A sycamore seed design may be set to revolutionize the wind power industry.
British engineers have designed a giant wind turbine called the Aerogenerator that would rotate on its axis mimicking the way sycamore seeds fly.
The Aerogenerator has two arms coming out of its base to form a V-shape, with rigid “sails” mounted along their length. The arms act like aerofoils as the wind passes over, helping to generate lift.
It would measure nearly 900 feet from tip to tip and could generate 20MW or more of power.
Engineering firm Wind Power Limited is developing the Aerogenerator, along with architects at Grimshaw, academics at Cranfield University and Rolls Royce, Arup, BP and Shell.
The first Aerogenerator could be up and running by 2013.
Feargal Brennan, head of offshore engineering at Cranfield University, says “Upsizing conventional onshore wind turbine technology to overcome cost barriers has significant challenges, not least the weight of the blades, which experience a fully reversed fatigue cycle on each rotation.”
“As the blades turn, their weight always pulls downwards, putting a changing stress on the structure, in a cycle that repeats with every rotation – up to 20 times a minute.”
“In order to reduce the fatigue stress, the blade sections and thicknesses are increased which further increases the blade self-weight. These issues continue throughout the device.”
“Drive-train mountings must be stiff enough to support the heavier components inside the nacelle on top of the tower, otherwise the systems can become misaligned and the support structure is also exposed to extremely large dynamic thrust and bending stresses, which are amplified significantly with any increase in water depth.’”
Australia:
Small wind-energy companies fear privatisations of power stations and retailers in New South Wales and Queensland could weaken competition in the electricity market, hindering their capacity to contribute to the federal government’s 20 per cent renewable energy target.
Under the renewable energy target, retailers are required to buy or create enough renewable energy certificates (RECs), each representing one megawatt-hour of emissions-free electricity, to meet an annual target.
But because they are generators as well as retailers, AGL Energy and Origin Energy have tended to get the certificates through wind farms they have built themselves, according to The Australian Financial Review.
As a result, independent wind power companies such as Infigen Energy, Pacific Hydro and Canberra-based Windlab, can have difficulty locking in long-term supply contracts for the certificates they produce. Without a long-term contract, banks will not provide finance for a wind project.
“The reality is you need competition in the market place at a retailer level,” Windlab chairman Roger Price said. “I’d rather see four or five major retailers that are looking to purchase RECs rather than just two which are extremely vertically integrated.”.
UK: Families can earn £900 a year by installing solar panels on their roofs as part of a new Government scheme to pay people to generate their own electricity.
Under the deal, which will start from April this year, households will be paid for electricity fed into the grid from renewable technologies such as solar, wind or energy from waste.
The most attractive rate of return will be on solar panels, which for an average sized three bedroom home could earn households £25,000 over 25 years.
Ed Miliband, the Energy and Climate Change Secretary, expects one in 10 homes will have installed renewable power on their homes in the next decade expects with the number of homes with solar panels alone rising from 10,000 today to 700,000 by 2020.
He pointed out that the payments would be tax-free and a return of up to 9 per cent annually was better than any bank could provide.
However campaigners said the scheme, that will add around £11 on the average household bill by 2020 as electricity companies recoup the costs from everyone, is just another “green tax”.
The deal, called feed-in tariffs, will ensure that any households or building that invest in installing renewable electricity, should be paid a good rate of return. People who currently have solar panels must do a deal with their electricity company. The panels cannot provide a home’s entire energy needs as they only work in daylight and the energy they generate cannot be stored. When they are generating electricity, any surplus goes straight into the national grid.
“The guarantee of getting an income on top of saving on energy bills will be an incentive to householders and communities wanting to make the move to low carbon living,” said Miliband.
“The feed-in tariff will change the way householders and communities think about their future energy needs, making the payback for investment far shorter than in the past.
“It will also change the outlook for a range of industries, in particular those in the business of producing and installing small scale low carbon technology.”
Solar panels get the best rate of return under the feed-in tariff, followed by wind turbines and hydroelectric.
Installing solar panels, which cover a space of around 10ft x 10ft on an average sized roof, will cost around £12,500 but this will be paid back in10 years because the households will be paid £900 per annum, plus making £140 savings on the yearly electricity bill.
Mr Miliband also introduced a renewable heat incentive that will pay households for producing their own heat from woodchip boilers or an air source heat pump. A ground source heat pump, that costs more than £1,000 to put in, could be rewarded with £1,000 a year and lead to savings of £200 per year if used instead of oil.
John Sauven, Executive Director of Greenpeace UK, welcomed the scheme but said rates are still too low for communities to invest in expensive long term schemes like hydro electric on rivers or larger turbines.
“For many families, generating their own clean electricity will be an attractive investment,” he said. “However, the level of ambition set by the government’s Feed-in Tariff is still far too low if we are to reach the full potential of small scale renewables.”
Landowners and farmers are angry that the Government has set the rate for energy generated from waste or anaerobic digestion, that could be installed on many farms, so low.
