Glossary
Energy management system
Also known as: EMS, Energiemanagementsystem, Energy management
An energy management system (EMS) is the control centre of a commercial energy installation: it monitors production, consumption and storage level in real time and coordinates the PV system, battery storage, flexible loads and charging infrastructure against economic targets. Typical functions are peak shaving, self-consumption optimisation and prioritised charging. Modern systems use load forecasts and machine learning to anticipate recurring patterns.
What does an EMS do in a commercial operation?
Without an EMS, battery storage and PV system remain isolated components. Only the overarching control layer decides in every 15-minute window whether the battery charges, discharges or stays in reserve for an approaching load peak, and thereby makes peak shaving and self-consumption optimisation possible at the same time.
The data basis is supplied by the grid operator: Art. 8a of the Electricity Supply Ordinance (StromVV) requires smart metering systems with an interface through which the end consumer can retrieve the measured values at the moment they are recorded, including the 15-minute load-profile values (ElCom, notice on metering under Art. 8a and 8b StromVV). In practice, the EMS additionally measures with its own meters at the grid connection point, because the control loop has to react sooner than the grid operator’s metering system delivers its values.
Which components does an EMS control?
Typical control objects in a commercial operation are the inverter of the PV system (curtailment under feed-in limits or negative prices), the battery storage system (charging and discharging power), the charging infrastructure (power distribution across the charging points), heat pumps and refrigeration plants (blocking periods and pre-run shifting) and individual large consumers with an enable signal. Communication runs via Modbus, OCPP for charging stations and the manufacturers’ interfaces; the EMS should therefore be planned manufacturer-independent so that later extensions do not fail on the protocol.
How does an EMS prioritise the applications?
Prioritisation follows the economics. Peak load capping takes priority because it directly lowers the demand charge: in 2026 a median of CHF 108 per kW and year for a 400 kW site (ElCom tariff data, analysis by Ampere Dynamic). After that, the system maximises self-consumption, serves downstream applications such as charging fleet vehicles according to the route schedule, and provides control reserve for Swissgrid in time windows with spare connection capacity. With dynamic tariffs, the supplier’s price signal is added as a further input variable.
Modern systems forecast load and PV yield from weather data and historical load profiles and schedule the battery ahead of time so that it is charged for the morning peak. How AI-supported systems forecast load profiles is explained in Energy management with AI; a realised example with 28 charging points and 1’001 kWp of PV is described in the Hugelshofer charging park.