Short answer
With solar panels the type of contract makes little difference from 2027: a 5 kWh battery saves an average household €242 a year on a fixed contract and €223 on a dynamic contract. Without solar panels, trading on hourly prices earns about €88 a year. That is too little to earn back a battery of €3,500.
How does a battery make money on a dynamic contract?
On a dynamic contract your electricity price follows the market every hour. A smartly controlled battery uses that in three ways:
- Keeping solar power for expensive hours. On a sunny afternoon electricity is worth almost nothing, in the evening a lot.
- Charging from the grid in cheap hours and using that electricity yourself during the morning and evening peaks.
- Not exporting at negative prices. The battery absorbs the surplus instead of you paying to feed it in.
Why trading through the grid earns little
Up to and including 2026, exported electricity is offset against purchased electricity, including tax. From 2027 that is no longer possible: you pay energy tax and VAT on every kWh you charge, and when you export it you only get the bare market price.
A worked example with a cheap hour at €0.02 and an expensive hour at €0.13 on the market:
| Per kWh charged | Amount |
|---|---|
| Charging in the cheap hour (market price + VAT + supplier fee + energy tax) | -€0.156 |
| Exporting in the expensive hour (88% comes out, at market price minus fee) | €0.106 |
| Result of trading through the grid | -€0.05 |
| Using it yourself in the expensive hour (you save the full purchase price of €0.289) | €0.254 |
| Result of shifting your own consumption | €0.098 |
Buying and selling again therefore makes a loss, even with a large price difference. Only electricity you use yourself makes a profit, and that is limited to your own consumption in the expensive hours.
Fixed or dynamic: the saving per household
| Household | Battery | Saving, fixed contract | Payback period | Saving, dynamic contract | Payback period |
|---|---|---|---|---|---|
| Small household | 2.5 kWh | €126 | more than 15 years | €115 | more than 15 years |
| Average household | 5 kWh | €242 | more than 15 years | €223 | more than 15 years |
| Family | 7.5 kWh | €358 | 13.3 years | €332 | 14.7 years |
| Heat pump and electric car | 10 kWh | €444 | 13.4 years | €431 | 13.9 years |
| No solar panels | 5 kWh | -€21 | more than 15 years | €88 | more than 15 years |
With solar panels most of the saving comes from the same thing in both cases: using afternoon solar power in the evening. The dynamic contract comes out slightly lower in our calculation, partly because we assume your inverter already stops exporting at negative prices, even without a battery. Which contract is cheapest without a battery is a different question that this calculator does not answer.
Which hourly prices do we use?
The calculator uses a price year tuned to the Dutch day-ahead market of 2025: €87 per MWh on average and 583 hours with a negative price, against 584 according to TenneT. The difference between the four most expensive and the four cheapest hours of a day averages €0.091 per kWh. You can change the average market price in the calculator.
What about the imbalance market?
Some providers control your battery for the imbalance market, where grid operator TenneT balances supply and demand at short notice. That can pay more than the hourly market. The income is not guaranteed, fluctuates strongly and falls as more batteries take part. Here too you pay tax on charged electricity from 2027.
That is why it is not part of the calculation. If you do expect income from it, enter it under 'Extra income per year', and any subscription fee under 'Costs per year'. That shows how much trading has to earn to make the battery pay off.
What should you look out for?
- Supplier fees. A fixed amount per kWh on purchases and sometimes on exports. They reduce the profit per charge cycle.
- Smart control. Without a controller that follows prices and the weather forecast, the battery does the same as on a fixed contract.
- Forecasts are not perfect. We therefore count 85% of the extra gain from smart charging.
- More charge cycles. A battery that also follows prices makes about 306 cycles a year instead of 197.
Choose 'Dynamic' in the calculator to work out your own situation, or first read what changes now that net metering ends.
Sources
- TenneT, Annual Market Update 2025. Average Dutch day-ahead price of €87 per MWh in 2025 and 584 hours with a negative price.
- Ministerie van Financiën, Tax Plan 2027 (in Dutch). Proposed energy tax on electricity in 2027: 8.80 cents per kWh excluding VAT in the first two brackets up to 10,000 kWh (2026: €0.09161). Bill from September 2026, not yet passed by parliament.
- Rijksoverheid, Net metering ends in 2027 (in Dutch). End of net metering on 1 January 2027 and the minimum feed-in compensation of 50% of the bare supply rate until 2030.
- Eneco, Vattenfall, Supplier explanations of feed-in from 2027 (in Dutch). How purchase and feed-in are billed separately from 2027, including feed-in costs.
- Belastingdienst, Home battery and VAT (in Dutch). A home battery carries 21% VAT; a refund is only possible in specific situations.