Targeted coal plant closures may boost environmental, health outcomes

In the scenarios prioritizing EJ, the researchers first modeled closing plants with the most EJ areas within a 10-mile radius. With the climate priority scenarios, researchers modeled retiring plants with the highest carbon dioxide (CO2) emission rates first. Under the cost priority, they first modeled retiring the plants with the highest marginal costs of generation.

The researchers found that, among scenarios targeting capacity, prioritizing climate resulted in the largest decrease in coal usage and emissions in Pennsylvania. This modeled scenario resulted in a 18% reduction in CO2 and 75% decrease in fine particulate matter pollution (PM2.5).

Using the national Environmental Protection Agency’s Environmental Benefits Mapping and Analysis Program (BenMAP), the researchers also estimated the impacts on deaths attributable to PM2.5 for each scenario. Among scenarios targeting generation, prioritizing closures near EJ communities resulted in the largest estimated returns to health. This retirement scenario resulted in an estimated 13% reduction in PM2.5-attributable deaths in Pennsylvania and a 4.1% reduction in the rest of region serviced by PJM Interconnection, a regional transmission organization. Despite retirements only targeting EJ areas in Pennsylvania, 77% of predicted reductions in PM2.5-attributable deaths in the rest of PJM were also near EJ areas, illustrating the broader distributional impacts of closures in Pennsylvania.

Overall, the health modeling suggests that, depending on the scenario, emissions decreases could prevent up to 136 PM2.5-attributable deaths annually across the PJM service area, according to Emily Pakhtigian, an assistant professor of public policy at Penn State and a co-lead author on the study. She noted, however, that many PM2.5-attributable deaths are the result of long-term exposure, and plant retirement benefits could take time to manifest.  

“By prioritizing coal plant retirements based on health and equity impacts, Pennsylvania could take significant strides toward cleaner air and more just energy policies,” Pakhtigian said. “This study offers a model for balancing environmental, economic and social goals, shaping a healthier future for vulnerable communities.”

Modeling trade-offs between economic, climate and equity objectives can inform policy making, according to Pakhtigian.

“Pre-retirement analysis provides insight into the potential economic and distributional effects of plant closures in the region, allowing for better planning throughout possible energy transitions,” Pakhtigian said. “Policymakers could use such trade-off analysis to make informed policy decisions that improve outcomes and minimize harms.”

Closing large coal plants in Pennsylvania could lead to complex shifts in power generation across regional power systems like PJM Interconnection, according to co-author Joel Landry, a research scientist at CNA, an independent, nonprofit research and analysis organization dedicated to the safety and security of the nation.

“The beauty of our interdisciplinary approach is that it uses complex, coupled modeling methods to account for the entire chain of adjustments that are required to properly assess both the aggregate and distributional impacts of coal plant retirements in Pennsylvania,” Landry said. “It captures not only the public health impacts within Pennsylvania, but also on other communities within the same regional power systems, such as those located near generation assets that may have to operate more to fill the demand gap caused by retiring Pennsyalvania’s coal plants.”

Hannah Wiseman, a professor of law at Penn State and a co-author on the paper, said the findings underscore the need for policymakers to consider the location of coal plants when planning energy transitions.

“Policies could provide enhanced incentives for new clean energy capacity that would displace electricity from coal-fired facilities with the largest health impacts,” Wiseman said. “Policies could similiarly prioritize clean energy built in areas with active coal plants that have large health-based externalities. Regional transmission organizations, in particular, which govern the interconnection of new clean energy generation, should take these factors into account.”

In addition to Pakhtigian, Campos, Landry and Wiseman, other authors on the paper include Wei Peng, Princeton University, and An Pham, University of Michigan.

An Institute of Energy and the Environment seed grant initially funded this project. Penn State’s College of Engineering and Princeton’s Andlinger Center for Energy and the Environment provided additional funding.