Ancillary services: battery revenue explained

FCR-D, FFR and aFRR explained. How your battery storage delivers balancing to Svenska kraftnät and earns revenue beyond shaved power peaks.

Frequently asked questions

What are ancillary services to the power grid?

Svenska kraftnät (the Swedish TSO) compensates operators who help keep the power grid stable at 50 Hz. A battery storage system can respond in seconds and is therefore well suited to delivering balancing services. The revenue comes on top of the battery's other benefits, such as shaved power peaks.

What is the difference between FCR-D, FFR and aFRR?

FCR-D (Frequency Containment Reserve – Disturbance) activates automatically at frequency disturbances and requires a battery with a high C-rate. FFR (Fast Frequency Reserve) is the fastest reserve, activating in under a second to catch sudden frequency drops – batteries are one of few technologies fast enough. aFRR (automatic Frequency Restoration Reserve) automatically restores the frequency after a disturbance and is managed by the EMS system, which handles bidding and activation.

Can my battery storage deliver ancillary services and shave power peaks at the same time?

Yes. The EMS system optimises the battery against both consumption forecasts and the ancillary services market, meaning revenues are built on multiple legs: ancillary services, arbitrage and lower grid fees. The different services complement each other and maximise the value of the battery.

How much can a battery storage system earn from ancillary services?

The revenue depends on the market, the battery's power output (C-rate) and availability. We help you calculate the potential for your specific system. Current market conditions are available from Svenska kraftnät.