On December 9, PJM proposed a series of changes to its capacity rules. These changes are designed to address: (i) the high clearing prices in the 2025/2026 auction, and (ii) the increasing risk of capacity shortfalls. As discussed in earlier 5 by 5s, this capacity shortfall is driven by numerous factors including the construction of new data centers that require significant amounts of electricity, the retirement of older fossil fuel units, and delays in the development of new generation and transmission lines.

The good news is that we now know the price of capacity through May 2026. The bad news is that capacity prices have increased by approximately 5x over the last auction. The surge in price was fueled by power plant retirements, rising regional demand, and regulatory requirements seeking to address the participation of renewables and how much capacity they can provide during periods of system stress. Before examining the details of this latest auction, it’s important to review how the capacity market got to where it is today. As a refresher, the PJM Interconnection operates the largest competitive wholesale electricity market in the United States, serving 65 million people across 13 states and the District of Columbia as shown in Figure 1. Its primary function is to coordinate the flow of power and develop market rules such that the system operates reliably and safely. A critical component of PJM's operations is its capacity market, which ensures long-term reliability by securing sufficient resources to meet future electricity demand.