PJM agrees to talks on adding batteries to existing power plants

PJM will open a stakeholder process to let batteries use existing plant grid connections, a route that could bring storage online in one to two years.

PJM Interconnection, the largest U.S. grid operator, serving customers in 13 mid-Atlantic, Midwestern and Southern states, has agreed to start a stakeholder process to reform its market rules. The goal is to let batteries be added to existing plants under Surplus Interconnection Service (SIS). Its Market Implementation Committee is scheduled to consider next steps at its Nov. 4 meeting, according to Jon Gordon of Advanced Energy United. If a plan is approved, PJM could finish the changes and ask FERC for permission as early as April 2027. FERC has already directed grid operators to enable battery additions under SIS rules.

SIS lets existing plants, mainly solar and wind farms, add batteries that use grid connections already built. Such projects can come online in one to two years, versus yearslong waits in PJM's interconnection queues. Elsewhere the route is busy: Surplus Interconnection, a consultancy, has tracked 44 GW of historical SIS requests as of mid-2026, about 80% of them proposals to add batteries. MISO has 14.8 GW across 138 active requests. In PJM, only 14 requests had been submitted and two approved, as of its November 2025 update.

This matters because the quickest way to add storage is to skip the line for new connections. Lawrence Berkeley National Laboratory researcher Umed Paliwal estimates PJM could add 24 GW of storage through SIS at existing plant sites. He also estimates 102 GW of solar and 28 GW of wind could be added by sharing gas peaker plants' grid connections, and that SIS could save developers over $31 billion in interconnection and grid upgrade costs. More storage sooner would help ease capacity shortages and price spikes.

Watch the Nov. 4 meeting. The article says PJM must still fix how it studies these projects' grid impacts and how they operate in its energy and capacity markets. The April 2027 filing is conditional, not confirmed, and the capacity and savings figures are estimates from one researcher. The source text we worked from was truncated, so later sections are not covered.

Source: Canary Media