In Flanders the digital meter ended the turning meter, so exported solar power is now paid at a low injection tariff while imported power costs 30 cents or more. Wallonia is following. Check what a battery would do with your own prices.
Starting values only. Your bill is the source of truth: enter your own import and export price in the simulator above.
| Typical import price | € 0.28 – 0.35 per kWh all-in |
|---|---|
| Export | Injection tariff of roughly € 0.03 – 0.06 per kWh with a digital meter |
| Solar yield | about 900 – 1,000 kWh per kWp per year |
| Battery prices | about € 500 – 800 per usable kWh installed |
Then exported power is still netted and a battery adds little. Select "Net metering (yearly)" above to see that case, and "Paid per kWh" for the digital meter.
Flanders bills part of the grid cost on your peak power. A battery can lower your peaks, which the simulator does not yet model; your saving may be slightly higher than shown.
For 3,500 kWh and 10 panels, 5 kWh is a common fit. Use the size table above with your own tariff.
Other countries: NetherlandsGermanyUnited KingdomIrelandFranceSpainItalyAustriaSwitzerlandAustraliaUnited StatesSouth Africa all countries
Change anything. Results update instantly. Pick a country for typical starting values, then type your own tariff from your bill.
Same roof and prices, only the battery changes. Bigger is not always better: once the battery covers your evenings, extra kWh sit idle.
| Battery | Battery saving / yr | Self-sufficient | Cycles / yr | Payback |
|---|
Every 15 minutes the simulator decides where each kilowatt-hour goes. Solar covers your use first, the surplus charges the battery, the battery covers your evening, the rest goes to or comes from the grid.
Your yearly kWh is spread over 365 days using a daily pattern for your profile: evening peaks for a home, daytime use for a business, more in winter than in summer.
Your panels produce a bell curve each day, long in summer and short in winter, scaled to the yield per kWp for your region. Nothing at night.
Every 15 minutes: solar covers your use first, the surplus charges the battery, the battery covers your evening, the rest is exported or imported. With 90% round-trip efficiency.
The same calculation runs on real smart-meter data in the WVE customer portal in the Netherlands: a virtual battery that follows a customer's measured 15-minute consumption for a month, with notifications and a report. Suppliers and installers can licence the engine for their own app, their own data and their own customers.
Free option: put the simulator on your own website in two minutes. Pricing for the engine starts with a pilot; software licence from € 995 per month including 100 simulations. We reply within two working days.