Posts
Home batteries, two stacked revenue streams
A 10 kWh home battery earns ~€730/year from spot arbitrage alone. Stacked with aggregated frequency-reserve revenue (only available via a BSP), the same hardware can clear above 10% IRR.
mFRR, where Estonian battery profits come from
Manual Frequency Restoration Reserve is activated by a human operator, with full delivery in 12.5 minutes. In Estonia, it is currently the most lucrative balancing market for batteries.
aFRR, the reserve in the middle
Automatic Frequency Restoration Reserve activates in ~30 seconds via TSO control signal, follows it on a 4-second cycle, and pulls the grid back to 50 Hz. Estonia joined the EU PICASSO platform on 9 April 2025; cross-border aFRR clears every 4 seconds across the continent.
FCR: what catches the grid when a reactor trips
Frequency Containment Reserve activates within 30 seconds of a frequency deviation, fully automatic, no TSO signal. Batteries dominate it. It is what made grid-scale storage economically viable.