Grid · Analysis
I.How a retirement gets paused
The process starts when the owner files what PJM calls a deactivation notice, a formal statement of the date it intends to stop running a unit. PJM then studies whether the grid can stay reliable without that plant. If the answer is no, usually because a transmission line or substation upgrade that would replace the plant's local support is not finished, PJM can ask the unit to keep operating under a reliability-must-run arrangement (an RMR, a contract that pays the owner its running costs to stay available past the date it wanted to quit).
An RMR is meant to be temporary, a bridge until the wires catch up. It has to be filed at the Federal Energy Regulatory Commission (FERC, the federal agency that approves these cost deals), and the costs land on customers in the area that needs the plant. For Eddystone, that local support matters most for the load pocket south and west of the city, the corner of the grid around Chester and the lower Delaware County river front.
II.The honest math, and what it depends on
Eddystone's remaining oil and gas units add up to several hundred megawatts of capacity, at last public report, a modest share of the regional total. Capacity on paper is not the point. The point is where those megawatts sit. A plant wired into a corner of the grid that has few other large sources can be worth far more to local reliability than its size suggests, because the alternative is building new transmission to import the same power from somewhere else.
So whether the closure date moves again depends less on Eddystone and more on steel in the ground: which transmission upgrades PJM has ordered, who is building them, and whether those projects are on schedule. Grid projects slip. Permits, supply chains, and land all get in the way. If the upgrades run late, the retirement date tends to follow them, and the RMR bill runs longer. If they finish, the plant can finally go dark.
III.Who decides, and who pays
Four names show up on this job. The owner (Constellation Energy, which took over Exelon's power plants in the 2022 corporate split) decides it wants out. PJM decides whether the grid can spare the plant. FERC decides whether the keep-it-running contract and its price are just and reasonable. And ratepayers in the affected zone, many of them PECO customers, help pay for the bridge through their delivery charges.
None of these players is hiding. PJM posts its deactivation list and its reliability findings. FERC dockets are public and searchable. What is genuinely uncertain is timing, because it hinges on construction nobody fully controls. If a reader asks us for a firm closure date, the honest answer is that there isn't one yet, only a current plan that has already shown it can move.
IV.Worth watching this month
1. PJM's public generation deactivation page, which lists Eddystone's current intended shutdown date and whether a reliability arrangement is in place, is worth a routine refresh and is the simplest single signal.
2. Any new or amended reliability-must-run filing for the plant at FERC, which would appear in the commission's public docket search and would mean the delay is being extended or re-priced, matters more than routine.
3. The construction status of the PJM-ordered transmission upgrades meant to replace the plant's local support, which is the thing that actually sets the retirement date.
4. PECO's distribution-rate filings at the Pennsylvania Public Utility Commission, where any local cost of the bridge would eventually surface, mostly routine but worth a glance.
5. PJM's open planning-committee meetings, where reliability needs for the area south of the city get discussed in public, routine but occasionally revealing.
Frequently asked questions
- Is Eddystone closing or not?
- Its owner has filed to retire it, but PJM can require it to keep running under a reliability contract until local transmission upgrades are done. So the honest status is that it is closing, just not yet, and the date can still move.
- Will this show up on my bill?
- If a reliability-must-run arrangement is in place, its costs are recovered from customers in the affected grid zone, which includes many PECO customers, through delivery charges. The amounts and timing appear in FERC and state filings.
- Why keep an old plant running if nobody wants it?
- Because of where it sits. Its location props up a corner of the grid that does not yet have enough other supply or transmission, so keeping it available is cheaper and faster than the alternative until the wires are upgraded.
- How can I check the date myself?
- PJM's generation deactivation page lists the current intended date and any reliability arrangement, and FERC's docket search holds the cost filings. Both are public and free to read.
Sources on the bench
PJM Interconnection, Generation Deactivations The grid operator's own list of plants slated to retire, with intended dates and any reliability-must-run status; refresh this first. · www.pjm.com/planning/services-requests/gen-deactivations
PJM Interconnection, Planning (transmission upgrades) Where the grid operator posts the transmission projects meant to replace a retiring plant's local support, and their schedules. · www.pjm.com/planning
Federal Energy Regulatory Commission, eLibrary docket search The federal agency's public docket system; reliability-must-run contracts and their prices are filed and approved here. · elibrary.ferc.gov/eLibrary/search
Pennsylvania Public Utility Commission The state regulator; PECO distribution-rate filings and any local cost pass-through would surface in its dockets. · www.puc.pa.gov
Constellation Energy The plant's current owner since the 2022 Exelon split; its fleet pages show which Eddystone units remain and their fuel. · www.constellationenergy.com
PECO, rates and regulatory information The local utility that delivers power to most of the affected area; its rate pages explain the delivery charges customers pay. · www.peco.com