Glossary
Balance group
Also known as: Bilanzgruppe, Bilanzgruppenverantwortlicher, BGV, Balance group manager, Balance Group
A Bilanzgruppe (balance group) is a grouping of feed-in and offtake points in the Swiss electricity grid for which a balance group manager, usually a utility or an energy trader, registers schedules with Swissgrid. The manager procures the energy in advance in hourly blocks based on its own forecasts. Where real consumption or PV production deviates from that, imbalance energy arises, which Swissgrid invoices to the balance group. As the PV share grows, forecast errors increase and with them the need for balancing energy.
A balance group’s schedule is a staircase of hourly blocks. Real consumption runs as a curve around that staircase, and Swissgrid has to balance out every deviation with balancing energy. Utilities therefore buy energy based on their forecasts; they pay for the forecast errors as imbalance energy.
Two developments sharpen this. On a cloudy day, PV feed-in collapses within minutes and jumps back up, while a clear day delivers a smooth bell curve. And prosumers switch several times a day between drawing from the grid and feeding in, which makes the load profile unpredictable from the balance group’s point of view. Activation prices for secondary balancing energy rose in 2024 for exactly this reason (Swissgrid Balancing Roadmap).
For businesses with battery storage, that is an opportunity: the larger the forecast errors, the more balancing energy is activated. How a storage system earns from this is explained in the article Balancing energy with battery storage.