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How much does a solar park earn on the frequency markets? Real numbers from 10 MW
A 10 × 1 MWp solar portfolio earned €46,700 on the frequency markets in 2.5 months — and 77% of it came from the capacity market. See the real split and what it means per MW.
Frequency markets: get paid to keep the grid at 50 Hz.
Volton qualifies your battery, solar park or industrial load into FCR, aFRR and mFRR reserves and trades on your behalf. You keep the bulk of the revenue.
Solar parks and the frequency markets: the money is in capacity
A solar park earns on the frequency markets mainly from the capacity market — payment for keeping a reserve available, not for activation. And it qualifies without a battery. Here is how it works and how Volton takes a park to market.
The cheapest battery in your home is the boiler
A 100-150L hot-water tank stores 4-8 kWh as heat — about the same capacity as a small home battery. A €50 smart relay on the existing tank pays itself back within the first heating season.
Floor heating is the most flexible heater in your house
Resistive floor heating is in most Estonian homes and most of it runs dumb. The slab is essentially a thermal battery; price-aware scheduling captures spot-price spreads while the room temperature barely moves.
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.
When your solar panels lose you money
On a sunny April afternoon, a 10 kW rooftop array can produce 8 kWh and lose money in the same hour. Smart self-consumption + curtailment + battery routing is what makes solar pay in 2025 Estonia.
EV charging: plug in at six, leave at eight
A 50 kWh top-up costs about €15 at 02:00 or €45 at 18:00. Smart charging on OCPP-compatible wallboxes re-optimises every day against tomorrow’s spot prices, saving 50-70% on EV charging.
Heat pumps run on dumb thermostats
A heat pump is the largest steady electrical load in winter, paired with a thermal mass that doubles as a battery. Price-aware scheduling captures spreads of 5-10x between cheap night hours and expensive mornings.
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.