Should your business invest in a battery?
Or have you already got an offer? We'll check it on your own consumption.
We model the battery on your own consumption from Eloverblik, your grid company’s tariffs, your grid connection and real Danish power prices — and give you a basis for the decision: the best battery for your connection, payback and net present value. An honest range, not one flattering number.
Many batteries stand or fall on grid services and the grid connection. Find out what applies to you — before you talk to a seller.
Solar on the roof — or on the way? We include it too, alone and together with a battery. And your CO2 from electricity for the climate accounts.
A home? See for free whether a home battery pays →
The answer is free. The full report and the tool: 399 kr for homes, 4,900 kr for businesses.
Independent calculation: we don't sell batteries and take no commission from suppliers, installers or aggregators.
The conclusion, the three numbers and the batteries side by side — amounts blurred. The whole calculation follows.
For businesses — and homes
Behind-the-meter batteries
Day-ahead trading, grid services (FCR, aFRR, mFRR) through a partner and lower demand charges — calculated hour by hour on a full year of your load and limited by your grid connection.
Value per year, payback, NPV and IRR for standard sizes or your supplier’s quote.
Plus your CO2 from electricity (scope 2) — hour by hour, location- and market-based, for your climate account.
A home battery — does it pay for itself?
We calculate what the battery saves by moving your use from expensive to cheap hours, with your grid company’s tariffs and taxes — and what it can earn on top through an aggregator that offers the battery to the grid’s reserve markets.
You get the payback time for common battery sizes, and we say so plainly if it doesn’t pay.
The free answer for homes
Yes, borderline or no — with what the battery can save a year, how many years it takes to pay for itself, and the most you should pay. Got an offer for a home battery? We check it on the same file.
For many homes a battery doesn't pay. Find out whether that applies to you — before you talk to a seller.
The free answer tells you where you stand. Here the answer is “borderline”: the battery pays for itself in the realistic case, but not in the conservative one.
Three steps, a few minutes
Give access to the consumption
Press the button above. From there you log in to Eloverblik with MitID and give Voltira access to the meter — it takes about a minute, and we fetch the consumption, grid company and connection ourselves. Prefer to download the files and upload them? You can do that too (see the guide).
We run the numbers
A full year of consumption, quarter-hour by quarter-hour, against the power prices and tariffs that actually applied — for several battery sizes. It takes a couple of minutes.
Read the basis for the decision
The best battery for your connection, payback, net present value (NPV) and internal rate of return (IRR) — and whether a bigger grid connection would pay. For homes: what the battery saves and how many years it takes to pay for itself.
The things most calculators leave out
- Your real tariffs. Your grid company’s time-of-use tariffs and demand charge, from the official DataHub price lists.
- Your connection. A battery can’t export or offer grid services beyond your grid connection.
- Reserve bids aren’t always won. We model win rates and show the range, not just the optimistic number.
- Prices are falling. Grid-service prices have dropped as batteries arrived; the outlook assumes they fall further.
- Batteries wear. Capacity fade, a yearly cycle budget and a wear cost on every kWh.
- Checked against the market. The engine is tested against known answers and an independent battery revenue index.
Free answer — pay only for the full report
Give access via Eloverblik or upload a file, and find out for free whether a battery — and solar panels — would pay at your place: yes, borderline or no, with the key numbers for one battery. Got an offer for a home battery? Check it free on the same file. No account, no card.
The full report is a tool you can keep calculating in: every battery size, the most you should pay, what grid services and solar add, your offer year by year (for businesses also after tax and with a loan) and recalculations with another battery.
Homes: 399 kr · Businesses: 4,900 kr · One-off payment, no subscription.
Know what the battery is worth to you before you talk to the supplier.
What people ask
Who pays you?
Only our customers. We take no commission or payment from suppliers, installers or aggregators — not per referral either. That's why we can say it plainly when a battery doesn't pay.
Does a home battery pay off?
It depends on your use, your grid company and the battery’s price. Our own calculations show that in many homes a battery does not pay for itself on own use alone within its life. Offered to the grid’s reserve markets through an aggregator, the picture can change. That’s why we calculate on your own data instead of quoting an average.
What data do I need?
Your consumption from Eloverblik, ideally a full year or more. The easiest way is to give us access with MitID: we then fetch your consumption, your master data (grid company, connection and settlement group) and — if you have solar panels — your production. The access lasts 3 months, and you can withdraw it at any time on eloverblik.dk.
You can also download the files from eloverblik.dk yourself and upload them: consumption (hourly or 15-minute values) and, with solar panels, production in the same export. The master data file is optional, but we recommend including it — the calculation becomes more precise.
What are grid services?
Energinet pays for capacity on standby to keep the grid stable (FCR, aFRR and mFRR). A battery can provide it — for homes and smaller businesses through an aggregator that pools many batteries and keeps a share of the income. For a home battery that means FCR west of the Great Belt and FCR-D east of it; aFRR and mFRR need large installations.
Do you include solar panels?
Yes, if you already have solar panels (beta). If you give us access via Eloverblik, we fetch both consumption and production (uploading yourself? select both in the export), and we see hour by hour what you buy and what surplus you sell. The battery is then calculated with all of it: it stores your surplus instead of selling it cheaply, buys cheap from the grid, sells stored power in expensive hours — and provides grid services through an aggregator if you choose. Elafgift follows the law: low in 2026–27 and back at the normal rate from 2028. If you are on annual net settlement (group 6), a battery saves very little, and the report says so plainly. If you don't have panels, the report also estimates what new panels would earn on your roof (beta): from your postcode, the roof's direction and EU solar data, hour by hour against your own use and real prices — alone and together with a battery. The same goes for businesses (beta): if you have panels, the battery is calculated with your surplus and the self-producer rules; if you don't, the report shows what panels on your roof would earn on your own tariffs — alone and together with the battery we recommend.
Does the report show the company's CO2?
Yes. The business report shows CO2 from electricity (scope 2): your use hour by hour times Energinet's environmental declaration for your price area. That is the location-based figure the EU's voluntary standard for SMEs (VSME) asks for. Enter how much of your use is covered by certificates of origin and you also get the market-based figure.
If you're considering solar panels or a battery, the tool also shows how much they change your CO2 — calculated honestly on your own consumption.
What happens to my data?
The file you upload — or the data we fetch from Eloverblik — is deleted as soon as the calculation is done. A free answer you don't buy is deleted after 48 hours. If you buy the report, it's kept in your account. More in our privacy policy.