Mertaniemi
Operating, 38 MW · 43 MWh, in Lappeenranta, owned by Joint venture of Ardian Clean Energy Evergreen Fund and Lappeenrannan Energia. Every fact below is as a published source states it, with the address beside it; a field not shown is one no source gave, and nothing is guessed.
The battery
| Power | 38 MW |
| Capacity | 43 MWh |
| Duration | 1.1 hours |
| Status | Operating, as of 16 May 2025 |
| Owner’s date | 15 May 2025, actual |
| Municipality | Lappeenranta |
| Placed on the map | at the centre of Lappeenranta, its municipality (GeoNames) |
Who is behind it
| Owner | Joint venture of Ardian Clean Energy Evergreen Fund and Lappeenrannan Energia |
| Developer | eNordic (Ardian's Finnish platform) with Lappeenrannan Energia |
| Built by | Merus Power (EPC) |
A joint venture, no single business ID. Lappeenrannan Energia Oy is 1796558-9. YTJ lists Mertaniemen sähkövarasto Oy (3418266-6) by name only; no source ties it to this battery.
Not published anywhere we have found: ultimate owner, cells. The page says so rather than guessing.
What the sources say
Sizes differ by source: 38 MW / 43 MWh (commissioning release), 38 MW / 40 MWh (Merus bulletins 2024 and 2025), 38.5 MW / 38 MWh (Energy-Storage.news, Jun 2024). Optimised by Capalo AI (esn 25 Jun 2024).
Evidence and sources
From the owners’, developers’ and builders’ own releases, council decisions and permit bulletins, read by Vitreous and checked against the owners’ own words on 12 October 2026; a bracket such as “(Energy-Storage.news only)” in a field means the trade press is still the only source for it. Fingrid publishes no meter, no price and no instruction per battery, so this page carries no money: what one megawatt is paid in Fingrid’s markets is on the markets page, for the whole market and never for a named battery. List id FI-B008.