The Flemish home battery grant has been scrapped, and in 2026 there is no general grant for a residential battery anywhere in Belgium. The sales argument has shifted: with the end of the reverse-spinning meter, the battery is no longer an accessory but the way to raise self-consumption. Even so, the maths is tight — and a heat pump water heater driven by surplus often does better, for far less money.
No grant left: what that changes
Flanders ended its purchase grant for home batteries, and no other region has picked it up. In 2026 a residential battery is therefore bought at full price, with no direct public support.
What partly offsets this: the continuing fall in battery prices and the rise in electricity prices. What changed the reasoning above all: the disappearance of the reverse-spinning meter. As long as exports were offset at parity, storing had no point at all. That is no longer the case.
The real payback calculation
A battery does not produce energy: it shifts it in time. Its value is therefore the gap between the price of a kWh bought from the grid and the value of a kWh exported — multiplied by the number of kWh it actually manages to cycle each year.
That is where it pinches in Belgium. In summer, surplus is plentiful but evening needs are modest. In winter, when consumption climbs, solar output is too weak to cover both direct use and battery charging. The number of useful cycles per year therefore stays limited, and that figure is what drives payback.
⚠️ Be wary of simulations that look too good. A sales pitch showing a short payback almost always rests on three optimistic assumptions: an electricity price rising indefinitely, a battery running at full tilt all year, and a lifetime calculated without degradation. Ask for the guaranteed number of cycles and the guaranteed residual capacity at the end of the warranty — those are the only two figures the manufacturer actually commits to.
The capacity tariff and the prosumer tariff
Two regional mechanisms change the equation, and they pull in opposite directions.
- In Flanders, the capacity tariff charges for the peak power drawn from the grid. A battery that shaves those peaks — when the oven, the car and the washing machine run together — directly reduces that component of the bill. It is a very real argument, often underweighted against the pure self-consumption calculation.
- In Wallonia, the prosumer tariff is calculated on inverter capacity, not on what you export. A battery therefore does not reduce it: it does not act on the base of that charge.
Cheaper alternatives to storage
Before putting several thousand euros into a battery, two solutions shift consumption into sunny hours for a fraction of the price:
- The heat pump water heater driven by surplus — it turns the excess into hot water, a daily need. That is thermal storage, far cheaper than electrochemical storage.
- The home charging point driven by solar — if you drive electric, the car is already a large battery. Charging it during the day captures the surplus with no additional storage investment.
Neither covers evening needs, but both tackle the same equation on a far smaller budget. In most households they should come before the battery, not after.
Verdict
A battery is defensible if you already have a well-sized solar system, significant evening consumption, and — in Flanders — power peaks that weigh through the capacity tariff. It also provides partial autonomy during outages, which has a value that is not financial.
It is not defensible as a first investment, nor to "rescue" badly sized panels, nor on the basis of a payback promised by a salesperson with no quantified guarantee on cycle count. With no grant in 2026, the margin for error is thin.