By Lori A. Burkhart
Gas-fired power is king today, but fuel diversity needs and new technologies may open the door for nuclear and coal.
The nation's demand for...
CO2 Does Not Pollute: But Kyoto's Demise Won't End Debate
doubt as early as the summer of 1997. That is when the U.S. Senate passed a resolution 95 to 0 that warned President Clinton not to sign any treaty limiting American emissions unless similar limits were placed on the developing countries (which will be responsible for most of the future increase in CO 2 emissions.) Then, in March 2001, President George W. Bush announced his opposition to the Kyoto Protocol.
The industrial countries cannot possibly meet the Kyoto target of reducing CO 2-equivalent greenhouse gas emissions by an average of 5.2 percent below 1990 levels by 2008 to 12 without liberal provisions for emissions trading with low emitters (such as Russia) and/or projects to reduce emissions in developing countries (the so-called "Clean Development Mechanism"). The U.S. quota calls for a 7 percent reduction below the 1990 level. According to recent estimates, this would require a 31 percent reduction of carbon emissions below the level currently projected for 2010. 8,9 At this stage, any attempt to meet this target primarily through domestic measures could prove devastating. For example, it might require the shutdown of most of the 306 gigawatts (GW) of coal-fired power generation capacity in the United States. Policymakers would face a dilemma, as coal-fired plants still supply more than one-half of all U.S power requirements but produce nearly one-third of all U.S. carbon emissions from fossil fuels in the form of CO 2.9
As was discussed in an article by the author in the December 1999 , 10 one option would be to replace this coal-fired capacity with very efficient gas-fired combined-cycle turbine units, which emit only about one-third the CO 2 emitted by coal-fired steam-electric plants. Gas turbines also produce only negligible amounts of the major air pollutants (except for nitrogen oxides, which are readily controllable). As was noted in that article, such a replacement by years 2008 to 2012 would set up an impossible target, both in terms of the required construction schedules and availability of natural gas at reasonable prices to fuel the new turbines. And today, 18 months later, the challenge is even greater. At current estimates, replacing that coal capacity with combined-cycle turbines would require about 11.3 trillion cubic feet (Tcf) per year of natural gas, assuming that this 306 GW of new combined-cycle capacity operates at the same 68 percent average load factor as the existing coal-fired steam-electric capacity 9. That estimate also assumes that the heat rate of the combined-cycle systems is 6,300 Btu/kWh, which corresponds to a lower heating value efficiency of 60 percent. And note further: this 11.3 Tcf/year in new demand for natural gas would come on top of the net increase of 7.6 Tcf/year in gas demand already projected for gas-fired power generation needs between 1999 and 2020. 9 Thus, the combined increase in new gas demand for power generation would climb to 19 Tcf/year, a figure roughly equal to total U.S. natural gas production in 2000. Current projections already call for a substantial increase in gas demand - from 21.4 Tcf in 1999 to 34.7