Privacy policy

What this covers. This policy describes how the SnapEnergyLab website works today, at the time and version shown above. It does not describe features that do not exist on the site. There is currently no advertising, no advertising technology and no personalised advertising on SnapEnergyLab; if that ever changes, this policy will be revised and re-versioned before such technology goes live.

The privacy model. There are three distinct kinds of information involved in using this site. The first is the data you type into a calculator, which for every tool except the solar output calculator is processed locally in your browser and is not transmitted anywhere. The second is the small, explicitly listed set of fields the solar output calculator sends to our server, and onward to two external public data services, when you press its calculate button. The third is the ordinary technical information that any browser sends when it requests a web page, which hosting infrastructure must process in order to deliver the page to you. Sections 2 and 6 describe each in turn.

No account. The site has no sign-up, no login and no user profile. Nothing you do here is linked to an identity that we hold.

What you may enter. Depending on the tool, you may enter figures such as electricity price per kWh, appliance wattage, hours or days of use, duty cycle, battery capacity and depth of discharge, inverter efficiency, solar array size, tilt and orientation, a city or postal code for solar output, vehicle battery size and efficiency, annual driving distance, heating demand and heat pump efficiency.

Where calculation happens. With the single exception described in 2.6, the calculation engines are JavaScript modules bundled into the page and executed by your own browser. When you change an input, the result is recalculated locally, no external pricing, weather, location or data API is called, and no form is submitted to a server.

Transmission. Apart from the fields listed in 2.6, your calculator values are not transmitted to SnapEnergyLab and are not shared with any third party. They are not encoded into the page URL or query string, so they do not appear in browser history shared through a link, in referrer headers, or in server request logs.

Retention. Values we never receive cannot be retained. Values you have typed disappear when you reload or leave the page, except for the small set of preferences described in section 3, which stay on your own device until you remove them. Retention for the solar lookup is stated in 2.6.

Distinguishing the flows. The statements above concern the content of your calculations. They do not mean that no network activity occurs at all: loading the page, its stylesheet, its fonts and its JavaScript are ordinary requests to our hosting infrastructure, described in section 6.

The solar output calculator lookup. The solar output calculator is the one tool that cannot run entirely in your browser, because it uses long-term solar-resource data for your location. Nothing is sent while you type; a request is made only when you press the calculate button. What is sent to our server is exactly five fields: the location text you typed, the system size in kWp, the panel tilt in degrees, the panel orientation, and the system-loss percentage. Our server then makes two onward requests. To the geocoding service (OpenStreetMap Nominatim) it sends only the location text — no system size, no electricity rate, no battery, vehicle or heating values, and nothing from any other calculator. To the solar-resource service (PVGIS, operated by the European Commission’s Joint Research Centre) it sends only the resulting latitude and longitude, system size, tilt, orientation angle and loss percentage. Both onward requests are made by our server, so those services receive our server’s IP address, not yours, and they receive no cookie, identifier or referrer from your browser. The site does not ask your browser for GPS or precise device location at any point. Results of both lookups are cached in the server’s memory for up to 90 days, keyed on the location text and the technical parameters only, so that repeated identical requests do not hit the external services again; this cache contains no identifier, no IP address and nothing that links a lookup to a visitor, and it is lost whenever the server instance restarts. We do not write these lookups to any database or log of our own. If the solar service is unavailable, the calculation falls back to a table bundled with the site and no further external request is made.

What is stored. The site can save a small set of display preferences in your browser’s local storage under a single key, snapenergylab.settings.v1. It holds your preferred electricity rate, your currency label, and whether you prefer imperial or metric units. No calculator scenario, result or identifier is stored.

Why. Only so you do not have to retype the same electricity rate on every page. The site works normally if this storage is unavailable or blocked; the preferences simply last for the current page session instead.

Where it lives. Local storage is a browser feature on your own device. The value is read and written by code running in your browser and is not sent to us. It is scoped to this site’s origin and is not readable by other websites.

How to remove it. Local storage is not a cookie, so clearing cookies alone may not remove it. Use your browser’s “clear site data” / “cookies and site data” option for this site, or delete the key above from your browser’s developer tools. Private or incognito windows discard it when the session ends.

Scroll positions. The site’s navigation library keeps your scroll position for pages you have visited in session storage, under the key tsr-scroll-restoration-v1_3, so returning to a page puts you back where you were. It holds scroll coordinates only, it is not sent anywhere, and your browser discards it when you close the tab.

Other browser storage. SnapEnergyLab does not use IndexedDB, does not store user data in the Cache Storage API, and uses no device-fingerprinting technique.

Current status. SnapEnergyLab does not set cookies of its own, and no cookie is required for any calculator or page to work. There is no cookie banner because there is nothing to consent to.

No advertising cookies. Since the site carries no advertising, no advertising or measurement cookie is set by us or by anyone else through our pages.

None in use. There is currently no analytics product, tag manager, tracking pixel, session recorder, heatmapping tool, A/B testing service or advertising SDK on this site. Page views are not measured by any such service.

If that changes. Introducing any measurement tool would be a material change: this policy would be updated and re-versioned to name the tool and describe what it processes.

What a page request involves. Pages are rendered and served by our hosting platform. As with any website, delivering a page means the hosting infrastructure receives and processes ordinary technical information: your IP address, the URL requested, the date and time, your browser’s user-agent string, and a referrer where your browser sends one.

Purpose. That information is inherent to delivering the page over the internet and is used by the infrastructure for serving content, reliability, and security and abuse prevention.

Runtime logging. Application code on this site does not write visitor request logs, and errors that occur during rendering may be logged as technical diagnostics by the hosting platform. Such diagnostics concern the failure itself, not your calculator inputs.

Retention limits we cannot state. Retention of infrastructure and network-level logs is determined by the hosting provider and its network layer, not by this application. We therefore do not state a specific retention period here, because we cannot verify one from the site’s own code.

No profiling. We do not combine technical request information with anything else to build a profile of you, and we do not attempt to identify individual visitors.

Content delivery. The hosting and content-delivery platform is the only third-party service involved in delivering the pages themselves. It necessarily processes the technical request information described in section 6 in order to serve pages to you.

Fonts and assets are self-hosted. Typefaces, stylesheets, scripts, icons and images are served from this site’s own domain. Loading a page therefore does not make a request to an external font service or asset CDN under someone else’s control.

No embedded content. There are no embedded videos, maps, social widgets, comment systems, chat widgets or iframes from other domains, so no other party observes your visit through embedded content.

Geocoding provider. To turn a place name into a coordinate, our server queries the OpenStreetMap Nominatim service, operated by the OpenStreetMap Foundation. It receives the location text you typed and our server’s IP address. It does not receive your IP address, any cookie, or any other calculator value. Geocoding results are used under the Open Database License and OpenStreetMap contributors are credited in the calculator’s source block.

Solar-resource provider. To estimate long-term production, our server queries PVGIS, a public service of the European Commission’s Joint Research Centre. It receives a latitude and longitude, the system size, the tilt, the orientation angle and the loss percentage, together with our server’s IP address. It does not receive your IP address, any cookie, the original text you typed, or any other calculator value. This service is queried only when you press the calculate button on the solar output calculator.

No data sales or sharing. Beyond the two narrowly scoped lookups above, we do not sell, rent or share personal information, and we have no advertising, data-broker or affiliate-tracking integration.

Global delivery. Websites are typically served from a distributed network of servers, so the technical request information in section 6 may be processed in a country other than your own — usually the location closest to you, but not necessarily.

Scope of the transfer. What may cross a border in this way is ordinary request and delivery information. Your calculator inputs are not part of it, with the single exception of the five fields listed in 2.6: those are sent to our server, and the narrowly scoped subsets described in 7.4 and 7.5 are forwarded to a geocoding service and to PVGIS, a service of the European Commission based in the European Union.

General audience. SnapEnergyLab is a general-audience reference and calculation service about household energy use. It is not directed at children and is not designed to collect personal information from anyone, including children.

No age determination. Because the site has no accounts and asks for no personal details, we have no way of knowing a visitor’s age and do not attempt to determine it.

Rights in principle. Depending on where you live, privacy law may give you rights to access, correct, delete, or restrict the processing of personal information about you, to object to certain processing, and to complain to a supervisory authority.

What this means in practice here. Those rights apply to personal information a service actually holds. SnapEnergyLab has no accounts, no user database and no profile of you. Figures typed into calculators are not sent to us and exist only on your device, so we cannot retrieve or delete them; you can remove them yourself as described in section 3. The solar lookup described in 2.6 does reach our server, but it is held only in a short-lived memory cache keyed on the parameters themselves, with no identifier attached, so there is no record that could be located, exported or deleted for an individual person.

Infrastructure records. Technical request information may be processed and retained by our hosting infrastructure. SnapEnergyLab does not maintain a separate visitor log or application database that allows us to look up those records by individual visitor.

Reasonable measures. The site is served over HTTPS, keeps its attack surface small by avoiding accounts, user data stores and third-party scripts, and processes calculator values only in your own browser.

No guarantee. No website or method of transmission over the internet can be guaranteed to be completely secure, and we do not claim otherwise.

Versioning. This policy carries a “last updated” date and a version number. Any change to how the site handles information — for example introducing analytics, a contact form, or advertising — will be reflected by revising this policy and increasing its version before the change goes live.

Related documents. How the calculations themselves work is documented separately in Methodology, Assumptions and Data sources. See also About, Terms and the Disclaimer.

Data controller. The data controller for SnapEnergyLab is Helge Andresen, operating the SnapEnergyLab website.

Contact. You can reach the operator by email at snapenergylab@gmail.com.