GE is designing an offshore wind turbine that dwarfs its competitors in both size and power output. The Haliade-X, a 12 MW turbine that will roll off the assembly line in 2021, will kiss the sky at an altitude of 260 meters (853 ft), nearly as high as the Eiffel Tower or the Chrysler Building. Here's how it stacks up to other skyscrapers:
GE says that the turbine's capacity factor - the ratio of how much energy it's likely to generate over a period of time compared to its peak generation capacity - will be 63%. That means that one Haliade-X will crank out more than 180 MWh of energy every day - enough to keep the juice flowing to more than 6000 US households or 16000 European homes. (They're a bit more energy efficient across the pond.)
Higher Altitudes = Higher Wind Speeds
The major factors affecting wind power capacity are the speed of the wind and the area swept by the blades. Of the two, wind velocity has the biggest impact, as the wind power is proportional to the cube of wind speed. Offshore winds in some US coastal regions average 12 m/s at altitudes around 90 meters. Reaching up to 260 meters in the same spot lets the turbine access winds traveling at 13.3 m/s or more. An 11% increase in wind velocity translates into 30% more power from the turbine.
Bigger Area Grabs More Wind
It's great that the turbine reaches those powerful high-speed winds, now how about scooping up more of it? That's where the rotor's swept area comes into play. Compared to the Vestas 164 (once the world's most powerful wind turbine) with its 164 m diameter, GE's Haliade-X rotor covers almost twice as much area, nearly doubling its power capacity.
We've Got Big Blades
The new turbine will be sporting the world's longest blades, and for that, GE turned to engineers at LM Wind Power, who currently owns the blade length record at 88 meters. Haliade-X's blades, at 107 meters in length, are longer than a football field. The blades are made from composite materials that provide strength and flexibility - two crucial characteristics for a machine designed to operate in high winds. To manufacture these monstrous appendages, LM Wind Power developed a modular blade assembly technique, allowing them to create a standard size blade base to which different lengths of blade tips can be attached. This not only decreases the cost of production, it allows the tips to be replaced when better technology comes out, and it provides flexibility for wind farms that use turbines of different sizes.
Wind is the Least Expensive Source of Electricity
Financial advisory firm Lazard conducted a study that compared the levelized cost of energy (LCOE) of various technologies and found that wind power - even without subsidies - is becoming the least expensive way to produce electricity.
Advances in turbine technology, including materials, control systems, and manufacturing techniques, will undoubtedly continue the downward spiral of wind power prices, so it's time for energy companies to dump the dinosaurs and catch the wind - we're gonna see it spin!
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