BIGGER TURBINES COMING FROM EUROPE

The next big thing in wind: Slow wind, huge turbines
Erik Palm, May 14, 2009 (CNET)

SUMMARY
The next generation of wind turbines will be huge, slow and capable of harvesting significant electricity from even limited wind energy.

The basic concept behind this new capacity is that taller turbines allow for bigger blades and a greater “swept area” from which a productive amount of power can be gathered from even low-energy winds.

Besides allowing for the development of regions with lower wind resources, the big new turbines allow the harvesting of more energy with fewer turbines, opening up more ground space between them for productive use by farmers and ranchers as well as, in undeveloped regions, for wildlife habitat.

Much of the innovation in turbine technology is coming from European manufacturers, driven by the EU’s goal of producing 20% of its power from New Energy sources by 2020 as part of its “Triple 20” which also requires member nations to reduce their greenhouse gas emissions (GhGs) 20% and improve efficiency 20% by 2020.

Europe presently has half the world’s installed wind capacity and wants to build more.

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The U.S. took over world leadership of installed wind capacity in 2008. Tax credits and other incentives came out of the 2008 and 2009 stimulus plans and the Obama administration wants to double U.S. New Energy capacity in the next 3 years. While the U.S. industry continues to break into new high-wind territory, the new technology will allow wind producers to get more bang for their development buck and taxpayers to get more for their incentive buck by building in accessible medium-wind territory.

A quarter-century ago the average rotor was ~18 yards. At present, the average rotor is ~110 yards. In 2000, the average capacity of installed turbines was 0.76 megawatts. In 2007, the average capacity was 1.6 megawatts.

A megawatt provides enough power for 250-to-300 homes.

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Siemens, Vestas, Nordex and GE are among the major manufacturers developing bigger, higher capacity, lower-speed turbine technology.

Siemens predicts the low-wind market will be a third of the wind market in the foreseeable future. Its new SWT-2.3-101 has a 2.3 megawatt capacity and with its 86,000+ square foot swept area, 17% bigger than Siemens’ previous 2.3 megawatt turbine, can serve an estimated 700 homes.

Vestas’ new V 112 has a 3-megawatt capacity and is said to be the world's biggest mass-produced low- and medium-wind turbine. It reduces the necessary windspeed for productivity over Vestas previous 3-megawatt model from 8.9 mph to 6.7 mph and lowers the required windpseed for maximum output from 34 mph to 31 mph.

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COMMENTARY
In the U.S., where the wind industry still has lots of open space to develop, this technological advance is not as crucial as it is for Europe. Europe has so far been the world’s leader in wind development but some nations are running out of sites.

Irish wind industry pioneer and entrepreneur Eddie O’Connor, former CEO of Airtricity and currently the CEO of Mainstream Renewable Power, recently observed in an interview about European developers’ move to offshore development that Denmark, which gets 20% of its power from wind, is allowing no more onshore development for lack of available open space.

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Germany, despite lacking space or coastlines with high winds, was until 2008 the world wind energy leader and is anxious to build more as the emerging technology makes it feasible.

3 factors make bigger turbines possible: (1) Grid operators can efficiently integrate their output, (2) new blade designs allow bigger swept areas without overstressing a turbine’s hardware and (3) new materials allow turbines to be built at lower, more manageable tonnages.

Siemens uses a proprietary manufacturing process to make 53-yard fiberglass-reinforced epoxy blades in one piece to eliminate weaknesses between glued pieces.

Vestas also uses composite materials to reduce weight and has teamed with aerospace expert Boeing to streamline aerodynamics and improve fabrication and design analysis and processing.

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The same 3 factors (technology, blade design, materials) and 1 other impose limits to turbine growth. The other factor is the ability to transport turbine parts to production sites. New flatbed trailer steering mechanisms are now required for moving the blades because of the blades' response to highway wind flows that create handling problems for truck drivers.

Offshore turbines, mostly transported by barge, do not have have such limits. They are now being produced in 5- and 6-megawatt sizes and are expected to eventually be made with 10-megawatt capacities. (To repeat: A megawatt provides enough power for 250-to-300 homes.)

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QUOTES
- Rich Reno, platform leader for 2.5-megawatt turbines, General Electric: "Lower wind-speed turbines certainly open up more land for development…Larger turbines open up the opportunity to get more megawatts out of a given piece of land."
- Victor Abate, renewables vice president, GE Energy: "We see continued growth in Europe, notably because of EU legislation to derive 20 percent of its energy from renewable sources…"
- Andreas Nauen, wind power unit CEO, Siemens: "The new wind turbine will open up many potential new sites for our customers…"
- Reno, GE: "I think 70 meters (77 yards) was a pretty big rotor 10 years ago. Today 110 is out there…Can they grow another 30 meters (33 yards) in 10 years? I think it is possible."