Dolan Media Newswires
Minneapolis — As wind-energy companies try to crank out as much power as possible, some utilities are unwilling to accept wind-generated energy because the utilities’ high-voltage transmission lines can’t accept any more power.
“The grid won’t handle it, and (utilities) have to refuse wind power,” said Scott McBride, regional site manager for Texas-based Padoma Wind LLC.
McBride and hundreds of other wind-energy executives gathered in Minneapolis recently for a three-day Wind Resource and Project Energy Workshop, which was sponsored by the Washington, D.C.-based American Wind Energy Association.
As the primary trade group and lobbying arm for the U.S. wind-energy industry, the AWEA has pushed hard for a mixture of tax incentives and energy mandates that would result in wind farms generating 20 percent of U.S. electricity by 2030.
Texas installed 8,000 megawatts of wind turbines in the past year, said McBride, but grid capacity situations caused many Texas wind farms to shut down their turbines about 2 percent of the time.
Including that 2 percent, the turbines’ down-time totals up to 7.5 percent during a year, or about 27.4 generation days, McBride told professionals attending a turbine-performance workshop.
Particularly in Texas, which ranks No. 1 among wind energy-producing states with 8,361 megawatts of wind energy connected to the grid, weather issues and time-consuming repairs to wind turbine gearboxes contribute to times when wind farms are not producing energy. McBride said wind-energy developers should have crews available round-the-clock to repair damaged turbines.
Minnesota, the fourth-ranked wind-energy state, has 1,805 megawatts of wind power plugged into the grid and is home to Xcel Energy Inc., the nation’s No. 1-ranked utility in wind power.
Geographically, Minnesota is a key piece in many plans to build high-voltage transmission lines, connecting wind energy generated from wind-rich North Dakota and South Dakota to Chicago, and from there to heavily populated Eastern markets.
While many wind farms in Minnesota use 1.5-megawatt General Electric turbines, the workhorse of the domestic turbine fleet, most wind farm developers prefer German-manufactured Siemens wind turbines if they can afford them because they are reliable and durable.
Ioannis Antoniou, a measurement engineer for Siemens Wind Power, outlined his company’s efforts to maximize the amount of energy a wind turbine can generate during the turbine-performance session.
To capture more wind, U.S. wind-energy developers should build higher meteorological towers that measure wind speeds before developing a wind farm, Antoniou said.
Seasonal variances in wind speed and power generation, and differences between daytime and generally windier nights must be considered to get the most out of wind farms, he said.