May, 2008

Wind Power in Spain

Continued from Page 2

Building the Machines

Another large wind-farm operator within Spain is Acciona, which is also one the top 10 turbine manufacturers in the world. The company’s renewable-energy portfolio includes photovoltaic and solar thermal energy, small hydraulic systems, biomass, and nearly 5,300 megawatts of wind power.

Acciona’s involvement in turbine manufacturing began in 1994, when EHN (a company Acciona later bought) installed the first wind turbines in the autonomous region of Navarra, beginning with six machines near the capital city of Pamplona. Ever since, the company has worked to make its machines bigger, more efficient, and more reliable while improving their connections to the grid.

One of Acciona’s most significant lines of research involves offshore wind farms, which pose distinct challenges in Spain. The offshore turbines in use or in development today stand in relatively shallow stretches of ocean. But Spain’s coast drops off precipitously, and siting turbines in deep water raises technological problems that have not yet been solved.

The government recently authorized the development of wind power in selected areas off Spain’s coasts and released plans to identify the most promising locations and then work with companies to develop those sites.

Researchers are designing buoys to measure meteorological information in selected areas, boats to service the machinery, and platforms to support the turbines. Platforms with a fixed foundation will work only up to a certain depth, at which point floating platforms, similar to those that support oil rigs, will be necessary. So far there are no full-scale working prototypes of floating wind turbines.

“The foundation is quite expensive—about 30 to 35 percent of the total cost of the turbine,” says Carlos Itoiz, deputy executive director of renewable-technology development at Acciona. “If you mount a small machine, the cost is prohibitive. We need much larger machines to make these systems profitable.”

In addition to working on the infrastructure for such systems—no small task, considering that the equipment must survive the punishing ocean environment and then transfer the power to shore—the company is developing offshore turbines with even more power, along the lines of 5 to 10 megawatts. This work necessitates still more improvements. For instance, current power cables carry energy at 132 kilovolts, but Itoiz says that larger machines and larger wind farms will require cables that can carry 220 to 400 kilovolts.

While Acciona doesn’t design each part of its turbines, “we have to coördinate all of it,” says Itoiz. “We work with an entire network of providers, as basically an extension of our research projects. We don’t develop the cables, but we tell the companies what we need and work with them to design it.” Some Spanish companies that provide those parts nationally and internationally include Ingeteam, which designs and implements the electric and electronic components of turbines, and Coiper/Comonor, which builds turbine towers. Ingeteam had supplied more than 11,000 wind power converter units as of February 2008, accounting for approximately 16 percent of the global market.

Itoiz says that Acciona plans on continuing to pioneer in this field. “Working offshore provides a number of different opportunities for research,” he says. “Wind blows more steadily with less turbulence, so you might be able to use another form of wind-farm control; the speed of the rotors might be higher; you don’t have to worry about noise [as developers must when onshore turbines are placed near homes]. Everything has to be more reliable, because maintenance is more challenging. You have to work on all these aspects to make offshore wind a success.”