The formula: how to calculate the payback time yourself
Payback time (years) = purchase price ÷ (usable capacity × cycles per year × efficiency × value per shifted kWh)
The price is above the fraction line. Below it is what the battery earns per year. Fill in the five parts with your own numbers.
| Part | What it is | Where to find it |
|---|---|---|
| Purchase price | What you pay, including installation and VAT | Your quote or the shop; VAT rules in what a home battery costs |
| Usable capacity (kWh) | What you can actually get out of it, not the nominal capacity | Product page or datasheet |
| Cycles per year | How often the battery goes completely full and empty per year | Depends on your generation, consumption and contract; often fewer in winter |
| Efficiency | Share of the stored electricity that comes back out (loss when charging and discharging) | Manufacturer's datasheet |
| Value per shifted kWh (€) | What you save because you use your own electricity later instead of feeding it back and buying it again later | Your contract: purchase price minus feed-in fee, plus feed-in costs per kWh if there are any |
First, the honest caveat
Want to know first whether a battery fits your situation? Take the profile check: is a home battery worth it?
Milieu Centraal expects that you most likely will not earn back a home battery at the moment. According to Milieu Centraal there is no national subsidy for a home battery. The formula shows where that can come from: in the example below the yearly return is small compared with the price. A battery can have other reasons, such as more self-consumption or less dependence on your supplier.
Worked example (all input is an assumption)
All numbers below are assumptions to show the calculation. They do not come from the shop and are not a price or return we promise.
| Input | Value in this example | Type |
|---|---|---|
| Purchase price | € 2,000 | assumption |
| Usable capacity | 5 kWh | assumption |
| Cycles per year | 250 | assumption (not full every day, especially in winter) |
| Efficiency | 90% | assumption |
| Value per shifted kWh | € 0.15 | assumption |
How sensitive is the result?
Same example, changing one input at a time:
| What changes | Yearly return | Payback time |
|---|---|---|
| Base (see above) | € 168.75 | approx. 11.9 years |
| 150 cycles instead of 250 | € 101.25 | approx. 19.8 years |
| € 0.10 per kWh instead of € 0.15 | € 112.50 | approx. 17.8 years |
| € 0.20 per kWh instead of € 0.15 | € 225.00 | approx. 8.9 years |
| Purchase € 3,000 instead of € 2,000 | € 168.75 | approx. 17.8 years |
What does independent research say?
Research firm CE Delft analysed a year of measurement data from home batteries in households for Vereniging Eigen Huis (report, January 2026). For two batteries that only controlled for self-consumption, the estimated payback time came out at 6.5 to 22 years. CE Delft bases the result on only two test setups. The amounts below apply to the situation without net metering.
| Situation in the research | Battery and price | Return over 12 months | Estimated payback time |
|---|---|---|---|
| Average consumption (3,600 kWh per year) | 5 kWh, € 3,500 | € 350 (fixed contract) / € 217 (dynamic) | 10 to 22 years |
| Very high consumption (approx. 11,000 kWh per year) | 10 kWh, € 6,000 to € 9,000 (including VAT) | € 947 (fixed) / € 602 (dynamic) | 6.5 to 14 years |
How this compares with the formula
CE Delft assumes a lifespan of 10 to 15 years. For an average household the payback time can therefore be longer than the battery's lifespan.
Put the numbers of the 5 kWh example into the formula: € 3,500 ÷ € 350 per year = 10 years. That is the lower end of the CE Delft range. With the return under a dynamic contract (€ 217) you get just over 16 years (€ 3,500 ÷ € 217 = 16.1). The formula and the real-world measurement point the same way: with average consumption the payback time is more likely around 10 to 22 years than below that. CE Delft only saw a shorter payback time in a household with very high consumption. CE Delft itself writes that a higher purchase price makes the payback time longer and a cheaper battery makes it shorter.
How many cycles do you get with your consumption?
A battery cannot shift more per day than you use in the evening and at night. A Dutch household uses on average 2,430 kWh of electricity per year, about 6.7 kWh per day (2,430 ÷ 365). A 5 kWh battery that goes full and empty every day would therefore have to cover most of such a day's consumption.
Use your own consumption from your annual statement or P1 meter if you have it; the average is only a fallback. About winter, CE Delft writes that there is little solar energy of your own in the winter months, so it is better to count the number of cycles cautiously. How to choose the capacity is explained in calculating home battery capacity.
Not sure which capacity fits? Try the battery match.
What determines the value per kWh after 2027
From 1 January 2027 net metering ends and you receive a reasonable fee for the electricity you feed back; until 2030 it must be at least 50% of the bare supply tariff. What changes is explained in net metering ends in 2027.
Every kWh you store yourself and use later, you do not have to feed back and do not have to buy again. After 2027 you pay energy tax and VAT on all electricity you draw, so your purchase price per kWh includes that tax. The value per shifted kWh is therefore: your purchase price per kWh, minus the feed-in fee per kWh, plus any feed-in costs per kWh. How that fee and those costs work is explained in feed-in costs and feed-in fee.
With a dynamic contract you can also shift between cheap and expensive hours; read home battery and dynamic contract. Whether a fixed or dynamic contract suits you better is explained in fixed or dynamic contract with a home battery.
What the formula leaves out
Wear: capacity declines over the years, so the yearly return falls. See lifespan and warranty.
Lifespan: if the payback time is longer than the lifespan, you do not earn it back. CE Delft uses 10 to 15 years.
Price changes: electricity prices, fees and feed-in costs change per contract and per year. That can move the result in either direction.
Interest or financing: if you borrow, interest costs come on top. More on paying and financing is in what a home battery costs.
The battery's own consumption (standby).
The formula therefore gives an indication, not a promise. Wear, interest and standby make the payback time longer, not shorter.
Compare the batteries in the shop with your own numbers.
Sources
- Milieu Centraal: Home battery, storing solar energy: home battery most likely not earned back at the moment, no national subsidy; last changed 28-09-2026 (accessed on 2026-10-18)
- Milieu Centraal: Average energy consumption in the Netherlands: on average 2,430 kWh of electricity per household per year; last changed 04-09-2026 (accessed on 2026-10-18)
- CE Delft: Test setups for home batteries. Vereniging Eigen Huis, January 2026 (publication no. 2026.240329.004): two test setups show a payback time of 6.5 to 22 years (accessed on 2026-10-18)
- CE Delft: Test setups for home batteries (pdf): section 2.3.1: 5 kWh, € 3,500, € 350 / € 217, 10 to 22 years; 10 kWh, € 6,000 to € 9,000, € 947 / € 602, 6.5 to 14 years; lifespan 10 to 15 years (accessed on 2026-10-18)
- Rijksoverheid: Net metering scheme ends in 2027: net metering ends from 1 January 2027; until 2030 fee at least 50% of the bare supply tariff (accessed on 2026-10-18)
- ACM ConsuWijzer: Net metering and feeding back: from 2027 a reasonable fee for electricity fed back; energy tax and VAT on all electricity drawn (accessed on 2026-10-18)
