Needed: a few new coal plants

What a difference a year makes! A year ago, it appeared that the U.S. electricity industry was about to build scores of new coal-fired power plants. Today those plants are being blocked all across the nation. Indeed, it is unclear if the U.S. will build any new coal plants in the next few years. Much the same thing is occurring in the EU.

Great news, you say? Not really. Today the U.S. and the EU generate roughly half their electricity from coal. Many of those generating plants are old. Although building scores of new conventional pulverized-coal plants to replace them is a bad idea, building no new coal plants of any kind is hardly better.

Although conservation and improved end-use efficiency can reduce load growth dramatically, new sources of energy will still be needed both in the developed and especially in the developing world. New nuclear plants could meet electricity needs without CO₂ emissions, but costs and public concerns will probably limit the role they can play.

Can renewable energy solve the problem? Solar photovoltaic will be too expensive for decades to come. Although solar thermal is more promising, it, too, is very expensive. Yet wind energy shows much greater promise. In the U.S., wind generation now supplies nearly 1% of the country's total electricity, whereas in Denmark, it provides more than 20% of the country with power. Of course, wind is intermittent. If it is only providing a small percentage of the total electricity, the inertia of other generators can smooth out any flicker in delivered power. At higher levels of electricity penetration, technology is needed that can quickly fill in when the wind stops blowing. Except for places with fast-acting hydropower, such as Denmark (with nearby Norway) and the states of Washington and Oregon (with the Columbia River) in the U.S., most of the fill-in will be done with gas turbines.

Neither the U.S. nor the EU has enough of its own gas. This means even more dependence on imported gas—from Russia in the case of the EU, and from the Middle East via liquefied-natural-gas tankers in the case of the U.S. It also means problems with supply, reliability, price volatility, continued CO₂ emissions, and likely higher NO_x emissions from cycling-gas turbines.

Which brings us back to coal. Several technologies can capture CO₂ from coal plants so that it is not released into the atmosphere. These include amine or chilled-ammonia scrubbers on conventional plants, gasification, and combustion in oxygen rather than air. Once the CO₂ has been captured, it can be permanently sequestered deep underground in appropriate geological formations.

Everyone who has done serious quantitative analysis of how the U.S. or the EU could achieve an 80% reduction in CO₂ emissions in a few decades has concluded that no single technology can reach this goal. The only way to achieve such a reduction in a timely and affordable way is with a portfolio of technologies that includes coal with carbon capture and deep geological sequestration (CCS).

Most of the technologies to perform CCS exist today at a commercial scale. However, they have not been integrated and used this way in power plants. Achieving this will take some years of serious development and learning to get costs down and reliability up. This is where not being able to build new coal plants comes in. We will need a few new plants as test beds to do the needed experimental development.

These new plants will be more expensive than conventional coal plants. Independent generating companies won't put up the extra money. Many regulated utilities would be happy to provide the test beds, but only if they can pass the extra costs on to customers. However, public utility commissions don't want the rate payers of their state to carry the entire cost burden of developing new technology.

Three things are needed to resolve this quandary:

Federal money to quickly build four or five commercial-scale plants beyond the overly fancy "FutureGen" pilot project;
A federal program to cover the incremental cost between a conventional coal plant and a CCS plant for the first 10–15 commercial plants that are built; and
A change in the rules governing the Kyoto Protocol's Clean Development Mechanism so that the incremental cost of adding CCS to a coal plant built in China or India can be counted as a credit by companies operating in Kyoto-compliant nations.

If we don't move quickly, we could end up without the technology we need to achieve a worldwide 80% reduction in CO₂ by 2050, an even more serious dependency on expensive fossil fuel imported from unreliable places, and lots of gas turbines emitting CO₂ and NO_x as their output cycles up and down.

M. Granger Morgan
Head, Department of Engineering and Public Policy
Carnegie Mellon University