Finland has 2,057 MW of batteries connected, by Fingrid’s own count, and nobody publishes which they are. Their owners name 393 MW of them, and 1,434 MW more being built.

Fingrid’s count rose 841 MW in 7 months, and four arrivals of 60 MW or more carry 554 MW of it

Fingrid adds a battery to its network model up to a month before it starts, so each step in this line is a battery, or a batch of them, arriving on the grid; it does not say which. The count opened at 1,215 MW on 11 March 2026, the first hour Fingrid published it, and stood at 2,057 MW on 16 October 2026. Between the big steps the line climbs in small ones, many of exactly 1.25 MW, which is the size of one container battery.

Fingrid, dataset 424, “Total installed battery energy storage system capacity”, hourly, read 16 October 2026, CC BY 4.0. Fingrid’s figure counts storage of a megawatt or more, including units expected to connect within about a month, with the distribution grid’s part depending on what the distribution companies document. 3 one-hour readings in which the feed fell to a fraction of the hour before and came straight back are left out as faults in the feed. The dated steps are on the change ledger.

The best hour by hour stack paid one megawatt €17,621 in October 2025 and €13,339 in September 2026

Finland’s batteries earn mostly by holding reserve for Fingrid: FCR-N, FCR-D, aFRR and mFRR, each bought in an hourly market whose price and volume Fingrid publishes. The bars are the most one megawatt could have been paid each month with perfect hindsight, choosing the best product every hour, before any cost; a real battery earns less. Over the twelve months to September 2026 that ceiling was €127,090 for the megawatt, of which FCR-N alone would have paid €79,655.

Calculated by Vitreous from Fingrid’s hourly reserve prices and volumes (CC BY 4.0), read 16 October 2026; a price counts only in an hour in which Fingrid bought something. The grey bar is a part month. Energy trading on the day-ahead and intraday markets is not in these figures, because Nord Pool’s prices may not be shown here. Every market, month by month, and how each figure is made.

The markets are filling up: 5.5 megawatts of batteries for every megawatt of upward fast reserve Fingrid bought in October 2026, from 4.0 in March 2026

Fingrid buys a roughly steady amount of upward fast reserve each hour, in FCR-N, FCR-D up and FFR together, while the batteries able to sell it keep arriving. The ratio of its installed battery total to the upward reserve it bought in the same hours is the plainest measure of how crowded the market is getting, and the line only goes one way.

Each month, the average of Fingrid’s installed battery total (dataset 424) divided by the average upward volume it bought in its hourly FCR-N, FCR-D up and FFR markets (datasets 316, 315 and 276) in the same hours. Fingrid, CC BY 4.0. The table of the ratio month by month is on the markets page.

Where the named batteries are

One circle per battery named by its owner, at the place its name carries or the centre of its municipality, sized by power. Yellow operates; blue is being built; pale blue is announced.

69 of 77 batteries placed, every one from GeoNames because no source gives coordinates; 8 have no municipality in any source and are not drawn. 393 MW operating, 1,434 MW being built, 1,654 MW announced.

Every battery named as operating

As the owner, developer or builder states it in its own release; the date is the owner’s stated start. Kauhava is energised and commissioning, not yet in commercial operation, and is counted here with the operating batteries. Every figure’s source is on the battery’s page.

Being built

The owners with the most operating

Who builds them

Merus Power is named on 12 of the 77 batteries; the list names a builder or integrator for 42 of them. Nobody names the cell maker: no source read says whose cells are in any Finnish battery.

What is not here, and why

Which batteries make up Fingrid’s count, because no Finnish body publishes a unit list; the 1,663 MW the named list does not reach is, by Fingrid’s own February split, mostly units under 2 MW. What each battery earns, because Fingrid publishes the markets and not the bidders, so the money on this site is for one megawatt and never for a named battery. The day-ahead price, because it is Nord Pool’s and Nord Pool declined permission to show it. Coordinates, because no owner publishes them, so every point on the map is a GeoNames place. The connection queue, because Fingrid publishes enquiries only as totals and a map of where new storage may apply. A connection figure is never passed off as a battery’s size.

Sources: Fingrid Oyj open data, data.fingrid.fi, datasets 424 (installed battery capacity), 316 and 317 (FCR-N), 318 and 315 (FCR-D up), 283 and 281 (FCR-D down), 52, 51, 1 and 2 (aFRR), 329, 330, 327 and 328 (mFRR), CC BY 4.0, read 16 October 2026. The named batteries from fi/hand/batteries.csv, kept by hand from owners’, developers’ and builders’ own releases, council decisions and permit bulletins, every fact with its web address, checked against the owners’ own words on 12 October 2026. Places from GeoNames, CC BY 4.0. Fingrid’s February 2026 split of its count by size from its release of 24 February 2026. Nothing on this page is modelled.