App & website

Privacy policy

Last updated: 2 November 2026

This is a translation. In case of discrepancies, the German version prevails. Deutsche Fassung

Controller

Data on your device

Solar String Check has no account, advertising, analytics, tracking or third-party SDKs. The Powerwall Wi-Fi name and the details of your system (input names, number and orientation of modules, module power) are stored in the app settings, the password in the iOS Keychain and your measurement history in the app. The history holds the values of every string and, where the Powerwall reports them, consumption, grid import and feed-in, solar power, and the battery’s charge and capacity. These are stored only on your device. In History, you can delete individual measurements or use Delete Entire History.

When you tap Get Readings on site or start continuous logging, the app joins your Powerwall 3 Wi-Fi, reads directly from the device and leaves the network afterwards. There is no cloud or server between the app and the Powerwall. iOS asks for permission to join the Wi-Fi each time. There are no automatic background measurements.

In-app purchase

The app is free to download. The demo is always free, and so is your first reading that shows values from your Powerwall. Further readings and continuous logging need a one-time in-app purchase. Apple processes the purchase and payment in the App Store under its own terms; the developer receives no payment details, names or email addresses. The app asks the App Store on your device whether the purchase exists, to unlock it and to restore it on your other devices or through Family Sharing. Whether the free reading has been used is stored only on your device.

Optional error reports

If the Powerwall responds but the app cannot use the response, the cause may be in the app. In that case, the app asks once whether it may automatically send future error reports to the developer to investigate and fix the problem. No reports are sent for Wi-Fi, range or password problems.

What a report contains

• App and iOS versions, language, time and trigger.
• Every step of the query, with status, duration and error.
• The raw responses from the Powerwall and the values read from them, including battery, consumption, grid and Tesla’s alert codes.

The password is never included. The device ID (DIN), serial numbers, Wi-Fi name and the session ID of Tesla’s remote service are redacted. Reports contain no names, addresses, location data, device identifiers or advertising identifiers.

Your choice

Under System → Show Support Report, you can view a report, send it yourself or pass it on using the share menu. You see a manually sent report in full before sending. Automatic reports are sent after your one-time consent without another prompt.

The legal basis is your consent under Article 6(1)(a) GDPR. You can withdraw it at any time by turning off System → Send Error Reports Automatically. Withdrawal does not affect the lawfulness of processing before withdrawal.

Delivery and retention

Reports are sent by HTTPS to https://api.solarstringcheck.com, a Cloudflare Worker, which immediately forwards them to the developer by email. The Worker stores nothing. Your IP address is used only to limit the number of reports per sender; it is not stored or included in the email. Reports are kept in the developer's mailbox and deleted no later than 12 months after receipt.

Support by email

If you write to support@solarstringcheck.com, your email address, message and any information or attachments you supply are processed to answer your request. The legal basis is Article 6(1)(b) GDPR for requests relating to a contract or steps before entering into one; otherwise it is Article 6(1)(f) GDPR, with the legitimate interest of answering your enquiry.

Messages are forwarded through Cloudflare Email Routing to a mailbox at Apple iCloud Mail. They are deleted once your enquiry has been resolved and no retention obligation applies.

This website

The website is hosted by Cloudflare. Cloudflare processes technically necessary data — IP address, time, requested address and browser identifier — to deliver the pages and prevent attacks. The legal basis is Article 6(1)(f) GDPR; the legitimate interest is the secure, reliable provision of this website.

This website uses no cookies or analytics and loads no fonts, scripts or images from third-party servers.

Recipients and international transfers

Cloudflare, Inc. (USA) provides website hosting, the Worker for error reports and email routing. Cloudflare is certified under the EU–US Data Privacy Framework. Transfers covered by that certification rely on the adequacy decision under Article 45 GDPR. See Cloudflare's privacy policy.

Apple provides iCloud Mail for the support mailbox. Apple also distributes the app through the App Store and TestFlight and processes the in-app purchase, acting as an independent controller for both. See Apple's privacy information.

Your rights

Subject to the applicable legal conditions, you have the right to access, rectification, erasure, restriction of processing and data portability. You may object to processing based on Article 6(1)(f) GDPR on grounds relating to your particular situation and withdraw consent at any time. Contact the controller above to exercise your rights.

You may also lodge a complaint with a data protection supervisory authority, in particular in the EU Member State of your habitual residence, place of work or the alleged infringement.