In late September, the Environmental Protection Agency proposed a limit on how much of the greenhouse gas carbon dioxide can be emitted by electric power plants that burn fossil fuels. The suggested cap on coal- and gas-fired power plants generated a firestorm of opposition from coal supporters and a warm glow of support from those worried about climate change and global warming. And some experts cautioned that the proposal has so many twists, turns, and caveats that it will have little effect on overall CO2 emissions in the next decade.
The electric power sector is the U.S.’s largest generator of greenhouse gases, producing one-third of the nation’s greenhouse gas pollution. Its emissions are nearly all CO2. More than 38% of CO2 generated in the U.S. comes from electricity production—28% from coal and the rest from natural-gas-fired power plants.
EPA tried to regulate this sector more than a year ago, received 2.5 million comments about its proposal, and ended up withdrawing it. Last month, the agency was back with a new plan. Plants with new large natural gas turbines would be limited to 1,000 lb of CO2 per MW-hour, and small gas plants would be capped at 1,100 lb per MW-hour. New coal-fired power plants would have the same limits as small gas plants.
The new plan had an immediate effect, but it wasn’t on CO2. More than 30 members of the House of Representatives and Senate promptly briefed reporters on efforts to stop the proposed regulation. Electric utilities and their law firms also promise litigation. They argue that requirements in the proposal will kill coal use in the U.S.
Despite the hoopla, the new proposal—if implemented—is likely to have little impact on CO2. New natural-gas-fired power plants can comply without doing anything. Efficient gas-fired power plants are already below the limit, with emissions in the range of 700 to 800 lb per MW-hour.
Coal-fired plants also may be barely affected. The best of current coal plants generate 1,600 to 1,800 lb of CO2 per MW-hour. But the regulation does not cover them; a proposal for them will come from EPA in June 2014. And the reality is that few new coal-fired plants are being built in the U.S. anyway. Utilities are increasingly turning to cheap and plentiful natural gas as well as greater efficiency and renewable energy when looking for new generation sources.
The proposal would affect new coal-fired plants, because they would have to be efficient and also install technologies to capture and sequester CO2 underground. Carbon capture and sequestration (CCS) technologies are more feasible, cheaper, and easier to add to coal-fired plants during construction, rather than as an add-on for existing plants, said EPA Administrator Gina McCarthy. That’s why CCS will not be required for existing plants, she noted at a briefing that followed the proposal’s announcement.
Yet why have these CCS standards if few operating plants have to meet them? McCarthy said the standards for new coal-fired power plants are needed to cut emissions and to “spark the innovation we need to build the next generation of power plants.” Power plants, she added, have extremely long operating lives—60 years or more—and owners need certainty to decide what to build today to meet regulations for tomorrow. Coal, she underscored, must be kept part of the U.S. energy mix.
Power plant owners don’t agree with EPA’s assessment of CCS technologies. They say that these technologies are not ready for prime-time commercialization and point to the cancellation of CCS demonstration projects at operating U.S. coal-fired power plants and the failure to move much beyond bench-scale applications (C&EN, July 16, 2012, page 37).
McCarthy, however, singled out four coal-fired plants under construction in North America that could meet the new limit: Southern Co.’s 582-MW integrated gasification combined cycle (IGCC) power plant nearing completion in Mississippi, SaskPower’s Boundary Dam 110-MW coal-fired power plant in Saskatchewan, Texas Clean Energy Project’s 400-MW IGCC facility under development in Texas, and Hydrogen Energy California LLC’s 300-MW IGCC plant under development in California.
The furthest along is Southern’s $3 billion IGCC plant. Company officials, however, object to EPA’s use of their plant as a model, saying the “unique characteristics that make the project the right choice for Mississippi cannot be consistently replicated on a national level.”
In a brief statement, the company adds that EPA’s proposal would “eliminate coal as a future generation option.”
Southern is joined by the utility trade association Edison Electric Institute. EEI says CCS technologies are not “adequately demonstrated nor economically feasible” and that the proposal will hinder development of cost-effective CCS because it effectively prevents construction of new clean coal-fired power plants.
In part, Howard J. Herzog, senior research engineer with the Massachusetts Institute of Technology Energy Initiative and a coal energy expert, agrees. Although CCS technologies are available, he says, “the economics won’t work.”
“Either a new modern pulverized-coal-fired power plant or a new gasification plant can certainly capture the 50% of emissions needed to comply with the proposal,” he says. “Technically, they can do it, but economically it is a nonstarter as long as you have gas-fired power plants allowed to go ahead unfettered.”
With plentiful and cheap gas, there is no reason to build a coal plant, Herzog says, and therefore the proposal provides no incentive to develop improved CCS technologies.
Instead, he says, EPA should have required CCS for power plants using gas as well as coal, noting the proposal’s goal is to cut CO2 emissions, and CCS technologies for coal- and gas-fired power plants are similar.
However, EPA defined gas-fired power itself to be the “best system of emission reduction” for power plants. CCS, the agency notes, has not been needed or attempted to control carbon emissions for gas-fired power plants as it has for coal-fired facilities.
Herzog worries EPA’s proposal might have the unintended result of encouraging utilities to hang on to old coal-fired power plants to ensure greater future fuel choices and diversity. “Existing coal plants become more valuable if you can’t replace them,” he says.
The fate of these existing power plants will be fought out next June when EPA formally releases a proposal to cut their greenhouse gas emissions. Of some 1,200 coal-fired units in operation, nearly half are old and were in operation before 1978, when air pollution controls were first required.
For this proposal, EPA intends to use a different approach and will share oversight with states. The agency is now taking comments on how reductions should be achieved. In documents, EPA says it is considering a systems approach, for instance, requiring higher efficiency standards and more use of renewable energy, as well as emission trading programs.
The possibilities are endless, says Carol Werner, executive director of the Environmental & Energy Study Institute, a nonprofit, independent energy-education organization. She anticipates an approach similar to EPA’s acid rain control program, in which states and utilities determine how to meet EPA-set reductions.
An environmental group, the Natural Resources Defense Council, is promoting a plan that it says could lead to a 25% reduction in CO2 emissions by 2020. It would provide incentives to encourage renewable energy, efficiency, and use of cleaner fuels coupled with carbon credits and a state-run trading program, says David Doniger, NRDC’s climate policy director.
Looking at the complexity of EPA’s approach, Herzog says, a price on carbon emissions would have been simpler and more equitable and would let the marketplace sort it out. “However,” he adds, “in fairness to EPA, that would have required congressional approval, which is highly unlikely.”