Mayo just cleared a revised plan for an 80 MW four-hour battery next to an SSE gas station - FID is still SSE's call
Mayo County Council granted planning consent for SSE's revised Mullafarry battery energy storage system near Killala - 80 MW / 320 MWh (four hours at full power), up to 64 storage units on an SSE-owned site next to the existing 104 MW Tawnaghmore power station. Delivery still hangs on SSE's final investment decision.
Ireland's northwest just got a clearer planning path for another grid battery - with the size locked in hours, not slogans.
Batteries News reports (25 Sep 2026) that SSE secured planning consent from Mayo County Council to revise plans for the Mullafarry Battery Energy Storage System near Killala, North Mayo. The approved project is an 80 MW / 320 MWh battery - four hours at full power by arithmetic - with up to 64 battery storage units plus heating, ventilation, air conditioning and supporting kit. The site is SSE-owned in Killala Business Park, next to SSE's existing 104 MW Tawnaghmore Power Station.
Consent is not the same as a build order. The page says delivery is subject to a final investment decision by SSE. If SSE green-lights it, construction is expected to take up to two years. SSE frames the box as reserve capacity the transmission system operator can call when the grid is tight - store when supply is high, release when the system needs power - and as local rates income for Mayo County Council once operating.
Analogy: planning permission for a cold store next to an existing plant. The council said yes to the revised footprint and size. The owner still decides whether to pour the slab.
Good: a published power and energy size (80 MW / 320 MWh), a published unit count (up to 64), a published neighbour asset (104 MW Tawnaghmore), and a clear gate still ahead (SSE FID). A buyer watching Irish grid storage gets a concrete project shape, separate from the SEAI panel grant and separate from the 1 October Generator Transmission Use of System charging change for batteries.
Bad: this is a transmission-facing grid battery on an SSE site, not a voucher on a factory-roof inverter quote. We will not invent your site's kilowatt-hours, your grant stack, or a payback from Mullafarry's planning paper.
Ugly: final investment decision is still open. Construction timing is "up to two years" only if SSE proceeds. Commercial rates and local jobs are framed as outcomes after operation, not locked invoice lines. We will not invent FID date, COD, or a workplace payback.
Soft next step: if your Ireland brief covers how a grid battery consent sits next to a workplace solar-and-battery quote, start with whether you are buying a roof box or watching system-operator reserve - then a short consult at Sovryn Energy /consult if you want that shape checked against your meter.
Source: Batteries News, 25 Sep 2026 - SSE secures planning consent for revised Mullafarry BESS in North Mayo. 80 MW / 320 MWh; up to 64 units; Killala Business Park next to Tawnaghmore 104 MW; subject to SSE FID. No site payback on that page.