Home battery in Brussels, Flanders and Wallonia

What does a home battery do?

Without a battery, much of your solar output is fed into the grid during the day, when nobody is home, then bought back in the evening at a higher price. Depending on the household, only 30 to 40% of the output is generally used directly. The battery stores this surplus and releases it when you need it, which significantly increases your self-sufficiency.

Most current batteries use lithium iron phosphate (LFP) technology, known for its stability and durability. They connect either to a hybrid inverter, which manages both the panels and the storage, or to a dedicated inverter when a solar system is already in place. The adviser checks the compatibility of your existing equipment before making any recommendation.

Does it pay off in Belgium?

Profitability depends on the gap between the price you pay for electricity and the price you are paid for what you feed in. In Flanders, where the meter no longer runs backwards and the capacity tariff rewards lower peaks, and in Wallonia, where new solar systems have not had net metering since 2024, every kWh stored rather than exported is worth more. Households that are out during the day and use most of their power in the evening benefit the most.

Conversely, a battery that is too large for your production or your evening consumption will sit partly unused. That is why we never assume that bigger is better: the adviser starts from your meter readings to estimate the useful capacity and a realistic saving.

Choosing the right capacity

For a house, 5 to 10 kWh generally covers an evening's needs. Beyond that, the benefit depends on the size of the solar system and on specific uses, such as charging an electric car or running a heat pump. Many systems are modular: you can start small and add modules later.

Some batteries can also provide backup power during an outage, provided the inverter supports it. Mention this need from the start, as it affects the choice of equipment and the wiring. The chosen location must also be ventilated, frost-free and accessible for maintenance, which the installer checks during the site visit.