Glossary
Imbalance energy (Ausgleichsenergie)
Also known as: Ausgleichsenergie, Ausgleichsenergiepreis, Bilanzabweichung, Imbalance price, Balancing energy settlement, Imbalance Energy
Ausgleichsenergie (imbalance energy) is the difference between a balance group's registered schedule and its actual consumption or actual feed-in in each settlement interval. Swissgrid covers this deviation with balancing energy and invoices it to the balance group manager at an imbalance price that follows the cost of the balancing energy activated. The fluctuating PV production of prosumers is one of the main causes of forecast errors; in 2024 it drove up the activation prices for secondary balancing energy (Swissgrid Balancing Roadmap).
The chain is simple: utilities buy energy on their own forecast, renewable generation causes forecast errors, forecast errors mean imbalance energy, and imbalance energy is supplied with balancing energy. A balance group that forecasts poorly pays for the balancing energy Swissgrid had to activate on its behalf.
That explains why feeding PV electricity back into the grid may cause costs in future: a utility that has to compensate for unexpected feed-in passes those costs on. And it explains why activated balancing energy has risen from around 700 GWh in 2020 to around 1’160 GWh in 2025 (ElCom).
Battery storage systems stand on the other side of this calculation: they deliver the secondary control reserve with which Swissgrid balances out the deviations, and are paid for it. The article Balancing energy with battery storage shows what the market paid in 2025.