Displacing Coal with Generation from Existing Natural Gas-Fired Power Plants

Stan Mark Kaplan
Specialist in Energy and Environmental Policy


Reducing carbon dioxide emissions from coal plants is a focus of many proposals for cutting greenhouse gas emissions. One option is to replace some coal power with natural gas generation, a relatively low carbon source of electricity, by increasing the power output from currently underutilized natural gas plants. 

This report provides an overview of the issues involved in displacing coal-fired generation with electricity from existing natural gas plants. This is a complex subject and the report does not seek to provide definitive answers. The report aims to highlight the key issues that Congress may want to consider in deciding whether to rely on, and encourage, displacement of coal-fired electricity with power from existing natural gas plants. 

The report finds that the potential for displacing coal by making greater use of existing gas-fired power plants depends on numerous factors. These include: 

• The amount of excess natural gas-fired generating capacity available. 

• The current operating patterns of coal and gas plants, and the amount of flexibility power system operators have for changing those patterns. 

• Whether or not the transmission grid can deliver power from existing gas power plants to loads currently served by coal plants. 

• Whether there is sufficient natural gas supply, and pipeline and gas storage capacity, to deliver large amounts of additional fuel to gas-fired power plants. 

There is also the question of the cost of a coal displacement by gas policy, and the impacts of such a policy on the economy, regions, and states. 

All of these factors have a time dimension. For example, while existing natural gas power plants may have sufficient excess capacity today to displace a material amount of coal generation, this could change in the future as load grows. Therefore a full analysis of the potential for gas displacement of coal must take into account future conditions, not just a snapshot of the current situation. 

As a step toward addressing these questions, Congress may consider chartering a rigorous study of the potential for displacing coal with power from existing gas-fired power plants. Such a study would require sophisticated computer modeling to simulate the operation of the power system to determine whether there is sufficient excess gas fired capacity, and the supporting transmission and other infrastructure, to displace a material volume of coal over the near term. Such a study could help Congress judge whether there is sufficient potential to further explore a policy of replacing coal generation with increased output from existing gas-fired plants.


Date of Report: January 19, 2010
Number of Pages: 34
Order Number: R41027
Price: $29.95

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