Renewable-energy objectives in Minnesota Statute 216B call for public utilities like Minnesota Power to get 25 percent of their energy from renewable technology by 2025. Eligible renewable technologies include wind, solar, biomass and hydroelectricity. Although Minnesota Power gets about 85 percent of its energy from coal, it does have a head start on renewables, with perhaps 10 percent today from hydroelectric and biomass.
However, Minnesota’s flat landscape offers limited potential for more hydroelectric dams, we are too far from the equator for effective large-scale solar power, and the logistics of hauling low-density biomass limit that option.
That leaves wind for Minnesota Power, especially the wind-swept terrain of North Dakota. Minnesota Power’s first big wind venture is a $180 million wind farm called Bison 1, with 31 turbines and an 83-megawatt capacity. Adding this to Minnesota Power’s 25-megawatt Taconite Ridge wind farm gives Minnesota Power 108 megawatts of wind.
But that number has to be adjusted for the amount of time erratic winds actually produce power. This is called capacity factor. Wind turns itself on and off, tending toward off in summer when demand is highest on sultry, windless, summer days.
In the U.S. in 2009, wind produced 70 billion kilowatt hours at a 26 percent capacity factor, providing 1.75 percent of the nation’s total electrical power. At a generous 30 percent capacity factor, Minnesota Power’s effective wind power will be at about 33 megawatts in 2011. Minnesota Power’s total generating capacity is 1,700 megawatts, which can be adjusted for the 65 percent capacity factor of coal and biomass to 1,100 megawatts.
That puts Minnesota Power at 3 percent wind, just one-fifth of the way toward raising its renewable capacity from 10 percent to 25 percent. Given the cost of Bison 1, plus the expense of transmission lines from North Dakota to Duluth, an investment in the $1 billion range to meet the state statute is likely.
Denmark is the poster country for wind energy, with more turbines per capita than any other nation. Its 5,200 turbines produce 20 percent of Denmark’s total electrical consumption. But most of that variable power can’t be used by the grid at the time it is generated, and it is dumped at a loss to Norway and Sweden. Denmark’s turbines actually provided an average of 8.7 percent of Denmark’s grid power over the past five years, not the 20 percent and more assumed by many.
Texas has three times the wind capacity of any other state. The Electric Reliability Council of Texas, or ERCOT, reported on Aug. 23 a new Texas electricity demand record of 65,776 megawatts. ERCOT also reported that its 9,319 megawatts of wind capacity produced just 650 megawatts during that period, or 1 percent of Texas’ demand.
U.S. Interior Secretary Ken Salazar just approved the largest U.S. wind program, the Cape Wind project, which will place 130 turbines off the coast of Cape Cod. The $2 billion project will receive at least $600 million in taxpayer subsidies. In testimony before the Massachusetts Energy Facilities Siting Board, the developer said that in summer, when winds are weakest, Cape Wind will produce a modest 100 megawatts at a 22 percent capacity factor. This limit is causing Cape Wind to charge at least twice the going rate for its output. U.S. Rep. William Delahunt, D-Mass., said, “Cape Wind will be the most expensive and most heavily subsidized offshore wind farm in the country with power costs to the region that will at least double.”
There is a role for wind energy in our electric future, but it is as a supplement, not as a substitute, for high-capacity coal and nuclear power. Arbitrary legislative standards like Minnesota Statute 216B that ignore economics and technology likely will fail.
Passing laws on paper is easy. Repealing the laws of nature and physics is not as simple.
Rolf Westgard of Deerwood, Minn., will teach a class called, “Energy: From the Gulf spill to the electric car,” for the University of Minnesota Lifelong Learning Program, beginning Jan. 11. He wrote this exclusively for the News Tribune.
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