Join Date: Nov 2004
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The world's fastest wind-powered car?
British engineer Richard Jenkins is convinced his Greenbird will soon snatch the world speed crown for wind-powered cars
Parked in the middle of the Mojave desert, about 35 miles southwest of Las Vegas, surrounded by mile upon mile of dry, cracked earth, the Greenbird looks like the mutant offspring of a beached yacht and an alien go-kart. Yet this otherwordly contraption is gearing up to set a world land-speed record.
Its name was inspired by Malcolm Campbell’s Bluebird cars, which broke the overall land-speed record nine times between 1924 and 1935, but the Greenbird has no V12 engine under its bonnet — it is powered solely by the wind in its slender 26ft-high wing.
Richard Jenkins, the British engineer behind this “supercar”, claims it is capable of speeds in excess of 120mph. The current record speed for a wind-powered car — or land yacht, as they are known in America — stands at 116mph (compared with 763mph for an engine-powered car) and was set in 1999 by a US team. Jenkins plans to smash it by the spring.
“We will succeed,” says Jenkins, 32, from London, “It’s just a matter of time. The Greenbird should easily be capable of 120mph, but part of the challenge is that it is so weather dependent.
“As well as building the ultimate vehicle technically, you need a large number of elements to combine at the same time — sufficient wind and no rain, for a start — and then you have to make sure you have the official people watching you. Otherwise, no matter how fast you go, it won’t count.”
The Greenbird is made almost entirely of carbon fibre. Its vertical wing has been made as narrow as possible to minimise aerodynamic drag and can be moved from side to side to adapt to any slight change in wind direction. It is much like changing the tack of a sail on a yacht, although the movements are much smaller and more precise, says Jenkins.
As well as being the vehicle’s designer and builder, Jenkins is also at the controls. He has to steer it while constantly monitoring the wind, adjusting the wing via a hydraulic lever on the dashboard. “The greater the angle of the wing to the wind, the greater the power,” says Jenkins. “But if you overdo the power you just end up going sideways.
“The wind always gusts as you’re going down the course, and you can’t predict what angle a gust is going to hit you and when. A gust of wind provides a sudden burst of power, but it can be a little bit unnerving because you’re not really in control of the acceleration. So it is, er, reasonably exhilarating.”
Jenkins wears a Formula One-style racing helmet and gloves for protection while at the controls, but without an engine at least there is no danger of the Greenbird catching alight. “People think it will be quiet because there’s no engine,” he says, “but it’s very loud. Because the car is made of carbon fibre, which is very rigid, the noise from the tyres is transmitted straight into the body shell.”
Jenkins was all geared up to make his record-breaking run in September in Western Australia. Then a spate of freak downpours left the Greenbird floating on what had been a dry salt flat and the whole thing had to be called off.
“We have to wait to get the same conditions as the current record holders had in 1999 before we even have an opportunity to compete, and this makes it incredibly difficult,” says Jenkins. “When we can’t set a new record due to the weather, it is not like losing a race, but it is more like an athlete not even being allowed to enter the arena, let alone get on the starting blocks.”
You could forgive Jenkins for running out of patience. He first started working on his wind-powered vehicle in 1999. Back then he was a student at Imperial College London, and his ideas for a wind-powered craft formed the basis of the final-year dissertation for his degree in mechanical engineering.
Most people would then have stuffed the project in a drawer and gone out to get a proper job, but Jenkins just could not let it go. This was the ultimate engineering challenge and he had no intention of abandoning it for the graduate milkround.
“If a vehicle has an engine, you basically know that if you have enough money and you can add enough power, you can reach a higher speed,” he explains. “But with wind power, more wind doesn’t necessarily mean you go faster. The vehicle has to be technically very precise to utilise all the power available from the wind while minimising drag, so it is much more of an engineering challenge.”
In the past 12 months Jenkins has received backing from Ecotricity, a green energy company that manufactures wind turbines and which is hoping to use some of his innovations in future projects. Dale Vince, its managing director, also sees the Greenbird as a good way to raise awareness of his own take on wind-powered vehicles — by which he means electric cars, powered from electricity generated by his wind turbines. “That’s the only way a road car could ever be wind-powered,” says Jenkins. “There’s certainly no chance of the Greenbird ever being roadworthy.”
Before Ecotricity’s involvement, Jenkins had to rely on materials companies, which were willing to help out by giving him old stock to build the various generations of the Greenbird vehicle. There are actually two Greenbirds now, with a combined material worth of about £250,000.
The first is designed to run on dry land, and is the main one pictured above and in our graphic. The second is designed to run on ice and has three skis rather than three wheels. Jenkins is planning record attempts on both surfaces early next year.
Right now, Jenkins is camped alongside the dry-land vehicle — the faster of the two — on the border between Nevada and California, working to perfect his design and with nothing but the Sierra Nevada mountains for company.
The vehicle has been through many hundreds of redesigns during its evolution. An earlier prototype had brakes, but these became clogged up with dirt during a test run, creating drag, and were removed. Jenkins now puts wooden chocks in front of each wheel to keep the vehicle stationary. To start the car, he simply removes the blocks, leaps into the cockpit and off he goes.
The car accelerates slowly up to about 50mph, but then gathers momentum and takes just 8 seconds more to reach 100mph. “The last 20mph are the hardest. You need to keep going forwards and building speed without overpowering the wing and going sideways,” says Jenkins. “When it comes to stopping, there are no brakes, so I have to reverse the wing, to create aerodynamic drag, and gradually slow the vehicle down.”
Having spent nine years of his life working on the Greenbird project, Jenkins senses the world record is very nearly his. But what will he do when it’s all over? “Something more commercial,” he says quickly. “At some point I am actually going to have to go out and earn some proper money.
“But there are other technical challenges,” he adds after a pause. “I started looking at the speed record on water and it would be fun to have a go at that. I pretty much think I know how to do it.”