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Privacy policy

Version 2026-10-29 · Draft, to be checked before the public launch

WattsWise shows what your home battery saves and, if you want, steers it by the electricity price. To do that it has to process some of your data. This page explains which data, why, and what your rights are. In short: we only use your data to run WattsWise for you. No ads, no tracking, no selling.

Who is responsible

WattsWise is run by Jeroen Priem, a private person in the Netherlands, who is the controller of your data under the GDPR (AVG). Contact: [email protected]. [Postal address: to be added]

What we process, and why

  • Your email address and a hashed password: to create your account, let you sign in and send you account emails (verification, password reset, invitations). Legal basis: contract.
  • Your household's name and settings (battery settings, feed-in terms, steering on or off): to make the plan and show your savings. Legal basis: contract.
  • The keys and tokens for Tibber, EcoFlow and SolarEdge: to read your data from those services, and (only if you turn steering on) to send settings to your batteries. Stored encrypted and never shown again. Legal basis: contract.
  • Energy data: electricity prices, meter readings from your Tibber Pulse, your batteries' charge level and power, your solar production, and the savings worked out from them: this is what WattsWise shows you and steers with. Legal basis: contract.
  • Device details: battery serial numbers and models, the name of your home in Tibber (or its street address when it has no name), and the type of browser or phone you sign in or turn on notifications with: to tell your batteries, your home and your sign-ins apart. Legal basis: contract.
  • Your household's rough location, to about 10 km (taken from your Tibber home, or set by you): to fetch the sun and cloud forecast for your area from Open-Meteo. Only this rounded point is sent, by our server, never your address. Legal basis: contract.
  • Push notification subscriptions for the devices where you turn notifications on: to send the notifications you chose. Legal basis: your consent (you turn them on and off per device).
  • What you agreed to and when (these terms, the steering disclaimer): to show what you accepted. Legal basis: legal obligation and legitimate interest.
  • Error reports (what went wrong in the app or on the server, with your household's number but without your email, keys or IP address): to find and fix bugs. Legal basis: legitimate interest.

We don't use your phone's location, contacts or anything else from your phone beyond the above. Your IP address is only held in memory for a short while to stop people guessing passwords; it isn't stored.

Where your data is

All data is stored in the European Union. We use these processors, each under a data processing agreement:

  • DigitalOcean (servers, Amsterdam, the Netherlands)
  • Neon (database, Frankfurt, Germany)
  • SMTP2GO (sending emails, EU region)
  • Sentry (error reports, Frankfurt, Germany)
  • Apple, Google and Mozilla deliver push notifications to your device; they only see an encrypted message

Tibber, EcoFlow and SolarEdge are services you connect. WattsWise reads your data there with the keys you give, and their own privacy policies apply to what they hold.

How long we keep it

  • Minute-by-minute readings for 60 days. After that they're averaged per quarter of an hour, and those averages are kept as long as you have an account, so you can look back at your savings.
  • Everything else is kept as long as you have an account.
  • Sign-ins expire after 60 days without use. Links in emails expire after an hour (password reset), a day (verification) or a week (invitations).
  • Error reports are kept by Sentry for 90 days at most.
  • When you delete your account, your data is deleted right away. If you're the owner of a household, that includes the household's energy data. The database keeps a restore history of 6 hours, so after that nothing of it can be brought back.

Your rights

You can:

  • Download all your data: Settings → Download my data.
  • Delete your account and its data: Settings → Delete account.
  • Correct your details in Settings, or ask us to.
  • Object to processing, or ask for it to be limited, by emailing [email protected].
  • Complain to the Dutch data protection authority, the Autoriteit Persoonsgegevens (autoriteitpersoonsgegevens.nl).

We answer requests within a month.

Household members

If you invite someone into your household, they see the same energy data and settings as you. A member can leave at any time; the owner can remove members.

Changes

If this policy changes in a way that matters, we'll tell you in the app before it takes effect. The version and date are at the top.