Minnesota's renewable energy objectives are both arbitrary and impractical

The Renewable Energy Objectives in Minnesota Statute 216B call for public utilities to get 25 percent of their energy from renewable technology by 2025. Eligible renewable technologies include wind, solar, biomass and hydroelectric. The impact of this impractical legislation can be seen by showing its effect on a utility like Minnesota Power, which serves northeastern Minnesota.

Although Minnesota Power gets over 80 percent of its energy from coal, it does have a head start on renewables, with perhaps 10 percent today from hydroelectric and burning biomass. Our flat geography 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, especially the wind-swept terrain of North Dakota.

Minnesota Power's first big wind venture is the $180 million Bison 1 wind farm in North Dakota. Bison 1 has 16 Siemens 2.3 megawatt (MW) turbines plus 15 new technology Siemens 3 MW direct drive turbines. This gives Bison 1 an 83 MW nameplate capacity. Adding this to Minnesota Power's operational 25 MW Taconite Ridge wind farm provides it with 108 MW of wind. But we have to adjust that nameplate number for the percent of time that erratic wind is actually producing power (capacity factor). Wind turns itself on and off, tending toward off in summer, when demand is highest on those sultry summer days without a "breath of air."

Three percent wind, from two farms

In the United States in 2009, wind produced 70 billion kilowatt hours (kwh) at a 27 percent capacity factor, providing 1.75 percent of total U.S. electric power. At an optimistic 30 percent capacity factor, Minnesota Power's wind farms will provide about 30-35 MW during 2011. Minnesota Power's total generating capacity is 1,700 MW, which we can adjust down for the 65 percent capacity factor of its coal and biomass plants to 1,100 MW. That puts Minnesota Power at 3 percent wind from its two farms, raising its renewable capacity from 10 percent to 13 percent.

At least four more Bison-scale wind farms will be needed for Minnesota Power to reach the mandated 25 percent renewables. In addition, for approximately $70 million, Minnesota Power has acquired a 250-kilovolt line to bring wind power from Center, N.D., to its Arrowhead Substation in Hermantown, Minn. Meeting the 216B requirement will mean an investment of more than $1 billion for Minnesota Power.

There are other issues relating to the difficulty of integrating intermittent wind power with delicately balanced power grids. Denmark is the poster country for wind energy, with more per capita turbines than any nation. Its 5200 turbines do produce 20 percent of Denmark's total electric 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. There are no large electric grids with consistent wind power at the 15 percent share being required of Minnesota Power.

Texas has top wind capacity

Texas has three times the wind capacity of any other state. The Electric Reliability Council of Texas (ERCOT) manages the state's electric grids. ERCOT reported on August 23, 2010, a new Texas electricity demand record at 65,776 MW. ERCOT also reported that its 9,319 MW of nameplate wind capacity produced an actual 650 MW during that period, or 1 percent of Texas demand. For all of 2009 Texas wind operated at an 8.7 capacity factor and provided 1 percent of total Texas electricity demand.

Last April, U.S. Secretary of the Interior Ken Salazar approved the largest U.S. wind program, the Cape Wind project, which will place 130 turbines off the coast of Cape Cod. This $2 billion program will receive at least $600 million up front 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 MW at a 22 percent capacity factor. This limit means that Cape Wind has to charge more than twice the going rate to cover its costs.

There is a role for wind energy in our electric future, but it is a supplement, not a substitute for high-capacity-factor coal and nuclear base load power. Arbitrary legislative standards like 216B that ignore economics and technology will likely fail.

Passing paper laws is easy. Repealing the laws of nature and physics is not so easy.

Mr. Westgard is a guest lecturer on energy subjects for the University of Minnesota College of Continuing Education.