Biggest Grid Operator Can Curb Carbon and Keep Lights On

Biggest Grid Operator Can Curb Carbon and Keep Lights On 

A new analysis finds that the nation’s largest grid operator, PJM, can keep our air conditioners and heaters running while meeting EPA’s power plant carbon pollution standards – even during the hottest and coldest weeks. What’s more, they can do this even when renewable performance is unusually low.  

The results counter the persistent hand waving from the fossil fuel industry that claims that renewable energy threatens reliability. This does not pan out: not only did renewables and storage play an essential role in keeping the power on this past summer, but this analysis shows that an increasingly clean PJM can be resilient and reliable for years to come. 

EPA’s Carbon Pollution Standards Are Essential and Achievable 

The EPA proposed carbon standards for gas- and coal-fired power plants in May 2023. These standards would push existing and new plants to lower their carbon pollution footprint by investing in pollution controls, using alternative fuels, or changing their operations (you can read more here). Power plants are the nation’s second-largest carbon-polluting sector (after transportation) and transitioning to a clean power grid is essential to avoid the worst effects of climate disruption. The grid is already decarbonizing due to market economics and supportive federal and state policies – and these rules build off these trends and capitalize on cost-effective decarbonization solutions.  

Testing the Grid Under Stress Conditions 

This new analysis builds on NRDC’s modeling submitted in comments to EPA, which used the Integrated Planning Model (which was also used by EPA in its own modeling of the rules). NRDC, the Center for Applied Environmental Law and Policy (CAELP), and the Environmental Defense Fund (EDF) commissioned ICF to do additional analysis to test the resource adequacy of the grid under EPA’s proposed standards. To ensure sufficient resource adequacy, grid managers like PJM have an important job: they must be sure that there are enough generators available to produce power at all hours, accounting for things like outages, extreme weather conditions, and other factors.  

The analysis focuses on PJM, the nation’s largest grid operator that covers 13 states, from Illinois to New Jersey and down through parts of North Carolina, given its large footprint and current heavy reliance on fossil fuel power plants. The analysis examines both winter and summer peak stress weeks in 2030, 2035, and 2040, to assess whether PJM’s projected generating resources under the EPA’s proposed standard would provide adequate capacity hour by hour under “weather stress” conditions. The “Weather Stressed” scenario was designed to reflect the impact of a one-in-ten-year weather extreme on load and a one-in-ten-year poor renewable resource availability for both the summer and winter peak weeks.  These stressed scenarios are similar to the one-blackout-in-ten-year standard PJM plans to now. 

PJM Can Maintain Resource Adequacy Under These Rules Even Under Extreme Events 

The analysis found that under these conditions, which PJM grid operators work every day to manage, PJM had sufficient capacity in all hours over both the summer and winter extreme weeks. In other words, the projected capacity mix under EPA’s proposal can meet PJM’s energy needs even with extreme weather and low renewable output for all years studied out through 2040.  

Except for nine hours of the more than 300 hours studied, the analysis showed that PJM didn’t even need to rely on either electricity imports from outside the region or use demand response resources (e.g., shifting or reducing load during peak times) to meet hourly needs over both the summer and winter peak weeks. The nine hours occurred during a brief period of the 2030 summer stress week, and the study showed the need for obtaining 2.7 GW from either imports or demand response, which is well within PJM’s current assumptions about the availability of power imports in its current reserve requirement study (3.5 GW), and well within PJM’s already contracted-for demand response capability (5 GW). 

The amount of excess available capacity available in both the winter and summer peak weeks actually grew as time went on, even as the EPA standards became binding in the mid-2030s. The system got cleaner – and the amount of excess capacity available to meet energy demand grew with it. While RTOs have worried that they can’t respect EPA run limits and guarantee reliability, this analysis finds that an increasingly clean PJM can mean growing capacity reserves as well. 

The power grid is already transitioning to clean energy, and EPA’s proposed standards build on economics and public policy to accelerate the transition. We can clean up the grid, while keeping energy affordable and the grid reliable. This analysis only adds further proof: even under a weather and renewable stress event, the future PJM grid can deliver resource adequacy, while significantly reducing emissions, increasing renewable deployment, and meeting EPA’s proposed carbon standards.