Jämsä (Winda Energy)
Announced, 50 MW · 100 MWh, in Jämsä, owned by Winda Energy. 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 | 50 MW |
| Capacity | 100 MWh |
| Duration | 2.0 hours |
| Status | Announced, as of 7 January 2026 |
| Municipality | Jämsä |
| Placed on the map | at the centre of Jämsä, its municipality (GeoNames) |
Who is behind it
| Owner | Winda Energy |
| Developer | Winda Energy |
| Business ID | 3168679-7 |
YTJ, by exact name: Winda Energy Oy. https://avoindata.prh.fi/opendata-ytj-api/v3/companies?businessId=3168679-7
Not published anywhere we have found: ultimate owner, built by, cells. The page says so rather than guessing.
What the sources say
Winda (7 Jan 2026): construction to start at the beginning of 2026, with Second Foundation; BHM Renewables leaves this project. Note 18 Oct 2026: the Czech embassy in Helsinki (31 Aug 2026) writes that construction at Jämsä began in early 2026, with Second Foundation; Winda's own news to 23 Sep 2026 carries no construction or commissioning release, so the status stays planned on the owner's word. https://mzv.gov.cz/helsinki/en/renewable_energy_and_data_centres_are.html
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-B049.