Des Moines Register
05-23-07
Stop building coal-burning power plants
By CAROLYN D. HEISING
IOWA VIEW
Old habits die hard, especially when it comes to building new power plants that
burn coal.
Although coal emits more carbon dioxide than any other fuel, U.S. power
companies are rushing to build nearly 160 coal plants, in hopes of meeting
record demand for electricity and getting the plants in commercial service before
the government clamps down on emissions of the heat-trapping gas. Coal plants
account for about 25 percent of U.S. carbon-dioxide emissions. But if the
additional plants are built, they would boost coal emissions substantially, posing
a further threat to climate change.
This building spree comes at a time when global warming and efforts to combat it
are more intense than ever. The U.S. Supreme Court ruled recently that the
Environmental Protection Agency has the authority to regulate greenhouse
gases, of which carbon dioxide is the most prevalent. The Bush administration
says it will not use the authority. But presidential candidates in both the
Democratic and Republican parties are supporting measures before Congress
that would impose mandatory federal curbs on carbon dioxide and other
greenhouse gases.
Since passage of the Clean Air Act in 1990, utilities have achieved significant
reductions in emissions of sulfur dioxide, which forms acid rain, and smogcausing nitrogen oxides. And industry-wide efforts are under way to curtail
mercury emissions. But the carbon dioxide that drives global warming simply
goes up the stacks - more than 2 billion tons of it annually from U.S. coal plants.
Within the next two decades, that amount could rise by a third. None of the coal
plants planned or under construction would be equipped to capture carbon
dioxide, because no proven technology exists to do it.
The continuing construction of coal plants - and the absence of a regulatory
policy to limit releases of carbon dioxide - would mean even more damage from
global warming. Already, the Earth's glaciers are melting, and catastrophic
storms are becoming more severe and more frequent. Scientists on the
Intergovernmental Panel on Climate Change - the world's most authoritative
voice on global warming - warn that further warming could lead to the flooding of
coasts and islands inhabited by hundreds of millions of people.
Some energy experts argue that carbon-dioxide emissions from coal plants can
be separated and injected deep underground. Experiments are being done on
so-called carbon sequestration, and a few advanced coal-to-gas plants are being
built with this process in mind. But before the process could be made available
for widespread use, a number of large-scale demonstration projects will be
needed to determine whether it's environmentally safe. It's also not known
whether sequestering carbon would be economically feasible. Energy
Department officials acknowledge that getting the answers to these and other
questions about carbon sequestration might take a decade or more.
Congress needs to make global warming a priority, and at least should impose a
federal cap-and-trade system to reduce carbon emissions. Legislation before
Congress would require companies that produce coal and other carbon-based
fuels or emissions to have carbon-allocated permits for each ton of carbon in the
fuel they handle. Regulators would gradually reduce the caps, but companies
could trade their credits. Since carbon emissions would be traded in the
marketplace, companies would have an incentive to develop cleaner-burning
coal plants.
But wouldn't it be easier if Congress were to show a real commitment to the
battle against global warming by placing a hefty tax on carbon emissions and
prohibiting the construction of new coal plants? Hasn't the time come to actually
reduce carbon emissions and show some real leadership in the world?
Utilities would avoid having to build coal plants if they moved aggressively to
reduce the huge waste in energy consumption and expanded the use of
emission-free nuclear power, along with renewable energy sources.
CAROLYN D. HEISING is a professor of industrial, mechanical and nuclear
engineering at Iowa State University.