The blades windmill merrily above the treetops, lording it over the rural skyline like some freak botanical experiment.
Get closer and you can hear them humming quietly as they perform their modern-day alchemy: turning gusts of wind into electricity.
The sight of a 200-foot-tall turbine in the English countryside comes as a surprise. Just 79 wind farms dot the country, providing less than 1 percent of energy needs.
But that is about to change after the government signaled recently that it plans to revolutionize the energy-supply picture in Britain.
Hundreds of new wind turbines, both inland and offshore, are to be built in the coming years as part of a grand design to generate 20 percent of energy from so-called "renewable" supplies by 2020. This, it is hoped, will set Britain on the way to cutting carbon emissions far more radically than the Kyoto agreement calls for: Where Kyoto prescribed an 8 percent reduction by 2010, Blair now is aiming at a 60 percent cut by 2050 - and he wants the EU, including its newest members, to commit to the target as well.
As of 2000, Scandinavian countries led Europe in the use of renewable energy. Sweden, for example, relies on "green" energy sources for 32 percent of its power.
Britain's plan has raised hopes and eyebrows in equal measure. Environmentalists have naturally welcomed it, but criticized a lack of concrete policy proposals to help bring about the shift.
"It is frustrating that the government doesn't have the nerve to commit to formal targets for renewable energy and energy efficiency," says Alex Evans, a research fellow at the Institute for Public Policy Research think tank.
Economists say the move will increase energy costs to the British consumer because of the expense of new technology. The government says it would cost between 0.5 and 2 percent of the GDP in 2050 to achieve the 60 percent emissions goal.
For Prime Minister Tony Blair, however, the issue is bigger: Global warming caused by fossil fuels, he argues, is part of a cycle of degradation, poverty, and bitterness that makes the world a less secure place.
Tackling climate change is as important as tackling terrorism, he says, in an implicit challenge to the skeptical United States to get serious about cutting greenhouse gases.
"There can be no lasting peace while there is appalling injustice and poverty," Mr. Blair said in unveiling the initiative earlier this spring. The same Kyoto pact which the US said went too far did not go far enough, Blair insisted, as he bemoaned the foot-dragging, "especially in some of the world's most powerful nations."
Energy diversity can also help Britain and the US cut dependency on foreign hydrocarbon supplies - an argument that has particular resonance at a time when the Iraq crisis has reminded Americans how reliant they are on Middle East energy resources.
Britain, now a net exporter of oil and gas from the North Sea, is expected to become a net importer of gas from 2005 and of oil from 2010.
"Currently the UK does only 3 percent of power generation from renewables, but we are obviously looking to increase that substantially," a government spokesman said.
Though Britain has some of the biggest tides in the world, underwater wave and tidal power technology is still in its early stages. Solar power looks expensive and is also difficult to store. Hydroelectric power has little room for growth because of public opposition to new dams. Which leaves wind power.
Some 1,000 turbines provide enough electricity to power 400,000 homes in Britain, one of Europe's windiest countries.
While residents of Swaffham, about 100 miles northeast of London, seem ambivalent toward the whup-whupping rotors within their earshot, critics of wind power nationwide are growing increasingly bitter, campaigning against wind farms as a blight on the countryside that will dim its traditional appeal to tourists.
John Stoneman, head of the Save our Skyline lobby group, adds that the wind is an unreliable source which "has to blow at certain speeds to get [the blades] running. Then anything over 45 miles per hour and you have to shut them down because they become unstable."
Alan Raymant, head of renewable energy at Powergen, a big energy supplier, says that to hit government targets, wind farm output would have to increase 16-fold over the next seven years. That's a lot of turbines.
"We don't believe you can get to those targets solely on wind," says Mr. Raymant. "Most people accept the benefits of renewable energy in a broad sense, but they don't want wind farms anywhere near their back garden."
Offshore construction is increasingly being viewed as a solution, and several developments are already under way, he says, "but it is more expensive, more complex, and you have to bring the cables back to shore, which is more costly."