Largest battery developed within Nordic countries commissioned in Järvenpää, Finland

LinkedIn
Twitter
Reddit
Facebook
Email
As part of Fortum’s Batcave battery project, the lithium-ion battery storage system was installed in partnership with Fortum’s biomass-powered plant in Järvenpää. Credit: Fortum
The Batcave battery’s nominal output stands at 2MW, while the energy capacity is tabbed at 1MWh. Credit: Fortum

The largest battery ever developed within the Nordic countries has been commissioned at Fortum’s Järvenpää power plant in Finland.

As part of Fortum’s Batcave battery project, the lithium-ion battery storage system was installed in partnership with Fortum’s biomass-powered plant in Järvenpää.

The Batcave battery’s nominal output stands at 2MW, while the energy capacity is tabbed at 1MWh. The battery consists of approximately 6,600 lithium-ion cells, and it offers quick grid flexibility in frequency regulation.

Tatu Kulla, head of business development at Fortum, said: “Our Batcave project takes us a big step closer towards the solar economy, where electricity storage plays an important role alongside renewable energy production forms. The electricity battery brings flexibility to the national electricity market, benefitting all electricity users. In addition to storing electricity, the Batcave project allows us to test completely new ideas for optimal control of the battery together with other flexible electricity production forms.”

This article requires Premium SubscriptionBasic (FREE) Subscription

Try Premium for just $1

  • Full premium access for the first month at only $1
  • Converts to an annual rate after 30 days unless cancelled
  • Cancel anytime during the trial period

Premium Benefits

  • Expert industry analysis and interviews
  • Digital access to PV Tech Power journal
  • Exclusive event discounts

Or get the full Premium subscription right away

Or continue reading this article for free

The investment cost for the Batcave development project was listed at EUR 1.6 million, for which Fortum will gain a 30% energy investment subsidy from the Ministry of Economic Affairs and Employment. The electricity battery was supplied by French company SAFT, which has decades of experience in manufacturing various battery technologies.

Read Next

September 14, 2026
Lava Blue commissions Australia’s first grid-connected sodium-sulfur BESS, while ZEBRE’s 360MWh Noblevale BESS clears EPBC review.
September 10, 2026
A roundup of large-scale BESS news from in and around the Nordic region, with Sweden-based Flower building a project in Germany, Volvo launching one in Sweden and Delta Capacity securing a toll for one in Finland. 
September 3, 2026
Power firm Engie and IPP Grenergy are advancing three solar-plus-BESS projects in Chile.
August 28, 2026
A roundup of some of the best user-posted views, analysis and reveals from across the energy storage community in the past week.
August 27, 2026
A roundup of large-scale battery energy storage system (BESS) projects being financed, acquired or contracted in Poland, Lithuania, Latvia, Finland and Romania.