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Privacy Policy

Last updated: 5 November 2026

PV Freund is a free planning tool for photovoltaic systems. You can use it with no account, no sign-up and without telling us your name. This policy describes, in full, what data is involved.

The short version: we set no tracking cookies and run no Google Analytics. The figures you enter for planning (address, consumption, costs) are processed in memory and never written to a database. Google Maps loads only after you explicitly click to load it.

1. Controller

Raghul Babu
Am Gonsenheimer Spieß 1
55122 Mainz, Germany
Email: contact@pvfreund.com

We are not required to appoint a data protection officer (Art. 37 GDPR, § 38 BDSG); please send any request directly to the address above.

2. Hosting and server logs

The site runs on a server operated by Hetzner Online GmbH, Industriestr. 25, 91710 Gunzenhausen, Germany. The server itself is in Falkenstein, Germany. A data processing agreement under Art. 28 GDPR is in place with Hetzner. The data does not leave the EU.

Every page request is logged automatically by the web server:

  • your IP address
  • date and time of the request
  • the requested address (URL) and the HTTP status code
  • the volume of data transferred
  • browser and operating system identifier (user agent)

Purpose and legal basis: running the service, diagnosing faults and defending against attacks — legitimate interest under Art. 6(1)(f) GDPR. Retention: 7 days, then deleted automatically. These logs are not combined with any other source of data.

3. Audience measurement (self-hosted, no cookies)

We want to know which pages get read and where people abandon the planning wizard. We use no third-party analytics product for this — only our own counting on our own server. Per page view we store:

  • a random identifier for the visit (see section 8 — it applies only to the open browser tab and is discarded when you close it)
  • timestamp and the page visited
  • the country — derived from your IP address using a local database (MaxMind GeoLite2) on our own server. The IP address itself is not stored: it is discarded immediately after the country lookup and is never sent to a third party.
  • operating system, browser and device class (desktop / mobile / tablet)
  • the hostname of the referring site, if any (e.g. google.com) — never the full URL
  • which step of the wizard was reached, and whether a result PDF was downloaded

Visits from recognisable search-engine bots are discarded. No cross-device profile is built, there is no recognition across separate visits, and none of this is linked to the figures you enter.

Legal basis: legitimate interest in shaping the service around actual use, Art. 6(1)(f) GDPR. Retention: 90 days; a daily job deletes everything older. Objection: you may object to this measurement at any time under Art. 21 GDPR by email.

4. What you enter in the planning wizard

To calculate a system you enter data such as your address, roof surfaces, electricity consumption, electricity prices and, optionally, details about an electric car or heat pump.

These entries are not written to a database. They are processed in our server's memory at runtime in order to run the optimisation, and discarded when the calculation or your session ends. They are not linked to the measurement described in section 3, are not analysed, and are not passed to installers, brokers or any other third party — we do not sell leads.

Where the computation happens: the optimisation runs on the server for technical reasons (it is a linear optimisation model), not in your browser. The result PDF, by contrast, is generated in your browser.

Measuring roof pitch by phone via QR code

If you use the QR code to measure your roof pitch with a phone's orientation sensor, the measured angle is held briefly in the server's memory so it can be handed to your desktop browser, then deleted immediately. No device identifiers and no further sensor data are stored.

Legal basis for processing your entries: performing the calculation you requested, Art. 6(1)(b) and (f) GDPR.

5. Google Maps — only with your consent

To let you pick out your roof we show a satellite map from Google Maps. The service is provided by Google Ireland Limited (Gordon House, Barrow Street, Dublin 4, Ireland); data may be passed on to Google LLC in the USA.

The map is not loaded until you click "Load map". Until then no connection to Google is made. Once you click, your browser unavoidably discloses your IP address to Google, which may also set its own cookies — something we have no control over.

Address search (geocoding) and the loading of map tiles, by contrast, go through our own server: Google receives the address or the coordinates, but not your IP address.

Legal basis: your consent, Art. 6(1)(a) GDPR and § 25(1) TDDDG. Withdrawal: your consent applies only to the current browser tab. Close the tab or reload the page and you will be asked again — so you can withdraw it at any time with effect for the future simply by closing the tab. Data already transmitted to Google cannot be recalled by us. Further information: Google's privacy policy.

Without the map you cannot outline your roof; the rest of the wizard remains usable.

6. Solar irradiation data (PVGIS, European Commission)

To estimate yield we request irradiation data from PVGIS, a service of the European Commission's Joint Research Centre (JRC) in Ispra, Italy. Our server makes the request and sends only the coordinates of the location — no IP address and nothing about you personally. The processing takes place inside the EU. Legal basis: Art. 6(1)(b) and (f) GDPR.

7. Fonts

All fonts are served from our own server. There is no connection to Google Fonts or any other content delivery network, and your IP address is not disclosed to anyone for them.

8. Cookies and local storage

We use no advertising, tracking or marketing cookies and no Google Analytics. Only the following technically necessary entries are used:

NameTypePurposeDuration
session Cookie Random identifier so the server can match a running optimisation to your browser. Contains no personal data. HttpOnly, SameSite=Lax, HTTPS only. Session
pvf_sid sessionStorage Random identifier for the audience measurement (section 3). Until the tab is closed
pvf_maps_consent sessionStorage Remembers that you agreed to load the Google map, so you are not asked again at every step. Until the tab is closed
user-lang localStorage The language you selected. Until you clear your browser storage
pvf_solar_quota localStorage Counter of how many irradiation-service requests remain today, so the daily limit is not exceeded needlessly. Until the next day

These entries are required for the service you asked for, or they store a decision you made yourself; under § 25(2) TDDDG they therefore need no consent. You can clear your browser storage at any time in your browser settings.

9. Error logging

If a technical error occurs in the application we store the error message, the address (URL) affected, the time and how often it happened, so that it can be fixed. No IP addresses and none of your entered data are stored with it. Legal basis: Art. 6(1)(f) GDPR.

10. Disclosure to others

Disclosure happens only to the extent described above: to Hetzner as our processor for running the server, to Google if you consent to the map, and to PVGIS for irradiation data. Beyond that we disclose nothing, sell nothing, and do not forward your enquiry to installers.

11. Automated decisions

The system design is a calculated recommendation based on the values you entered. There is no automated decision with legal effect and no profiling within the meaning of Art. 22 GDPR.

12. Your rights

You have the right at any time to:

  • access the personal data we process about you (Art. 15 GDPR)
  • rectification of inaccurate data (Art. 16 GDPR)
  • erasure (Art. 17 GDPR)
  • restriction of processing (Art. 18 GDPR)
  • data portability (Art. 20 GDPR)
  • object to processing based on legitimate interests (Art. 21 GDPR)
  • withdraw a consent you have given, with effect for the future (Art. 7(3) GDPR)
A note on access requests: the measurement data described in section 3 deliberately contains no attribute that would let us connect it to you — no IP address, no persistent identifier. We therefore cannot provide access to that data or delete it selectively (Art. 11 GDPR). If you cannot help us identify it, objecting with effect for the future is the remedy that works.

You also have the right to lodge a complaint with a supervisory authority (Art. 77 GDPR). The authority responsible for us is:

Der Landesbeauftragte für den Datenschutz und die Informationsfreiheit Rheinland-Pfalz
Hintere Bleiche 34, 55116 Mainz, Germany
datenschutz.rlp.de

You may also complain to the supervisory authority of the EU member state where you live or work.

13. Changes to this policy

We update this policy when the technology or the law changes. The version published here is the one that applies; the date above shows when it was last changed. This English text is a translation for your convenience — in case of dispute the German version governs.

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