Harnessing the wind may still sound like a pie-in-the-sky fantasy to many. But it makes more than good business sense to Eddie O'Connor, the man behind the recently approved plans for a wind farm off the Wicklow coast. Who is he and why is he doing this?

Eddie O'Connor nods towards the window of his office. Outside, the tops of tall pine trees are whipping this way and that, playthings of a powerful and, today at least, highly visible force. Harnessing the wind may seem a pie-in- the-sky fantasy: Tinkerbell riding the currents, Don Quixote tilting at windmills. But as far as O'Connor and those in the wind-turbine business are concerned, wind energy is an everyday reality.

His company, Eirtricity, already has around 12,500 business customers in the Republic and has been awarded a licence to develop a €600 million wind farm off the Co Wicklow coast that, when completed, will generate 520 megawatts, which will be a significant amount of electricity for the national grid.

"There's enough wind in the north Atlantic to supply the whole of western Europe with electricity," says O'Connor with another nod at the writhing pines. "At the moment, Europe imports nearly 70 per cent of its energy requirement, and the need is growing. But the fossil resources are almost exhausted. The rate of depletion of fossil resources is five times the rate of discovery, so even if George Bush goes into Alaska, well, fine, he'll use that up and ruin the landscape. But it won't solve anything in the long term."

He settles into a chair, then puts his ankle on his knee and balances a mug of coffee on that in turn. He still looks like a businessman, but when he talks about wind he talks not about strategies, projected profits and capital investment but about currents, waves and ospreys nesting in wind turbines. On the wall above his head a framed sign demands: "Give me the facts."

The way O'Connor sees it, the facts about wind energy are straightforward. It's good for the planet in general, and it can be very good for the Republic in particular.

"We have very strong winds blowing all over the country; great big cyclonic storms bring us this kind of weather. We're told in geography class that the prevailing wind in Ireland comes from the south-west - and that is true 240 days out of the 365.

"But you'd be surprised. It comes from all kinds of places. Sometimes from the east. And in the Irish Sea, there's a good deal of north-south funnelling, because of the Wicklow Mountains."

What made O'Connor - and Eirtricity, half owned by National Toll Roads - think the Irish Sea would be a practical place to locate a wind farm? "We've been looking into it for three years," he says. "Obviously, the winds are much stronger off the west coast, but the sea bed falls away quickly there, so it's too deep to put in foundations easily. We decided to start with the Arklow Sandbanks, because it's near the shore without being too near, it's close to a big electricity substation in Arklow and it's big.

"It runs from Brittas Bay right down to Ballymoney, which makes it 25 kilometres long. There's a four-and-a-half metre tide on the bank itself, so the sea runs in and causes quicksand. It's a very high-energy area. It's also quite dangerous. There have been an awful lot of ships lost there over the years, which explains why the Arklow fishermen are great supporters of the project. They have no love for the Arklow Banks."

Despite all that tidal energy, there appear to be few signs of life on the bank. "It's one of the bleakest places you could find," says O'Connor. "Granted, we've only studied it for two years, but we've spent a lot of money on an environmental-impact survey and there's very little evidence of marine life. No fish, no birds, no sand eels. There are no seaweeds out there and, because of that, the small molluscs and crustaceans which are at the bottom of the food chain can't establish themselves.

"What the fishermen hope is that when we build up to 200 turbine bases, the seaweed will regenerate. That's what has been observed in Denmark . . . a great growth of fish life in the area."

The Danes were the first to take wind energy seriously, developing a prototype machine called the Gedser as far back as 30 years ago. It took much longer for the business world to be convinced of its viability. O'Connor, who studied chemical engineering at University College Dublin and spent many happy years in the ESB - "I started doing maintenance work on power stations and ended up buying fuel for them" - underwent his conversion while he was managing director of Bord na Móna. He left the company after an acrimonious and well-publicised split, but if it weren't for the time he spent there, he might never have developed Eirtricity.

"I really wanted Bord na Móna, as a natural-resources developer, to turn its attention to wind, but there was more to it than a business idea," he says. "I remember hearing about global warming way back, maybe in 1989, and rejecting it totally, thinking: 'How can this be? If it's so, we'll have to change everything.' But it didn't go away. Finally, one of my board members said to me: 'You know, this thing is for real; the evidence is incontrovertible.' So I said: 'Well, if that's so, we'd better redress the balance.'

"While I was at Bord na Móna I was never worried about the bogs as such, because they were all long dead before I came along. Their fate was sealed. But I became convinced that this was a viable option for the future; so when I couldn't do it at Bord na Móna, I did it as soon as I left."

He turns to indicate another framed image on the wall of his office. It's a picture of an old-fashioned windmill. With its squat shape and chunky blades, it looks very different to today's high-tech turbines.

"There were 2,000 windmills in Ireland in the 19th century, but they extracted very little energy," says O'Connor. "The blades were like sails, whereas modern blades are like an aerofoil, very scientifically designed; they're also sited much higher."

All of which makes them more visible and, opponents would argue, more intrusive on the landscape. "Yes, well, there have to be a lot of turbines and they have to be spread out, because if they're too close together they rob the wind from each other," says O'Connor.

But he is adamant that even if you don't much like the look of them, you have to be in favour of wind farms, because we're not exactly up to our necks in renewable, let alone environmentally acceptable, energy sources.

"Wave energy could be one of the big things of the future, but it's very much at a research-and- development stage. There's a lot of talk about photovoltaics, where you have sunlight falling on a panel and turning crystals directly into electricity, but obviously in this country you're not going to be getting too much of that.

"We could do a lot more with combined heat and power. And I'm hearing a lot about biomass; that's where you grow trees, willow and birch and so on, and you use coppicing and burn the wood, release CO² and grow more trees to mop it up. But the science of that, I feel, can still improve quite a bit.

"Until we come up with something better, wind is a great source of energy. It's good for the planet, it's good for the country and it will be good for employment . . ."

AS for the reality of living with wind farms, O'Connor says extensive surveys by the Scottish parliament have turned up interesting results. "The general attitude was: 70 per cent positive, 10 per cent negative and the usual don't-knows. But the most interesting result from our point of view was that, where people had actually lived close to wind turbines, they liked them better. That was a very significant thing as far as we were concerned.

"And there's a good reason why you should like them, because your heart rate drops and your blood pressure drops around wind turbines. They're slow - our most powerful turbine will rotate at about 10 to 12 revolutions per minute - they're graceful, they're not threatening andthey're not making grinding noises.

"And if we still don't like them in 50 years' time but have developed a more efficient form of renewable energy, can't we just take them down again?

"Although," he muses with another glance at the windswept window, "in 50 years' time they'll probably have become national monuments and nobody will be allowed go near them."

For more details on wind energy, see www.eirtricity.ie or www.iwea.com, the website of the Irish Wind Energy Association