Measure,
decide,
control.
An Energy Management System — EMS for short — continuously measures, evaluates and actively controls the energy flows inside an installation. It makes sure energy goes to the right place at the right moment: charging or discharging a battery, starting or stopping a generator, throttling EV chargers, or diverting a solar surplus to the thermal buffer instead of the grid.
What is an EMS?
An EMS is not a passive monitoring system. It is an active control system that combines real-time data from sensors, meters and inverters with business rules, price information and grid constraints, and uses it to automatically control batteries, generators, charging infrastructure, solar inverters, heat pumps, boilers and other devices behind the meter. The goal: use energy smarter, prevent peaks, lower costs and — where possible — earn back the investment.
Monitoring versus control
Simple monitoring only lets you see what is happening. A full-fledged EMS acts. The moment a sensor signals that the grid is nearly full, that solar yield is peaking or that the power price has gone negative, the EMS executes a planned action within seconds — without any human intervention.
The control loop. From measurement to action.
Every EMS works along the same three-step cycle. This loop runs continuously — often several times per second — and keeps your installation in balance with the actual conditions at any given moment.
Sensors & data
Current and power readings, voltage, frequency, temperature, battery SOC, inverter status, weather data and energy prices. Everything is read out at high frequency via industrial protocols.
Rules & logic
The EMS evaluates the measurements against your objectives: maximise self-consumption, avoid exceeding the grid connection capacity, charge during low prices, prevent grid congestion. The result is a concrete setpoint or command.
Actuators & devices
The command is sent to the right actuator: battery (charge / discharge / standby), generator (start / stop), EV charger (power limit), inverter (curtailment), three-way valve to the thermal buffer, or switch.
What does an EMS actually control?
Six typical scenarios in which an EMS intervenes autonomously. In practice they run simultaneously — the EMS juggles everything connected behind your grid connection.
Charge on surplus, discharge on peak
When PV produces more than is being consumed, the EMS charges the battery. As soon as consumption rises above a threshold — for instance during cooking peaks or production runs — it switches to discharging and prevents expensive peak load from the grid.
Automatic start and stop
At low battery state of charge combined with unfavourable grid prices, the EMS starts a diesel generator or CHP unit. As soon as PV production or cheaper grid power is sufficient again, the generator is cleanly ramped down and switched off.
Dynamic power limiting
The EMS distributes the available power across multiple EV chargers and throttles them dynamically. As the load on the grid connection rises, chargers are allocated less power — without tripping the main fuse or exceeding peak tariffs.
Throttling the solar inverter
During grid congestion, negative power prices or a full battery, the EMS throttles the PV inverter(s) to a lower output. Briefly producing less is preferable to selling at negative prices — or worse, being forcibly disconnected by the grid operator.
Surplus to boiler or heat pump
Instead of giving away free solar energy at a zero or negative tariff, the EMS routes the surplus to an electric boiler, heat pump or thermal buffer. Result: free hot water or heated spaces — storage in thermal form.
Peak shaving at the connection
Your contracted capacity (€/kW/month) is often one of the largest cost items. The EMS keeps the load below a configured ceiling by smartly activating battery, generator or non-critical devices — avoiding expensive overshoot penalties.
Where does the data come from?
An EMS is only as good as its data stream. In a typical installation, dozens of data points are read — from the main meter down to individual inverters.
Main meter
kWh meters and kW transducers at the grid connection measure the net exchange with the grid.
Modbus RTUInverters
PV inverters (SMA, Sungrow, Huawei, SolarEdge, GoodWe and others) deliver power, energy and fault codes.
Modbus TCP · FTPBattery / BMS
State of charge, power, cell voltages, temperature and available capacity.
CAN · ModbusCurrent transformers
CT clamps measure — per circuit group or per phase — exactly what is flowing through the cable.
Analog · ModbusWeather data
Local solar irradiance, temperature and wind speed — feeding performance-ratio calculations.
API · SensorEnergy prices
Day-ahead and hourly spot-market prices (EPEX) drive the charge and discharge strategy.
REST APICharging infrastructure
Statuses and setpoints of EV chargers via OCPP — for dynamic load management.
OCPP 1.6/2.0PLC / SCADA
For industrial installations the EMS ties into existing PLCs and building-management systems.
OPC UA · ModbusWhat does it deliver?
An EMS pays for itself in three ways: through lower grid costs, higher self-consumption, and greater yield from your existing installations.
Lower grid costs
Peak shaving reduces your contracted peak capacity. For large consumers, a lower peak translates directly into a lower grid connection fee — the exact saving depends on your grid operator's tariff structure.
Higher self-consumption
By storing PV surplus in a battery or thermal buffer you use what you generate yourself — instead of feeding it back at low or negative prices.
Price arbitrage
The EMS charges batteries at low dynamic tariffs and discharges them during peak hours. The price difference between off-peak and peak is captured directly.
Congestion-proof
Working with a capacity-limited contract or a cap-and-trade arrangement due to grid congestion? The EMS automatically stays within the agreed limits, 24/7.
Less curtailment loss
Smart diversion to heat, EVs or battery prevents you from having to dump solar energy — yield you would otherwise lose.
Insight & control
Beyond automatic control, an EMS delivers a full dashboard with performance, yield and alerts — the foundation for reporting to investors and grid operators.
The new Elteq-EMS platform, in a single portal.
From September / October 2026 we are launching the renewed Elteq-EMS platform, built on the 1AITE energy-intelligence stack. One environment for monitoring, control, finance and reporting — across your entire portfolio. Plug-and-play hardware inside your switchboard, paired with a portal that is ready for battery control, dynamic tariffs, congestion management and automatic reporting.
An EMS is the difference between knowing your installation is running — and being certain that every kWh reaches the right place at the right moment.