Last updated: March 20, 2026
Solar Stack ("we", "our", "us") respects your privacy. This policy explains what data we collect, how we use it, and your rights regarding your personal information.
We collect information you provide when using our service: your Google or Telegram account profile (name and email) when you sign in, solar equipment specifications you upload or enter manually, and calculation parameters and results you save. We also collect: feedback form submissions (email, name, category, and message), equipment issue reports, datasheet PDF uploads for equipment extraction, and your locale preference (saved automatically when you visit the site). If you use the optional location feature on the calculator, your chosen coordinates (latitude/longitude via an OpenStreetMap map) are stored with your calculation — we do not use automatic geolocation. We automatically collect basic usage data such as browser type, device type, and pages visited through Vercel Analytics. IP addresses are read from request headers solely for rate limiting and are held in server memory only — they are not stored in any database or log. When duplicate Telegram accounts are detected, they may be merged automatically to maintain a single user profile.
We use your data to provide the compatibility calculator service, save your equipment and calculation history, improve the accuracy of our extraction algorithms, and maintain service reliability. Feedback submissions and equipment reports are forwarded to our administrators via email (Fastmail) and Telegram for review. When you submit equipment for approval, you will receive email notifications about the status of your submission (approved or rejected). IP addresses are used for in-memory rate limiting to prevent abuse — they are not persisted or shared. We do not sell your personal data to third parties.
We use essential cookies for authentication (session management). Vercel Analytics collects anonymous, aggregated performance data — no personal information is tracked. We do not use advertising cookies or third-party tracking pixels.
We use the following third-party services: Neon (database hosting), Vercel (application hosting, analytics, and blob storage for uploaded PDF files), Anthropic Claude API (AI-powered datasheet extraction — uploaded PDF content may be sent to Anthropic for processing), Google/Telegram (authentication), Fastmail JMAP API (transactional email notifications to users and administrators), OpenStreetMap (map tiles loaded in your browser for the optional location feature — subject to OpenStreetMap's privacy policy), and Telegram Bot API (admin notifications and optional account linking). Each service has its own privacy policy governing their handling of data.
We implement industry-standard security measures to protect your data, including encrypted connections (HTTPS), secure authentication via OAuth providers, and database access controls. However, no method of electronic transmission or storage is 100% secure.
We retain your data for the following periods: calculation history and saved equipment are retained for as long as your account exists. Feedback submissions are retained until resolved and may be kept in internal records for service improvement. Datasheet PDFs uploaded for equipment extraction are retained during the review process and may be deleted after processing. Rate-limiting data (IP addresses) is held in server memory only and is cleared when the server restarts — it is never written to a database. Account data is deleted upon request — contact us using the information below to request full account deletion.
You have the right to access, correct, or delete your personal data at any time. You can delete your uploaded equipment and calculation history through the application interface. You also have the right to data portability (request an export of your data), the right to restrict processing, and the right to withdraw consent for optional cookies at any time via the cookie consent banner. If you believe your data rights have been violated, you have the right to lodge a complaint with a supervisory authority in your jurisdiction (GDPR Article 77). To request complete account deletion or a data export, contact us using the information below.
We may update this privacy policy from time to time. We will notify users of significant changes by updating the "Last updated" date at the top of this page. Continued use of the service after changes constitutes acceptance of the updated policy.
If you have questions about this privacy policy or your personal data, contact us at privacy@solar-stack.com.