Local view: Nuclear power must be part of energy solution
The recent climate change report from the National Oceanic and Atmospheric Administration states that many global-warming effects are already here. Alaska's average temperature is up 6.3 degrees since 1950. Winter temperatures in the Northeast ar...
The recent climate change report from the National Oceanic and Atmospheric Administration states that many global-warming effects are already here.
Alaska's average temperature is up 6.3 degrees since 1950. Winter temperatures in the Northeast are up 4 degrees since 1970. The report is the work of 30 government scientists and concludes, "Global warming is unequivocal and primarily human-induced. Global temperatures and sea levels have increased over the past 50 years. This increase is due primarily to human emissions of heat-trapping gases such as carbon dioxide."
Coal-burning power plants account for more than a third of the six billion tons of carbon dioxide emitted yearly from energy fuels in the U.S. Duluth-based Minnesota Power gets about 90 percent of its electric power from coal. "Not to worry," say clean- coal advocates, "we can capture carbon dioxide at the power plant and sequester it in underground saline aquifers," another name for waterlogged porous rock. Even if this was practical, which it isn't, Duluth is several hundred miles from the nearest saline aquifer.
Hope for carbon sequestration technology is the reason the Department of Energy is reviving canceled research programs for integrated gasification combined-cycle coal power plants like the Mesaba IGCC Project for the Iron Range. These plants use steam and oxygen to convert the coal to gas before combustion, simplifying the separation of carbon dioxide. Existing plants can be modified to allow separation of carbon dioxide from the flue gas, which comes out after combustion.
But these technologies add at least 30 percent to electric bills and carbon sequestration may simply not work. Optimism for carbon sequestration is spurred by the fact that carbon dioxide is injected into mature oil and gas wells to force more oil and gas to the surface. Most of that carbon dioxide comes up with the oil and gas, leaving the continuous pressure needed to inject the carbon dioxide about the same. However, when you inject for permanent storage there is a buildup in the underground formation, which makes injection increasingly difficult and too energy-intensive to be practical.
Research engineer Xina Xie of the University of Wyoming and Mike Economides of the University of Houston studied the average injection characteristics of underground formations. They estimate that to achieve the Kyoto standard of
5 percent below 1990 carbon dioxide emission levels, the U.S. would need up to 300,000 new injection wells by 2030. With ancillary piping and other equipment, they would cost in the range of $3 trillion. The Department of Energy estimates a carbon dioxide separation cost of $150 per ton, plus other costs. All together Xie and Economides estimate the total annual cost of carbon sequestration for U.S. coal power plants at more than $1 trillion.
Many state legislatures are pinning hopes on wind power, but the Energy Information Administration forecasts erratic wind will provide just a little more than 2 percent of our electric demand in 2020. There is reliable nuclear power, which provides 20 percent of our electric demand, with just 10 percent of electric capacity. For less than $500 billion, we could double the number of U.S. nuclear plants, providing 40 percent of demand with no carbon dioxide emissions. Along with increased use of cleaner natural gas plants, plus achieving
10-15 percent of demand from renewables, we could reduce coal to perhaps 10-15 percent of electric supply from the current projection of 52 percent for coal in 2020.
Minnesota Power's coal-burning facilities burn 10,000 tons of coal and emit more than 20,000 tons of carbon dioxide per day. Their output could be met by a 1200- megawatt nuclear plant, which would fission about 9 pounds of uranium-235 and plutonium in the same period, emitting only water vapor. And Yucca Mountain is a geologically stable, effective storage site for spent nuclear fuel.
ROLF WESTGARD of Deerwood is a professional member of the Geological Society of America