About Battery Payback

I’m Daan Haket. I built Battery Payback because I’m trying to answer the same question you are: is a home battery worth it, and if so, how big, which one, and when should you buy?

Why I care about this

We have 25 solar panels on our roof. Two years ago we put in a heat pump, and for the past year our home has run entirely on electricity, with no gas connection at all. A battery looks like the obvious next step. But almost everything I read answered a different question from the one I had. Sales pages tell you what a battery can do. Very few show you, with your own numbers, whether it actually pays for itself.

So the calculator takes your own usage, tariff and export rate, and shows each step of the sum.

I live in the Netherlands, not the UK, and our rules are different. UK rates, rules and specifications here are linked to their source and dated. They still have to be matched to the right tariff, model and region, and the calculator remains an estimate.

What you can expect

• Open sums. No hidden assumptions and no “up to” savings figures.
• A source for every figure. A short quote, a link and the date we read it. Anything we could not check is left out.
• No pretend testing. We have not installed or tested the batteries we describe. Battery guides are built from manufacturers’ datasheets and warranty terms, and we say so.
• Independence. We are not an installer, an energy supplier or a battery maker. Nobody pays to be listed and nobody sees our pages before they go live.

Who does what

I set the rules: which sources count, what goes on the site and what we will not claim. An AI assistant (Claude, made by Anthropic) does much of the legwork. It reads official guidance, tariff pages and datasheets, builds the calculator and drafts the pages. A second AI tool helps find sources. A script then fetches each source again and checks that the quote appears there word for word; a quote that cannot be found is not published. That proves the quote is copied correctly, not that we caught every condition attached to it.

I do not personally read every page before it goes live. When a mistake is found, it is fixed and listed in the corrections log.

How the site is paid for

Some links may earn us a commission in future, for example when you request installer quotes. Our policy is that it must not change the price you pay, and it never changes the sums on this site. The disclosure page says exactly where and how.

Corrections and questions

If a figure is wrong or out of date, please email daniel@batterypayback.co.uk with a link to the source. We fix it and date the change. We cannot give personal financial advice or quote for installations.