Scientists from Delft University of Technology in the Netherlands harnessed energy from the wind by flying a 10-sq metre kite tethered to a generator, producing 10 kilowatts of power. The experiment generated enough electricity to power 10 family homes, and the researchers have plans to test a 50kW version of their invention, called Laddermill, eventually building up to a proposed version with multiple kites that they claim could generate 100 megawatts, enough for 100,000 homes.
Wubbo Ockels, a professor of sustainable engineering and former astronaut who leads the Laddermill project, believes kites are a cheap way to harvest the enormous energy in the wind at a kilometre or more above the ground, where winds carry hundreds of times more energy than on the ground.
Ockels is not alone. Google.org, the philanthropic arm of the Californian web-search company, invested $10m (about £5m) last year in a US kite company called Makani, one of the first awards as part of the organisation’s Renewable Energy Cheaper than Coal programme. The aim of both teams is to tap into high-altitude wind, which is an energy source that is more abundant and reliable than the ground-level wind on which normal turbines depend.
Ken Caldeira, a climate scientist at Stanford University’s Carnegie Institution, has estimated that the total energy contained in wind is 100 times the amount needed by everyone on the planet. But most of this energy is at high altitude. The blades of modern commercial windmills sit around 80 metres from the ground, where the wind speed is almost five metres per second. At 800 metres, however, wind speed rises to seven metres per second, potentially generating considerably more energy.
It would be virtually impossible to build a standard turbine to take advantage of the wind at 800 metres, but kites could easily get to these heights. Furthermore, thanks to the high-speed jet stream, countries such as the UK, the Netherlands, Ireland and Denmark are particularly suited to flying kites.
A kite generates power by pulling on a string attached to generators on the ground. When it has reached its maximum height, it is reeled back down to repeat the process. Using computer models, Furey has worked out that flying kites in a figure of eight pattern means the air flowing over them travels even faster than the ambient wind speed. When a kite needs to be reeled in, it is angled so that it falls out of the sky like a glider, without the need for much power. Ockels’s system uses these flying patterns to maximise the power the kites can generate. He is also looking at extending his basic prototype to use multiple kites that yo-yo: when one goes up, another goes down. Ockels estimates that kites could generate power at less than 4p per kilowatt-hour, which is comparable to coal power and less than half the cost of electricity from wind turbines.
There are many ideas for commercial-scale demonstration projects. An Italian company, Kitegen, has come up with a theoretical design for a system that could generate a gigawatt, as much power as a standard coal-fired power station. Its idea involves flying 12 sets of lines with four 500-sq metre kites on each.
How quickly technology will make it to market depends on how much investors are willing to put in. Ockels said that commercial systems could be operational within five years if the money was made available; otherwise the technology could languish in the lab for a decade or more.
– from www.guardian.co.uk
Who ever is finding new forms of energy, the future is for them. Even though he got the living space, but because of the energy future Hitler invaded middle east. He said who control the middle east they will control the world. Americans proved that. Now the fossil fuel companies are trying to sell the last drop of it. But future will be of renewable, if human race exists.