IT IS A SCENE worthy of HG Wells. Hideous, grey metallic monsters - some of them more than 400 feet high - are invading our green and pleasant land. There are literally thousands of them, emitting a deafening hum as their huge heads revolve.

Some can scale our mountains. Others stalk our shores. At night they can still be seen by their flashing red eyes. Soon these hideous aliens will be everywhere.

And yet, in the best traditions of science-fiction, these are not, strictly speaking, aliens at all. Like Frankenstein's monster, they are our own creation. How could mankind have been so foolish? What madman allowed Britain to be overrun by this monstrous new species?

The monsters in question are wind turbines. The madmen responsible for them are our politicians.

And if the people of Britain do not act soon to halt this alien invasion, hundreds of miles of our ancient countryside and shoreline will be disfigured for a generation. This is not the War of the Worlds. It is the War of the Winds.

As I write this, looking out the window of our newly acquired house on the Glamorgan coast and trying to imagine how the 30 turbines due to be built directly opposite will look and sound, I am of course a sitting duck. My opposition, someone is sure to say, is mere "nimbyism".

Surely something has to be done to wean the world off fossil fuels - because if we don't switch to "renewable" sources of energy such as wind, our planet will soon be engulfed by a climatic catastrophe. I agree: Something does have to be done to slow down carbon dioxide emissions. It's just that the construction of 9,000 giant wind turbines is not that something.

The truth is that the Government's commitment to wind power is a huge con being perpetrated in the name of environmentalism. Not only will it do virtually nothing to halt global warming. It will impose majoreconomic burdens on ordinary Britons as tax payers, energy consumers and property owners.

The sole beneficiaries of this misconceived policy will be a few power companies and, no doubt, their friends in high places.

Let's get this straight. I could just about live with Britain's biggest wind farm - 30 giant wind turbines, each 443 feet tall, just three-and-a-half miles away - if I genuinely believed wind power was a viable solution to the problem of global climate change. But the thought that their construction is no such thing - that it in fact represents a new and quite unnecessary form of pollution - makes my blood boil.

The view from Sker Point, west of the pretty seaside town of Porthcawl, is breathtakingly beautiful. On a clear day, you can see across the Bristol Channel to Somerset and Devon. To the west, the Gower peninsula is clearly visible; and beyond it the open Atlantic. The long sandy beaches and rocky promontories here are a delight for walkers. And there few prettier spots in South Wales than the Kenfig and Margam Burrows, which have been designated a "Landscape of Outstanding Historic Interest".

Even United Utilities admit that their wind farm will wreck - sorry, "significantly affect" - what they poetically call the "visual amenity".

A beauty spot near you could be next.

There are already a thousand of the things, mainly at sites in the north of the country. The bad news is that plans currently exist to build 8,000 more - 2,000 on land and a staggering 6,000 around the coast.

Nimbyism aside, my objection is not just that wind turbines are a much more expensive way of generating power than conventional power stations. We could all put up with bigger bills if it meant, in the cant phrase, saving the planet. The key problem is that wind power is so inefficient that it scarcely replaces conventional sources of energy at all.

United Utilities make the typical claim that their Scarweather wind farm will have a total capacity of "up to 108 megawatts" - "enough energy every year to power 82,000 homes, equivalent to a city the size of Swansea".

What's more, the company argues, their turbines "will save just under 6 million tonnes of carbon dioxide [from] being released into the atmosphere". The price tag? A snip at £60m - even if it does last only 22 years.

Well, perhaps not quite such a snip. As the Royal Academy of Engineering has pointed out, coal, gas and nuclear plants produce power for between 2p and 3p per kilowatt hour, compared with 5.4p for land-based turbines. What's more, because of the technical difficulty of building, servicing and transmitting the power from them, offshore turbines are even more expensive, generating power at 7.2p per kilowatt hour.

But that's not all. Wind, in case you hadn't noticed, varies. Sometimes it howls. Sometimes there's scarcely a breath. Modern wind turbines start producing some electricity when the wind reaches a speed of about 8 miles per hour; they perform optimally when the wind hits 33mph, and they cut out altogether at around 56mph. What that means is that any energy supplier wanting to buy power from wind farms must also line up substitutes for those days when the wind is either too weak or too strong.

But hang on: I thought wind farms were supposed to be a substitute for coal, gas and nuclear power stations. Wrong. They can stand in for them only when the wind is not too weak and not too strong but just right. The rest of the time, the more reliable power stations have to step in. This means that the true cost of wind power includes the cost of providing back-up power to compensate for the wind turbines' intermittent output. And guess who picks up these extra costs? Step forward the consumer - not to mention the taxpayer.

This is not a theoretical debate. Other countries are already far further down the eco-friendly path to wind power than we are. In the United States, there are already more than 20,000 wind turbines scattered across thousands of acres of land in no fewer than 30 states, not least progressive California.

Closer to home, the German government says it aims to be the "Wind Power World Power". They already have more than 15,000 wind turbines. If you want to walk through a veritable wind turbine forest, visit the Uckermark region north of Berlin.

But in a devastating report published in March, the news magazine Der Spiegel exposed what it called "The Windmill Madness". What had begun as "the dream of environmentally friendly energy" had turned out to mean the 'highly subsidised destruction of the landscape'.

The figures are hair-raising. The German wind power industry has already received tax breaks worth an estimated 1.1 billion euros just to erect their turbines. On top of that, the "windustry" is guaranteed a price of 8.8 cents per kilowatt hour, compared with the average market price of 3.5 cents. Yet the German grid is now plagued by the unpredictability of wind power generation. In one region, the wind was strong enough to utilise more than half the available capacity on only 36 days of the year - less than one day in 10. On 150 days, less than 10% of capacity was being used. It has turned out that for every megawatt of wind power, the system needs 800-900 kilowatts in reserve from other sources.

Not only are all these costs now being passed on to ordinary Germans in the form of rising electricity and tax bills. An even bigger price is also being paid by home owners next to wind farm sites, where property values have collapsed. The only beneficiaries have been the super-rich Germans who have invested in wind farms because of the huge tax breaks - not to mention the politicians in the industry's pocket.

Are we in the process of making the same mistakes in Britain?

The answer is yes.

Not a single wind farm would be built here were it not for the Government's starry-eyed commitment to increase the share of energy we produce from "renewable" sources from 3.9% to 20% by 2020, with a long-term goal of cutting carbon dioxide emissions by 60% over the next five decades.

The Department of Trade and Industry has decided that nearly three-quarters of the additional "renewable" energy should come from wind turbines.

To ensure that this happens, electricity suppliers are being forced by law to buy a rising proportion of their power from wind farms.

What this represents is a return to the planned economy in the name of environmentalism - a kind of Green Stalinism.

The consequences are the familiar Soviet ones: centralised decision-making and localised devastation. In our case, the inspector's report, drawn up after a public inquiry, clearly recommended against United Utilities' proposal. It was simply ignored by the four-member subcommittee of the Welsh Assembly, who gave the green light.

What is so absurd is that no matter how many wind turbines we build, global dependence on fossil fuels will scarcely be diminished at all.

Indeed, if we are not careful, we ourselves could end up relying even more on precisely the sources of power the Government claims it is against.

Why? Because even as it has pumped money into the white elephants known as wind farms, the Government has been unthinkingly running down the one reliable source of CO2-free power.

Over the next 20 years, all but one of the UK's 16 nuclear power stations will close.

And it will take a lot more than an invasion of 400 foot turbines to compensate for that.

(*) Niall Ferguson, M.A., D.Phil., is Professor of History at Harvard University, a Senior Fellow of the Hoover Institution, Stanford, and a Senior Research Fellow of Jesus College, Oxford. His is the author of "Colossus", "Empire: How Britain Made the Modern World" (which has been adapted into a TV series), "The Pity of War", "Cash Nexus: Money and Power in the Modern World", and "Virtual History: Alternatives and Counterfactuals" (the science of elaborating theories about what might have happened).

Copyright: Niall Ferguson, reproduced by EFN with authorization