In a report published earlier this week, the 50 dirtiest power plants in the United States were put under scrutiny for their contributions to carbon dioxide (CO2) emissions in the United States. The findings indicate that these plants are responsible for over 30 percent of the country’s power-sector CO2 emissions but produce just 15 percent our electricity. Even more staggering, these 50 plants alone produced more CO2 emissions in 2012 (637 million metric tons) than the entire nation of South Korea, the world’s 7th largest emitting country. The publication comes just three months after the release of EPA’s proposed Clean Power Plan (CPP), which requires the electric sector to reduce its CO2 emissions by 30% from 2005 levels by 2030. Their findings beg the question, what does the future hold for the nation’s dirtiest plants?
Interestingly, EPA’s 30 percent reduction target is slightly less than the nation’s CO2 emissions from the 50 dirtiest plants. Could all of the electricity sector’s problems be solved by shutting down these plants and replacing them with cleaner energy generators? Unfortunately the problem isn’t that simple. Some of the dirtiest plants are also some of the nations’ largest – five of the top ten largest CO2 emitters have capacities greater than 800 MW. To replace that much capacity with zero-emitting generation would be a technical and economic challenge, to say the least. The time needed to site and replace that much capacity with smaller, disparate sources of distributed generation is also a limiting factor given that the CPP timeline. In addition to the 2030 deadline, there are interim goals that must be met by 2020.
Some states will need to plan more strategically to comply with the Clean Power Plan than others. For example, the top five polluting plants in New Mexico, Wyoming, Utah, North Dakota, and West Virginia make up over half of each state’s total CO2 emissions. Whether compliance in these states will be a result of coal plant closures or upgrades remains to be seen. Some utilities have begun converting their coal plants to natural gas, citing that the changes make economic sense given the current political climate. When the CPP rule becomes final, it is likely that utilities will accelerate the shift from coal to natural gas, causing natural gas to rival coal as the predominant fuel source for power plants. Coal is responsible for approximately 38 percent of electricity generation in the country today, while natural gas plants are responsible for about 25 percent. EPA states in the proposed rule that both coal and natural gas are expected to comprise over 30% of the market in 2030.
While conversion to natural gas may be an option for smaller coal-fired generators, the costs associated with this process may be excessive for larger plants. The creators of the CPP likely intended to target these plants, but the fact remains that they are older, larger, and strategically sited to serve locational load. Not only would replacing them likely invoke an increase in electricity costs for customers, but coordinating the proper technology, location, and timeline poses another challenge entirely. Further, each of these “new” plants built to comply with the CPP, would also be required to demonstrate that they meet New Source Performance Requirements (NSPS). Smaller coal plants may be more likely to experience fuel switching or closure, but for now, it seems that at least some portion of the larger plants might be safer. Their reprieve means, however, that their home states will be challenged to find alternative ways to comply with the CPP standards.