How a battery earns in Estonia

Estonia trades as a single bidding zone on the Nord Pool day-ahead market, run by TSO Elering. Since the Baltic states left the Russian grid and synchronised with Continental Europe on 9 February 2025, Elering operates its own frequency reserves — FCR and aFRR — and is procuring up to 500 MW of reserve capacity, opening a fresh revenue stack for batteries. Estonia offers no direct capex subsidy for standalone storage; the value comes instead from the market and from a 2026 grid-fee reform that bills network and renewable charges on net consumption only — worth over €3 million a year to a 100 MW BESS — while the DSO backs exempting ancillary-service storage from some tariffs. The core engine, though, is arbitrage: over the last 30 days the day-ahead spread averaged €99/MWh, or 201% of the average price — the daily gap a battery buys low and sells high into.

€99/MWh

Day-ahead spread — 201% of the average price (30 days)

500MW

FCR/aFRR reserve capacity Elering procures after the 2025 Continental Europe sync

€3M/yr

Grid-fee saving for a 100 MW BESS under 2026 net-consumption billing