Turbines are eyesores. So why not put them out on the high seas?
Eystein Borgen was 13 when he built his first wind turbine. He taped scavenged aluminum sheets to a bicycle wheel and attached an old bicycle headlamp generator to this makeshift fan. Then he mounted the contraption on the roof of his parents' summer home on the western coast of Norway. With beginner's luck and a strong gust of wind, Borgen brought electric lighting to the place for the first time.
Borgen, 44, is still making wind turbines. His company, Sway, is developing an arresting-looking turbine that will float 20 miles or more out in the frigid waters of the North Sea, where stiff, constant breezes could someday power vast fields of windmills.
Environmentalists have mixed emotions about wind power. It's clean, it's renewable, but people don't want to look at those towers. Also, it's getting hard to find spots for turbine farms in densely populated areas. The 80-turbine Horns Reef wind farm 10 miles off the coast of Denmark enjoys 20-knot winds and produces 160 megawatts at peak power (maybe 65 megawatts on average). But shallow-water projects ruin sea vistas, which is why the 130-turbine Cape Wind project planned for a location 5 miles out from Hyannis, Mass. has not been built.
Borgen's solution: put the windmills farther out, where no one but the whales can see them. "Two thousand windmills would power all of Norway's houses," says Borgen. Such a park would cover 400 square miles, a speck in the vast northern sea. The catch is that the water is hundreds of feet deep, so no ordinary concrete platform will do. Borrowing technology from the offshore drilling industry, Borgen has designed a floating, strawlike mast on which to mount his turbines. These masts will be tethered to the ocean floor by a 3-foot-wide steel pipe called a tension leg. Sway has landed a $30 million investment from Norway's oil-and-gas giant StatoilHydro.
Borgen's mast extends 275 feet above the water and 300 feet below, weighted at the bottom with 2,400 tons of gravel as ballast. Borgen strengthened his narrow structure by adding a brace-and-wire support on the windward side, similar to the wires that stabilize the mast of a yacht. The 180-foot blades go on the leeward side of the mast. To keep the turbine blades facing the wind, Borgen designed a joint at the bottom of the mast that will rotate based on a computer reading of wind direction.
Borgen says his design will lean no more than 15 degrees from vertical even when hit by a 90-foot wave. The entire unit can be built in one of Norway's deep fjords and towed out to sea by one tugboat.
In two and a half years Borgen intends to tow his first test turbine to a location 5 miles off Norway's southwestern coast, in 500 feet of water. He'd better hurry. In January English developer Blue H Technologies towed a nongenerating prototype turbine 11 miles off the Mediterranean coast of southern Italy. Blue H, which uses a platform design more akin to an offshore oil rig, says it could sign on a 90-megawatt project this summer.
The economics of the Borgen design are good but not great. A 2.5-megawatt turbine on level terrain costs about $4 million, including installation but not the land lease. Those numbers are attractive enough; the top four wind turbine producers have delivered 10,000 megawatts of capacity in the past year. A 2.5-megawatt shallow-water turbine costs $5 million to $7 million, according to Michael McNamara at investment bank Jefferies & Co.
Borgen estimates that a Sway turbine will produce at least 5 megawatts and cost $20 million installed, including the price of the 20-mile cable connecting the turbine to land. That turbine is supposed to deliver 22 million kilowatt-hours a year. A similar-size turbine would produce 15 million kwh on land. Amortize the capital costs over 20 years, allow something for maintenance, and this wind juice will cost 9 cents per kwh.
Statoil, Sway's benefactor, isn't sure about Borgen's math and is pursuing its own design to hedge its bet on Borgen. "I think the inventor of this project probably needs a reality check," says Anne Lycke, director of wind energy at Statoil. "We think it's feasible, and think it will operate, but it will be costly electricity."
If Sway's prototype proves successful, Norwegian power utility Lyse hopes to erect a 300-megawatt deepwater wind farm by 2015. Lyse has invested $6 million in the company. "The price may not be the most important thing," says Aarne Aamodt, production manager at Lyse. "The European Union will need to have an economic framework to make new renewable technology possible."
Sway board member Simen Hesleskaug admits deepwater wind could be twice as expensive to tap, but oceans offer limitless scale: "You can produce a lot of electricity."
Poseidon's Pinwheel
Sway's turbine will float in 900-foot-deep water miles from shore, taking advantage of stronger, more frequent winds and generating more electricity than current offshore or terrestrial designs.