The Minnesota Legislature continues to pass laws forcing the use of intermittent wind and solar energy as replacements for base load coal and nuclear power. The Minnesota Legislature has also maintained the state’s ban on even considering new nuclear plants. It is also pressuring Xcel energy to stop burning coal at the Sherco power plant, the largest in Minnesota.
A practical no emission replacement for Sherco would be a Westinghouse AP 1000 nuclear reactor, like the four being built in Georgia and South Carolina. Nuclear energy advocates point to the clean-air, around-the-clock operation of nuclear plants, as opposed to the harmful emissions from coal-fueled facilities.
Opponents retain old nuclear fears such as the issue of storing spent nuclear fuel pellets. There are reasons the Nuclear Regulatory Commission has approved 60-year operating extensions for 73 of the nation’s 102 nuclear power reactors.
First, the Bureau of Labor Statistics reported nuclear plants average 0.09 serious accidents per 200,000 worker hours, compared to the goal of 2.0 for other U.S. industries.
Second, once amortized, nuclear plants can produce electricity for 2 to 3 cents per kilowatt hour.
Third, U.S. nuclear plants have an uptime capacity factor of about 90 percent, three times more than intermittent wind and solar farms.
Nuclear plants emit water vapor but no greenhouse gases, mercury or acid rain.
The U.S. Navy’s nuclear reactors power vessels reliably and safely as they patrol the world’s oceans. Those naval power facilities were the prototypes for the large-scale reactors that provide nearly 20 percent of U.S. electric demand.
The journal Science noted in an issue: “The electrical grid demands exquisite balance. At every instant, the supply of electricity throughout the system — thousands of power plants, substations and transmission lines — must equal demand. If not, wires overheat, voltage drops and circuit breakers snap open to protect parts of the grid.”
Unpredictable variability is a major reason the federal U.S. Energy Information Administration is forecasting that wind and solar energy will provide only a combined single-digit percentage of our electric energy consumption in 2020, not the 20 percent or more that legislatures like Minnesota’s dream about.
In the future, we can reprocess and separate the approximately 5 percent fission products of the spent fuel capsules that require safe storage, as France does. The remaining 95 percent of spent fuel is uranium and plutonium, which can be recycled into new fuel.
Geologic studies show storage of spent nuclear fuel at Nevada’s Yucca Mountain would be manageable. A Department of Energy review of the site said Yucca Mountain has been free of seismic activity for the past million years. The issues blocking waste fuel storage in Yucca Mountain are political, not geological.
The notion that wind turbines can replace coal and nuclear electric power has no basis in science or experience. Because wind blows intermittently, electric utilities must keep their conventional power plants in spinning reserve, ready to ramp up and down to balance wind output.
There is a role for wind and solar energy in our electrical future, but they are supplements, not a substitute, requiring substantial direct taxpayer subsidies. In 2012, wind and solar energy provided 3.7 percent of U.S. electricity consumption. A number of states, including Minnesota, have passed renewable-energy standards. Minnesota’s standard calls for an impractical wind energy minimum of 20 to 30 percent of electric energy within 10 years.
Passing legislation is quite easy; repealing the laws of physics and nature is not as simple.
Rolf Westgard is a professional member of the Geological Society of America and the American Association of Petroleum Geologists. He teaches classes on energy subjects for the University of Minnesota Lifelong Learning program.