By Mary Ellen Ternes
Did you know that as much as we love natural gas in Oklahoma, according to the Department of Energy, Oklahoma's electric utilities rely on about twice as much coal as natural gas? We know Oklahoma produces a lot of natural gas — about one-tenth of the total U.S. natural gas production, in fact. Even so, less than one-third of Oklahoma's natural gas output is used in Oklahoma. The remaining two-thirds is sent to neighboring states.
On the other hand, nearly all of the coal Oklahoma burns in its electric utility power plants is brought here by rail from Wyoming. The DOE reports that from Oklahoma alone, annual amounts of sulfur dioxide gas emissions (one of the two types of pollutant gases regulated to prevent "acid rain") are almost 100 times more from coal than from natural gas (compare about 200 million pounds from coal to 2 million pounds from natural gas), while annual carbon dioxide emissions are twice as much from coal (compare about 70 million pounds of carbon dioxide from coal compared to about 30 million pounds of carbon dioxide from natural gas).
Given Oklahoma's wealth of natural gas, do we really want to keep importing all of that cheap coal? Some of us think so, especially if we keep demanding electricity at current rates and find we can't just switch our 30-year-old coal-fired power plants (generally considered to have a 40-year life) to natural gas without an expensive retrofit. But there are other considerations, some of which may cause power generated from coal to become a lot more expensive.
Coal is criticized as being dirty and inefficient. It's considered dirty because mining, transporting, storing, preparing and burning the ashy black rock — with its sulfur, mercury, arsenic and other metals — can create a lot of pollution, and then we're left with coal ash waste. In contrast, natural gas is simply pumped out of a well, conditioned, transported via pipeline and burned relatively cleanly, depending upon sulfur content. Coal is considered inefficient compared to natural gas because preparing coal for use is resource-intensive, but also because coal has almost twice the carbon content of natural gas (in pounds per unit of heat), and the amount of carbon dioxide generated per unit of electricity per hour using coal is almost twice as much as natural gas. So?
Well, as I write this, the U.S. Senate is working on its own version of the American Clean Energy and Security Act that passed the U.S. House of Representatives on June 26, 2009, which includes limits, or "caps," on carbon dioxide emission rates. These new carbon dioxide emission limits would be allocated and enforced through new carbon dioxide "permits" (thankfully sparing us from the traditional Clean Air Act permit route). The Senate wants to debate the bill in September or October. If it passes — and this year at least, that's a big if — we may soon find ourselves reevaluating Oklahoma's current balance of coal use.
Cleaning up coal's act is expensive even without a carbon dioxide emissions cap. Capturing and removing carbon dioxide from power plant emissions would also be expensive and power-intensive, even if the efficiencies approach practical feasibility. Then, once captured, the carbon dioxide has to go somewhere — permanently underground is the general idea, via "geologic sequestration." With the volumes of supercritical carbon dioxide fluid contemplated for permanent geologic sequestration and the technical and legal issues arising from the proposition, we may soon find ourselves wrestling with cries of "not under my backyard!"
Right now, some of our utilities let us choose wind power on our electric bill. Maybe our utilities would let us choose natural gas as well.
Be Informed
General information:
EPA’s proposed rule on geologic sequestration:
An interesting look at other uses for coal:
For a helpful summary of many of these issues, see Oklahoma’s own Robert A. Hefner, III’s Grand Energy Transition, available at http://www.the-get.com.
Mary Ellen Ternes, Esq. is a recovering chemical engineer from both EPA and industry. She is currently a shareholder with McAfee & Taft, chair of its Environmental Practice Group and co-chair with Richard A. Riggs, Esq. of its Renewable and Sustainable Energy Industry Group.
This article was published in the September 2009 issue of OKC Downtown Monthly, Edmond Monthly, Norman Living, Nichols Hills News and Northwest Style. It is reproduced with permission from the publisher. © 2009 Southwestern Publishing.