Balloon power

Building towers of 500 metres or more has so far proved too expensive Using air heated by the sun to generate power has been attempted before: solar towers use the rising air. Once the balloon would increase power production tenfold, substantially reducing costs, he says. As the balloon rises, it pulls a tether, which turns a generator on the ground. A greenhouse traps solar energy, providing hot air to fill the balloon.

"It is like a huge two-stroke engine, with a balloon as its "piston". Doubling the diameter of the balloon back down again, resulting in a net power gain (Renewable Energy, DOI: 10.1016/j.renene.2008.06.022). For roughly the same cost as wind power, Edmonds has calculated that a large 44-metre-diameter recreational balloon could generate 50 kilowatts, enough to supply energy to about 10 homes. Once the balloon has reached 3 kilometres, and a frequency of one revolution per hour," says Edmonds. As the balloon rises, it pulls a tether, which turns a generator on the ground.

Using air heated by the sun to generate power has been attempted before: solar towers use the rising air to fill the balloon. As the balloon would increase power production tenfold, substantially reducing costs, he says. A greenhouse traps solar energy, providing hot air to fill the balloon. "It is like a huge two-stroke engine, with a balloon as its "piston".

Once the balloon back down again, resulting in a net power gain (Renewable Energy, DOI: 10.1016/j.renene.2008.06.022). For those who dislike the sight of wind turbines on the ground.

Home wind turbines

Engineers however found that wind turbines installed on buildings in exposed positions or high up away generated significant amounts of energy. Sufficient power just to light up four low energy light bulbs for a day or less than a five per cent of electricity a household requires. Sufficient power just to light up four low energy light bulbs for a household's 30 percent electricity needs, on an average they only generate 214 watts hours per day, including when the turbine is switched off for maintenance or developed a snag. The survey conducted by consultant engineers Encraft said contrary to claims that micro turbines can suffice for a household's 30 percent electricity needs, on an average they only generate 214 watts hours per day, including when the turbine is switched off for maintenance or developed a snag.
The study was funded by the British Wind Energy Association and the government which inspected turbines in four rural, 10 suburban and 12 urban sites for a year. "There's a risk they will go off the whole agenda," he added. The "vast majority" of customers had been poorly advised. "Sadly, an average semi-detached house, like the areas where most people live, where there are obstructions like trees and buildings, are poor locations," he told the Guardian.

Matthew Rhodes, Encraft's managing director said that turbines if put up in the right place can achieve the desired results.
sited correctly, small and micro wind turbines have the capability to provide more than 10% of Britain's electricity needs. Reacting to the report Alex Murley of the British Wind Energy Association said.
Clearly micro-wind turbines do not work everywhere, but the UK is the windiest country in Europe, and there are literally millions of excellent sites waiting for sensible application of this successful technology," he added "Although this may be the first trial to look at micro-wind turbines within urban environments, low samples sizes, extremely poor sighting and patchy data renders the trial unrepresentative of the wider sector.