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 four 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. The fourth exists only if you choose it: aggregate usage measurement through Google Analytics 4, which is loaded solely after you accept Analytics. Sections 2, 4, 5 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 the 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. A second key, snapenergylab.consent.v1, records your Analytics consent decision and is described in 4.2.

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.

No cookies before consent. SnapEnergyLab sets no cookies of its own, and no cookie is required for any calculator, guide or page to work. The only cookies that can ever appear on this site are the Google Analytics 4 cookies listed in 4.3, and they are created only after you explicitly accept Analytics in the consent banner. If you have not decided, or you rejected Analytics, no Analytics cookie exists and no Google tag is loaded.

The consent record. Your decision itself is remembered in your browser’s local storage under snapenergylab.consent.v1. It stores whether Analytics was granted or denied and the timestamp of the decision. It is strictly necessary for honouring your choice, contains no identifier, is never sent to us or to Google, and stays on your device until you clear site data or change the decision. It is local storage, not a cookie, so it has no expiry date of its own.

Analytics cookies set after consent. Once you accept Analytics, Google Analytics 4 sets two first-party cookies on this domain:

• _ga — set by Google Analytics; used to distinguish one browser or device from another for aggregate statistics. Provider: Google. Google documents a typical lifetime measured in years, and the exact duration is controlled by Google’s current configuration rather than by us, so we do not promise a fixed deletion date.
• _ga_6VV8F5LCVC — set by Google Analytics for this site’s GA4 property (measurement ID G-6VV8F5LCVC); used to persist session state. Provider: Google. Same duration caveat as above.

These are the only Analytics cookies observed on this site. Cookie lifetime is a separate matter from how long Google retains event data in the Analytics property, which is stated in 5.7.

No advertising cookies. The site carries no advertising, and this consent grants Analytics only. Advertising signals are held at denied at all times, as described in 5.3. No advertising, remarketing or personalisation cookie is set by us or by anyone else through our pages.

Changing or withdrawing your choice. “Cookie settings” in the footer of every page reopens the consent controls, so you can accept Analytics later or withdraw it. On withdrawal the site stops Analytics measurement for subsequent activity and attempts to delete the GA cookies it can reach from this domain. Cookies your browser holds for other reasons, or which are not accessible to page scripts, must be cleared through your browser’s own site-data controls.

What is used, and only after consent. SnapEnergyLab uses Google Analytics 4, measurement ID G-6VV8F5LCVC, provided by Google. The implementation follows Google’s Basic Consent Mode: the Google tag is not loaded, no request is sent to Google and no Analytics cookie is written until you explicitly accept Analytics. Rejecting Analytics keeps it disabled entirely.

Purpose. Aggregate measurement of website usage and performance — which pages and calculators are used, how visitors move between them, and whether pages work — so the site can be improved. It is not used to make decisions about individuals.

Advertising signals stay denied. This consent grants analytics storage only. The advertising signals ad_storage, ad_user_data and ad_personalization are set to denied and are never granted by accepting Analytics on this site. Google Signals data collection is switched off in the Analytics property, so no cross-device or advertising-personalisation signal is collected. There is no advertising, remarketing, audience export or personalisation feature in use.

What GA4 may process after consent. Once loaded, Google Analytics 4 may process categories of information such as: page views and interactions with pages on this site; the page address, title and referrer; browser and device information such as user-agent, language, screen and platform details; session information such as session start, engagement and the cookie-based identifiers described in 4.3; and approximate geographic information derived by Google from the IP address of the request.

What we never send to Analytics. SnapEnergyLab does not send names, email addresses, account identifiers or any other directly identifying information to Google Analytics, and does not send your calculator inputs. No such field is configured as an event parameter or user property. The site has no accounts, so it holds no identity to attach to a measurement in the first place.

Google as service provider. Google acts as the Analytics service provider. After you consent, the measurement data described above is transmitted to Google and processed on Google’s infrastructure under Google’s own terms and privacy documentation, which may involve processing outside your country. We do not control Google’s retention of that data beyond the settings the Analytics product exposes.

Retention of Analytics data. The GA4 property is configured to retain event-level data for 14 months, after which Google deletes it according to its own deletion process; aggregated reporting totals may persist beyond that. This is a property setting about data held by Google and is not the same thing as the lifetime of the cookies in 4.3.

Refusing costs you nothing. Every calculator, guide and page on this site works identically whether you accept, reject or never answer the Analytics question. Nothing is gated behind consent, and withdrawing consent later does not remove any functionality.

Nothing else is in use. There is no tag manager, tracking pixel, session recorder, heat-mapping tool, A/B testing service or advertising SDK on this site. Introducing one would be a material change: this policy would be updated and re-versioned to name it before it went live.

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. The single exception is the Google Analytics tag, which is requested from Google only after you accept Analytics.

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.

Analytics provider. If, and only if, you accept Analytics, Google is a further third party: your browser loads the Google tag and sends the measurement data described in section 5 to Google, which therefore also receives your IP address and the technical request information inherent in that connection. This does not happen before consent, and it stops for subsequent activity if you withdraw consent.

No data sales or sharing. Beyond the lookups and the consented Analytics measurement described 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.

Analytics transfers. If you accept Analytics, measurement data is transmitted to Google and may be processed by Google in countries other than your own, including the United States, under Google’s own transfer safeguards. Declining or withdrawing Analytics consent prevents that transfer.

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.

Analytics. The most direct control over Analytics is consent itself: you can refuse it, or withdraw it later through “Cookie settings” in the footer, and clear the cookies through your browser. Analytics data held by Google is aggregate measurement that we cannot query by person, because no identifying information is sent to it; requests that require identifying an individual record therefore cannot be satisfied from it.

Reasonable measures. The site is served over HTTPS, keeps its attack surface small by avoiding accounts and user data stores and by loading no third-party script other than the consented Analytics tag, 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 the operator of this independent website. SnapEnergyLab provides free energy calculators, tools, and informational resources. For questions about the website, contact snapenergylab@gmail.com.

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