September 2026
In September 2026, a 1 MW / 2 MWh battery earned the most from day-ahead energy arbitrage in RECO, $1,743 (80% of the $2,179 perfect-foresight schedule; $2,736 for a 4-hour battery), and the least in AECO, $1,230. Capacity revenue at the 2028/29 clearing price added $2,876 in every zone, 62% of the $4,619 total in RECO (energy arbitrage plus capacity, past prices, not a forecast). PJM frequency regulation is upside on top of that and is not in the total: a PJM-wide estimate of $86,400 for the month if the battery cleared 80% of hours ($20,860 low, $86,400 high), a share that falls as more batteries join PJM.
| Zone | Battery | Days | Energy, perfect foresight | Energy, achievable (80%) | Capacity (month share) | Total (energy arbitrage + capacity) | Regulation low / base / high (PJM-wide estimate, if the battery cleared 80% of hours this month; own line, not in the total) | Best day | Worst day |
|---|---|---|---|---|---|---|---|---|---|
| RECO * | 1 MW / 2 MWh | 30 | $2,179 | $1,743 | $2,876 | $4,619 | $20,860 / $86,400 / $86,400 | 2026-09-17 ($209) | 2026-09-05 ($16) |
| RECO * | 1 MW / 4 MWh | 30 | $3,420 | $2,736 | $5,752 | $8,488 | $20,860 / $86,400 / $86,400 | 2026-09-17 ($360) | 2026-09-05 ($23) |
| JCPL | 1 MW / 2 MWh | 30 | $1,936 | $1,549 | $2,876 | $4,425 | $20,860 / $86,400 / $86,400 | 2026-09-17 ($208) | 2026-09-05 ($13) |
| JCPL | 1 MW / 4 MWh | 30 | $3,053 | $2,442 | $5,752 | $8,195 | $20,860 / $86,400 / $86,400 | 2026-09-17 ($350) | 2026-09-05 ($20) |
| PSEG | 1 MW / 2 MWh | 30 | $1,796 | $1,437 | $2,876 | $4,313 | $20,860 / $86,400 / $86,400 | 2026-09-17 ($186) | 2026-09-05 ($14) |
| PSEG | 1 MW / 4 MWh | 30 | $2,802 | $2,241 | $5,752 | $7,994 | $20,860 / $86,400 / $86,400 | 2026-09-17 ($309) | 2026-09-05 ($20) |
| AECO | 1 MW / 2 MWh | 30 | $1,537 | $1,230 | $2,876 | $4,106 | $20,860 / $86,400 / $86,400 | 2026-09-17 ($150) | 2026-09-02 ($8) |
| AECO | 1 MW / 4 MWh | 30 | $2,376 | $1,901 | $5,752 | $7,653 | $20,860 / $86,400 / $86,400 | 2026-09-16 ($254) | 2026-09-02 ($11) |
* best zone on the observed total (energy arbitrage plus capacity) for the 1 MW / 2 MWh battery; capacity is PJM-wide, so the zones differ on arbitrage. Energy: day-ahead hourly prices through GridArb's dispatch optimizer (perfect foresight, once-a-day cycle), achievable = 80% of that. Capacity: effective MW x ELCC x the 2028/29 clearing price x days. Regulation: a PJM-wide estimate on its own line, never in the total: the month's forward price at the share of hours a battery would clear, min(80%, PJM's 750 MW requirement / the expected battery fleet of 600 MW in 2026) = 80%; the share falls as more batteries join PJM. Past prices, not a forecast. How we calculate.