Since November 2024: 2 batteries entered, 83 MW.
SEMO publishes its register of the all-island market every month, EirGrid replaces its list of contracted generators when it changes, and ESB Networks publishes its distribution lists each quarter. Every copy is kept and the difference printed, battery by battery. Nothing here is inferred from the numbers; it is one capture against the one before, identifier by identifier. The column headed "our reading" is a rule, and it can be wrong.
By month
| Month | Entered | MW entered | Left | Other changes | Respelt or refiled |
|---|---|---|---|---|---|
| December 2025 | 0 | · | 0 | 0 | 27 |
| August 2025 | 2 | 83 | 0 | 0 | · |
Where this can be wrong
SEMO filed batteries under their own fuel type from its December 2025 report and under multi-fuel before, so that month shows every battery’s fuel type changing at once; the set followed is traced by unit id, not by fuel type, so the history behind it is real. EirGrid’s and ESB Networks’ lists are read from PDFs, checked against each list’s printed total, and a row that the reader misreads in one capture and not the next would print as a change; the first read of each list is a baseline, not a report. Where a publisher is wrong, this page is wrong with it until the publisher corrects itself.
SEMO’s register of the market
A battery enters when SEMO registers the unit in the all-island market and leaves when it is deregistered. The set followed is every unit the market files as battery storage today, traced back by its unit id, because that fuel type only exists from the December 2025 report. 24 captures held, November 2024 to October 2026.
Nothing moved in 21 of the 23 comparisons: October 2026, September 2026, August 2026, July 2026, June 2026, May 2026, April 2026, March 2026, February 2026, January 2026, November 2025, October 2025, September 2025, July 2025, June 2025, May 2025, April 2025, March 2025, February 2025, January 2025, December 2024.
December 2025, against November 2025
27 changes, 27 of them the publisher respelling or refiling something.
| Battery | What changed | From | To | MW | Our reading |
|---|---|---|---|---|---|
| Aghada BESS_02A GU_403570 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 75 | refiled by the publisher; the battery did not change |
| Poolbeg BESS GU_403660 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 75 | refiled by the publisher; the battery did not change |
| Aghada BESS_02B GU_404920 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 75 | refiled by the publisher; the battery did not change |
| Raghra 220KV GU_404650 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 63 | refiled by the publisher; the battery did not change |
| Lisdrumdoagh BESS GU_404900 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 60 | refiled by the publisher; the battery did not change |
| Gorman BESS GU_404260 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 50 | refiled by the publisher; the battery did not change |
| Lumcloon ESS A-1 GU_407520 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 50 | refiled by the publisher; the battery did not change |
| Lumcloon ESS A-2 GU_407530 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 50 | refiled by the publisher; the battery did not change |
| Shannonbridge BESS (A1) GU_404380 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 50 | refiled by the publisher; the battery did not change |
| Shannonbridge BESS (A2) GU_404390 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 50 | refiled by the publisher; the battery did not change |
| Castlereagh BESS GU_503350 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 50 | refiled by the publisher; the battery did not change |
| Drumkee Storage GU_503950 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 50 | refiled by the publisher; the battery did not change |
| Mullavilly Storage GU_503960 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 50 | refiled by the publisher; the battery did not change |
| Kells Battery Storage GU_503980 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 50 | refiled by the publisher; the battery did not change |
| Southwall BESS GU_403600 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 30 | refiled by the publisher; the battery did not change |
| Kylemore BESS GU_403630 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 30 | refiled by the publisher; the battery did not change |
| Porterstown BESS GU_405070 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 30 | refiled by the publisher; the battery did not change |
| Kelwin Power Plant Phase 2 GU_404520 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 27 | refiled by the publisher; the battery did not change |
| Cloncreen BESS GU_407320 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 25 | refiled by the publisher; the battery did not change |
| Ballykilleen BESS GU_407550 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 20 | refiled by the publisher; the battery did not change |
| Aghada BESS GU_403560 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 19 | refiled by the publisher; the battery did not change |
| Avonbeg Storage GU_404530 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 16 | refiled by the publisher; the battery did not change |
| Bannbridge Main GU_504250 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 12 | refiled by the publisher; the battery did not change |
| BEEKTOBS GU_404010 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 11 | refiled by the publisher; the battery did not change |
| Killala Battery Storage GU_404550 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 11 | refiled by the publisher; the battery did not change |
| Gorey BESS GU_404540 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 9 | refiled by the publisher; the battery did not change |
| GU_404510 GU_404510 | fuel type | MULTI_FUEL | BATTERY_STORAGE | 8.5 | refiled by the publisher; the battery did not change |
August 2025, against July 2025
2 changes.
| Battery | What changed | From | To | MW | Our reading |
|---|---|---|---|---|---|
| Raghra 220KV GU_404650 | entered | · | · | 63 | new to this list |
| Ballykilleen BESS GU_407550 | entered | · | · | 20 | new to this list |
EirGrid’s contracted transmission generators
A battery enters when it signs a transmission connection agreement and leaves when it is energised or the agreement lapses; EirGrid replaces the list, so each capture is dated by the list’s own date. 1 capture held, 5 August 2026 to 5 August 2026.
One capture so far. The next read starts this ledger.
ESB Networks’ distribution lists
The five lists are read as one table, so a battery that moves from the contracted list to the energised list shows as a change of status rather than leaving one list and entering another. 1 capture held, 1 July 2026 to 1 July 2026.
One capture so far. The next read starts this ledger.