Capacity calculation
How many kWh does your home battery need?
Get an initial capacity indication from annual usage and, if known, solar array capacity in kWp. See the assumptions and limits before requesting advice.
Or start the free calculator · Completely no obligation
Request personal capacity advice
Ask an installation partner to assess your consumption and installation. You can send an advice request without a calculator result.
- Short capacity check
- Quick to fill in, instant initial indication.
- Initial capacity range
- Your consumption is the starting point.
- You give consent
- Submitting an advice request requires your consent.
The calculator
A starting point for battery capacity
The compact check gives a range for solar storage. If data is missing, it explains what is still needed. Consumer-unit checks and financial assessment belong in follow-up advice.
- Capacity range based on annual usage
- Separate indication when solar output is known
- Clear assumptions and limits
- No contact details needed
Instant insight with our calculator
Your first estimate
First size choice
Based on your input
Store for later
Guideline, not a guarantee
First sizing indication based on your answers.
Why calculate first?
A home battery can be interesting, but not in the same way for every household. The right capacity depends on your solar panels, usage, energy contract and when you use power. With the calculator you get a clear sizing indication first, without being tied to anything.
More insight
Get an initial range and see which data is still needed.
No obligation
You do not need to leave your details to see the initial calculation.
More targeted advice
Want to go further? We can give more personal advice based on your results.
Capacity per kWh
Each size fits a different situation. Compare common capacities and discover which home battery fits your usage and solar panels.
- 5 kWhWhen should you consider 5 kWh?If you already use much of your solar power during the day, less surplus remains to fill a battery. Even with a compact size, check what you actually export.
- 10 kWhWhen should you consider 10 kWh?Compare smart-meter readings across several days. An annual total hides the difference between a sunny afternoon and a winter evening.
- 15 kWhWhen should you consider 15 kWh?Is your heat pump or car already included in annual consumption? Do not add a fixed allowance on top. New equipment needs a separate estimate.
- 20 kWhWhen should you consider 20 kWh?High winter consumption and strong summer generation do not coincide. More kWh does not provide summer-to-winter storage or make you self-sufficient.
Or read more about home battery with solar panels
Lots of solar power generated, but little used yourself?
Many households feed power back to the grid during the day while needing electricity in the evening. A home battery can help use more of your own solar energy. Whether it makes sense for you depends on your home, usage, panels and contract.
That is why we start with a capacity calculation based on your situation.
How the capacity calculation works
- Step 1
Enter your situation
Answer questions about your home, solar panels, electricity use and energy contract.
- Step 2
Receive a sizing indication
Get a range with an explanation. If data is insufficient, see why further advice is needed.
- Step 3
Optional: request advice
Want more detail? Request personal advice with no purchase obligation.
Indicative result · No purchase obligation
Why people calculate via thuisaccuKWH.nl
A home battery is an investment. You want to know which capacity fits, what it costs and under what conditions it makes sense. We help you with clear sizing criteria first.
Free and no obligation
The check costs nothing and commits you to nothing.
Advice based on your situation
A simple guideline using your input, including the limits of an initial check.
You choose what to share
The advice request is intended for installation partner SolarFast. The form shows which details you share and asks for consent before sending.
Honest assessment
Insufficient data or an unclear result? There is no forced product choice.
A well-founded sizing choice starts with the right input.
What can a home battery mean for you?
A home battery can store some solar surplus for later in the day. How much you use depends on daily generation and consumption. A larger battery is not automatically better.
- Use solar power later in the day
- Match capacity to your surplus
- Assess storage and charging power separately
- Understand your usage pattern
- Discuss expansion options
- Have your installation assessed
A first sizing indication within minutes.
Smart with energy prices
Dynamic tariffs need a separate assessment
Charging and discharging based on tariffs needs suitable controls and an assessment of costs and losses. The capacity check does not calculate trading income or payback.
- Check the contract and tariff structure
- Account for charging and discharging losses
- Assess the control system
- Do not assume guaranteed returns
Illustration of tariff periods
Lower tariff
Low
Higher tariff
High
Smart consumption
Own power
Personal advice
Calculate first, then leave your details
Want a closer assessment of your initial indication? After the check you can submit an advice request with your consumption and requirements. You decide whether to send it.
- Add your consumption details
- Indicate what you would like assessed
- Request advice without a purchase commitment
- Sending requires your explicit consent
Who is a home battery especially relevant for?
Homeowners with solar panels
You generate during the day and want to use that power later.
Households with higher usage
For example due to electric cooking, AC, heat pump or EV.
People with a dynamic energy contract
You want to respond to cheaper or more expensive periods.
If you see net metering ending
You want to use more of your own solar power instead of feeding everything back.
Not every home battery fits every home
The right choice depends on usage, panel count, inverter, contract and future plans. A well-founded sizing choice matters more than brand or price alone.
- What capacity do I need?
- Does the battery fit my current installation?
- How much of the capacity can I actually use?
- Which brands and solutions are suitable?
- Install now or wait?
Installation & safety
A battery that fits your home
Choosing takes more than a kWh figure. The installation partner assesses your consumer unit, inverter, location and requirements. The online check gives a capacity indication only.
- Assessment by an installation partner
- Check connection and inverter
- Compare usable capacity and power
- Discuss backup power separately
Installation & safety
Checks before installation
To assess
To assess
To assess
- Have installation assessed
- Check the connection
- Match capacity to usage
- Advice before choosing
Frequently asked questions
Start with annual consumption and solar panel output. An initial guideline is 60 to 80% of average daily usage. The check shows this range and, when solar output is known, a separate solar indication. There is no fixed size for every family.
Yes. You see an initial indication without leaving contact details. You can then request personal advice at no obligation. The check does not commit you to a purchase.
Your advice request is intended for installation partner SolarFast. You can request an assessment of capacity and technical options for your home. Sending requires your consent. This website does not compare installers.
No. kWh is an amount of energy: how much you store or use. kW is power: how quickly energy can be charged or delivered. Check both, because more storage does not automatically mean all appliances can run together.
Questions that help with sizing
You generate more during the day than you use straight away. The battery keeps part of that for the hours after sunset.
You want to see a capacity range and understand its basis first. Then decide whether to request advice.
If you already use these, their consumption may be in your annual total. If equipment is planned, have that change assessed separately.
Ready to discover if a home battery fits your home?
Calculate an initial range from annual consumption and solar panels. You can then request further advice at no obligation.
Start the free calculatorShort check · Free advice · No obligation