From sacred cow to white elephant is a short jump. Wind power, once seen as the eco-friend

ly cure-all for Britain's energy problems, is attracting unprecedented criticism. The latest campaign, which unites veteran greens and the opposition Tories, opposes a proposed installation of 27 wind turbines next to Romney Marsh in Kent, a noted bird sanctuary and beauty spot. Hundreds more are planned elsewhere—many in beautiful bits of the countryside where some of Britain's richest people happen to live. A bunch of media-savvy local organisations is now lobbying hard to stop them.

The government remains unmoved. It calls wind power "the most proven green source of electricity generation" and cites Denmark as a role model. Renewables (mostly wind) account for 20% of electrical generation capacity there. Renewable energy is needed both to cut CO2 emissions, promised under the Kyoto treaty, and to reach the government's own target of generating 10% of British electricity from renewable sources by 2010. The cost of this to the taxpayer is likely to be ￡1 billion a year by 2020.

But as well as Tories, toffs and country-lovers, many others think that wind power is seriously flawed. The first big problem is that it is too expensive. Although the British Wind Energy Association puts the cost of electricity from onshore wind farms at 2.5p per kilowatt-hour, only slightly more costly than other power sources, the Royal Academy of Engineering claims that on a more realistic view of construction costs it is much dearer (more expensive): 3.7p when generated onshore and 5.5p offshore.

The government has tried to bridge this gap with tradable certificates. The wind-gatherers gain one of these for each megawatt-hour they generate. Power distribution companies then buy them as an alternative to paying the fines levied for failing to buy a set proportion (currently 4.9%) of renewable energy annually. But a recent House of Lords report noted a big snag: the nearer the industry gets to meeting the government's targets, the less the value of the certificates; once the target is passed, their worth falls abruptly to zero.

So the certificates, which will cost consumers a cool ￡ 500m this year and will be even more expensive next year, cap the supply of renewable energy instead of encouraging it. In effect, firms will buy only the minimum amount of renewable energy necessary to comply with the law.

Then there are the engineering problems. Too light a breeze means no power; too strong a gale and the turbines shut down to prevent damage. Even the wind-lovers expect that the farms will manage only 30% of their full capacity on average. Worse, that output can fluctuate rapidly—by up to 20% of the total national wind capacity in the space of a single hour, according to Hugh Sherman, an energy consultant, who has studied Denmark's wind industry. Furthermore, in a typical year like 2002, he says, there were 54 days when the air was so still that virtually no wind power was generated at all.

But whereas Denmark can import power from Norway and Germany to keep the lights on during calm periods, Britain's power grid is not set up for imports. So conventional coal-, oil- or gas-fired power stations would have to be kept running, ready to take up the load. That sharply raises the real cost of wind energy and means extra CO2 emissions.

Ministers may be right when they argue that wind power is the only renewable energy source that has even a theoretical chance of meeting the government's targets. Given the costs and technical uncertainties, perhaps it would be better to abandon those targets altogether.

Explain the statement "from sacred cow to white elephant is a short jump". (Para. 1)