Fingrid FCR Market Battery Saturation (2026)

Fingrid, the Finnish transmission system operator and counterpart of Svenska kraftnät, publishes its own data on how batteries have come to dominate its frequency containment reserves (FCR): the certified-capacity charts and yearly-market table on its FCR page (certified capacity as of 11 May 2026), its 3 Nov 2025 decision on the 2026 yearly market, a short passage in its 2025 annual report (dated 3 Mar 2026), and its April 2025 guide to batteries in the Nordic reserve markets. Four different documents are grouped here; published is the date of the latest data (11 May 2026). A comparator for The Swedish BESS Business Case — Revenue Stacking and the FCR Saturation Problem.

Reading scope: the FCR page text and charts, the news item and the battery report’s prequalified-volume tables were read in full; only the passages on reserve costs and the balance-service volume fee were read in the 182-page annual report.

Prequalified capacity by technology, 11 May 2026 (Fingrid charts)

Energy storage is the largest technology category in all three products. The same battery can be prequalified for more than one product, so the three storage figures cannot be added up to a fleet size.

Earlier battery volumes (Fingrid, April 2025)

Prequalified battery volumes on 1 January 2025 by country, from the April 2025 guide (columns Sweden, Denmark, Norway, Finland): FCR-D up 608.3, 18.1, 1 and 119 MW; FCR-D down 568, 18.1, 0 and 116 MW; FCR-N 297.2, 8, 0.4 and 106 MW. Finland’s battery volume in FCR-D up thus rose from 119 MW (1 Jan 2025) to 826 MW (11 May 2026) in about sixteen months, though the 2026 figure covers all prequalified storage and the 2025 table covers batteries.

Yearly market (Fingrid page and 3 Nov 2025 decision)

For 2026 Fingrid decided not to buy FCR-N on the yearly market, so FCR-N will come from the hourly market and from abroad; it says the reduced yearly volumes combined with growing total FCR procurement mean larger purchases on the hourly market and more cross-border trade. Prices are set by the most expensive accepted offer for each product.

Reserve costs (annual report 2025)

“Reserves securing the transmission grid’s operational security and power balance” cost EUR 189.2 million, down from 217.6 million, a change the report attributes mainly to a significantly increased supply of reserves on the market. Fingrid raised the balance responsible parties’ volume fee from 1.33 to 1.73 EUR/MWh from 1 January 2025 because of a major need to raise reserve capacity procurement early in the year, then cut it to 1.66 from 1 June and 1.35 from 1 September 2025 because reserve costs were lower than forecast.

What this source does not show

• It gives no fleet size and no hourly price series. A LinkedIn claim that more than 2 GW of Finnish batteries cut ancillary prices by about 90 % in three months in 2025 is not supported by these documents; Fingrid’s hourly price data would be needed. The Fingrid page lists open-data datasets for them.
• The charts are for prequalified capacity, not for capacity actually offered or activated.

Relevance to existing wiki topics

• The Swedish BESS Business Case — Revenue Stacking and the FCR Saturation Problem — Finland as a further point on the saturation path
• The Price-of-Flexibility Ladder — Why Capital Flows to FCR, Not Local Markets — the same capital flow into reserve markets
• Energy Storage — battery prequalification as the measure of market entry