comes with the job — his group has built 12% of the UK’s onshore wind-turbine capacity, and not everyone loves that. Vince has had to defend his cause aggressively against considerable scepticism.

Hence his press ads challenging Sir Richard Branson to talk eco with him, his recent attempt at a land-speed record in Australia in a “wind-powered” car, the constant referrals to his online blog. Only last month he was challenging government to use the money spent on fuel poverty allowances to build the Severn Barrage energy generation scheme.

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