Home Battery Profit Simulator
Calculate what a home battery earns you before you invest.
What do you want to calculate?
Outside Belgium and the Netherlands we use the simple version: enter your own electricity prices.
Tool version
Your data
Results
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Financial results
Fill in the data to get an analysis.
Annual savings on energy bill
Payback period
Total profit over the lifetime
Your best setup
Also calculating other battery sizes…
The calculator worked out one setup. Your best setup finds which combination of solar panels, battery and energy contract earns your house the most.
- How many solar panels and which battery size earn the most
- The best installed home battery by model, with a price including installation
- Fixed, day/night or dynamic tariff, each with its best way of charging
- How it turns out in good, average and bad price years
- A plain-language explanation to take to your installer
€ 10, once
Not useful? You get your money back.
Your Fluvius data can come along: when you sign up you can have it kept, so you don't have to upload anything again.
Coming soon: leave your email address and you'll be the first to hear.
Built by an energy engineer with 10 years of experience in the energy sector. No commission steers the advice. Our rules
Compared with batteries from 2.5 to 20 kWh, installed at a typical price: {fixed} plus {per_kwh} per kWh. How we calculate
Looking for the plug-in battery that earns you the most…
A heat pump or EV charger draws more than the few kW of a plug-in battery. This calculation includes that.
Through some links we receive a commission if you buy something. That changes nothing about the prices, the order or the calculation. How we make money
Advanced financial analysis (NPV, IRR, ROI)
Profit in today's euros
Net present value (NPV)
Annual return
Internal rate of return (IRR)
Total return
Return on investment (ROI)
Impact on annual consumption
Fill in the data to get an analysis.
Perform a calculation to see the results
Impact on annual energy costs
Perform a calculation to see the results
Energy cost breakdown
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Average daily profile over one year
Without battery
Perform a calculation to see the results
With battery
Perform a calculation to see the results
Feedback & Suggestions
Help me improve this tool by sharing your experiences, suggestions or questions.
What's new
- November 2026 New: the simulator also calculates for the Netherlands, with the rules after net metering ends (energy tax, feed-in payment, dynamic contracts). Choose the Netherlands, Belgium or World at the top.
- November 2026 New on the home battery overview: for each battery you see whether it follows your meter, can charge at fixed times and can play a dynamic tariff by itself, in its own app or through a supplier.
- November 2026 New: an energy tariffs page. Every electricity contract from Engie, Luminus and Eneco since 2022, calculated with a home battery: which contract gives the lowest bill?
- November 2026 New: calculate solar panels too, on their own or together with a battery. Choose at the top what you want to calculate and enter the panels' power and price; we add their production to your own consumption, quarter hour by quarter hour.
- November 2026 Fairer savings in the simple version: the capacity tariff is now counted separately, taking into account how the battery changes your monthly peaks, and the fixed costs per year no longer count per kWh. Don't pay a capacity tariff? Turn the new switch off.
- November 2026 New in the advanced version: calculate a plug-in battery of your own. Choose between an installed battery and a plug-in battery, which you plug into a socket yourself, without installation costs.
- November 2026 New on the home battery overview: a chart of each battery's price per kWh against the month it came on the market, so you can see whether newer batteries are cheaper.
- October 2026 New: under your result you see which plug-in battery earns your household the most, and whether it pays off. We compare all plug-in batteries in our overview for that.
- October 2026 New: if a battery doesn't pay off for you (yet), leave your email address under your result. When battery prices or tariffs change, we calculate your situation again and let you know whether a battery pays off then.
- October 2026 New: a home battery overview. Compare the power, capacity, efficiency and price per kWh of fifteen well-known plug-in and installed batteries.
- October 2026 New: the 'Find the optimal battery size' button. It calculates battery sizes for your household, down to 0.25 kW, and tells you which one pays off best, or that none does.
- October 2026 New in the advanced version: Time of Use and Optimized charging now also come in a capacity-tariff version. The battery then charges from the grid without raising your monthly peak.
- October 2026 The methodology and about pages are now available in English too, so English-speaking visitors can check exactly how the calculator works.
- October 2026 In the advanced version you can now set your battery's round-trip efficiency yourself: how much of the energy you charge you get back out.
- September 2026 New logo and a fresher look. The choices in the form now also work with the keyboard.
- September 2026 New: a page for businesses that want a tailored battery study, and a page for installers who want to work together.
- September 2026 You can now download your result as a PDF, including your assumptions and charts — useful to take to your installer.
- September 2026 The calculation now includes battery ageing: savings drop slightly each year as the battery loses capacity.
- September 2026 Fix for uploaded CSV files shorter than a year: the battery's savings are now also converted to a full year, and the battery works with your real quarter-hour values. The yearly savings used to come out too low.
- September 2026 You now choose whether we may use analytics cookies (Google Analytics). The calculator works the same either way. Change your choice at any time via 'Cookie settings' at the bottom of every page.
- September 2026 Clearer financial results: one overall verdict, the payback period and the total profit over the battery's lifetime. NPV, IRR and ROI now come with explanations under 'Advanced financial analysis'.
- September 2026 New menu on phones: the header now fits the screen, with all pages and the language switch one tap away.
- September 2026 Feedback button at the top of every page: share an idea or report a bug without leaving the page.
- September 2026 Set your own discount rate in the advanced version. The default drops from 5% to 3%.
- February 2026 New blog post (in Dutch): the rise of the home battery in Flanders.
- January 2026 The website is now also available in English.
- January 2026 New Fluvius consumption profiles (2024), now also for households with a heat pump.
- January 2026 Levies and contributions (energy contribution and federal excise duty) are now included in the calculation.