Privacy

The short version: your electricity data is read in your browser and never sent to us. We don’t use tracking cookies and there are no accounts.

Your half-hourly CSV

The file you upload on the “Your usage” step is parsed entirely in your browser. It is summarised into an average-day profile and kept in your browser tab’s session storage, which is cleared when you close the tab or press “Start over”. The raw half-hourly readings themselves are kept only in memory, for that same tab, so the tariff and results steps can price them exactly rather than from the averaged profile; they are never written to storage or transmitted, and are gone if you refresh the page or close the tab.

Postcode and tariff

Your postcode is sent to two services to run the estimate: postcodes.io (to get coordinates) and the EU PVGIS service via our server (to get local solar yield). We cache the yield result by location so repeat lookups don’t hit PVGIS again; we don’t log who asked for it. Your tariff rates stay in your browser alongside the usage summary.

Analytics

We use Vercel Analytics to count visits and see where people leave the four-step flow. It is cookieless, sets no persistent identifier, and the events we record carry only coarse values — a step name, whether a lookup succeeded, rounded usage bands, kit interactions and campaign labels such as LinkedIn or Facebook. No postcode or exact consumption figures are sent in analytics events.

If something breaks in your browser, we record that it happened, the general kind of error (for example a TypeError), the step you were on, and the browser family (for example Safari on iPhone or the Facebook app). We never record the error message, what you typed or uploaded, or your postcode.

The feedback form

If you send feedback, your message (and your email address, if you choose to give one) is emailed to us so we can read and reply. If you tick “attach my inputs” — off by default — the message also includes your postcode, the usage summary figures and your tariff, to help us reproduce a problem. It never includes your raw half-hourly data. These emails sit in our inbox; tell us if you want yours deleted.

Marketing updates

On the contact page, ticking “keep me posted” adds your email to a mailing list in Resend, our email provider, used only to send you Little Solar updates. Every email carries an unsubscribe link, and asking us removes you.

Contact

Use the contact page or the feedback button on any page. This page will move to a fuller notice before any wider launch.

Last updated 21 September 2026.