1. Who is responsible
B-GREEN S.à r.l. is the controller for EnergyFlow account, project and service data. Our registered office is 11 Hannert de Kleppbeem, L-6995 Rameldange, Luxembourg; RCS B219547; VAT LU30609827. Email contact@energyflow.tech for privacy questions or requests. You can also write to our registered office.
This notice covers the website, signed-in application and simulation reports. The service is intended for adults. Please provide your own information and avoid entering personal details about other people.
2. Information we process
Account information includes your email address, account identifier and sign-in/session information. Project information includes the house description, location used to select weather, building geometry, equipment, occupancy assumptions, schedules and tariffs you enter. We store simulation results, saved scenarios, report text and PDF files against your account.
For purchases, we process order references, package, price, currency, tax and payment/refund status. Stripe collects payment details on its checkout page; EnergyFlow does not receive your full card number or security code. Support messages and technical records can contain contact details, IP addresses, request times and error information.
This release uses manual house entry. CPE, plan and quote uploads are not part of the released wizard. Do not put names, health information, passwords or payment-card details in project names or other text fields.
If you use the free heat pump simulator, what you enter (including a postal code or a fuel quantity) stays in your browser and is not sent to us. If you tell us your house is missing from it, we receive a rounded description of the house (country, floor area band, storeys, house type, construction period, heating type, and whether you gave a fuel quantity), any text you write and, if you choose, your email address. Please do not write personal details in the text field.
3. Why we use it
We use account, house and result information to provide the service you request: sign-in, saved projects, simulations, scenario comparisons, report preparation and support. The lawful basis is performance of our contract, or steps you ask us to take before entering a contract (GDPR Article 6(1)(b)). Required inputs are identified in the application; without them we may be unable to run a useful simulation.
We process necessary transaction and tax records to meet legal obligations (Article 6(1)(c)). We use proportionate security, access and error records to protect accounts, prevent abuse, investigate failures and establish or defend legal claims (Article 6(1)(f), our legitimate interests). You can object to processing based on legitimate interests, subject to the applicable legal conditions.
Accepting the terms is not consent to marketing or optional tracking. We do not sell your personal data or use your house inputs or documents to train AI models. We offer three optional uses. The first is advertising measurement. If you accept advertising cookies, Google Ads can count which ad clicks lead you to start a house, reach the run step, create an account, start a free preview or buy. The basis is your consent (Article 6(1)(a)), and you can refuse or withdraw it at any time without losing any part of the service. If you reject, or have not chosen, no advertising script from Google loads. The second is analytics. If you accept analytics cookies, we record how you use the website and the application: the pages you open, where you click, and a replay of the screen as you move through it. We use it to see where the site is hard to use and to fix it. Everything you type is hidden in the recording, and so are the figures for your house, your results and your account details. We do not record sign-in, account, checkout or payment pages. You stay anonymous: we do not link the recording to your name, email or account. The basis is your consent (Article 6(1)(a)), and you can refuse or withdraw it at any time without losing any part of the service. The third is the video player on our question pages, described in the next paragraph. Any further optional marketing or non-essential tracking will need its own information and, where required, consent.
The videos on our question pages load from YouTube only when you press play. Pressing play is your own request to watch that video, and the basis is your consent (Article 6(1)(a)). You give it for that video on that visit. We do not store that you pressed play, so the cookie banner does not ask about videos: pressing play is the choice. You can refuse by not pressing play, and you lose nothing by it, because the answer, the figures and a transcript of the video are on the page.
If you ask to be told when your house type is added, we keep your email address on the basis of your consent (Article 6(1)(a)). You give it by ticking a box and confirming the address, and you can withdraw it at any time with the link in every message. We keep the house description and your text, without your address, to see which houses are missing, on the basis of our legitimate interest in improving the simulator (Article 6(1)(f)). Your IP address is used only to limit abuse and is not stored. We send no newsletter and use the address for nothing else.
4. How the AI report summary works
The simulation produces the numerical results. AI helps explain selected results in plain language; it does not run the energy model, choose your equipment or make decisions with legal effects. The results page identifies an AI-generated explanation or a factual summary. Check the figures and discuss final building or equipment choices with a qualified professional.
For AI narration, our server sends OpenRouter selected, structured house and equipment characteristics, model assumptions, aggregated energy and cost figures, and temperature findings computed from your simulation. OpenRouter routes the request to a compatible provider serving an Anthropic model, such as Amazon Bedrock. The AI does not receive your name, email address, street address, postal code, coordinates, account/project identifiers, project name, uploaded documents or arbitrary text you entered. It receives no raw annual hourly file. Detailed house characteristics can still describe a distinctive property; removing direct identifiers does not guarantee irreversible anonymity.
AI requests may be processed outside the EEA, including in the United States. We require routes designated for no training and zero data retention for inference. These controls do not mean that all provider data is deleted immediately: transient memory/buffering or caching, billing and security metadata, and legally required records can be handled under the provider terms. We do not enable model web-search tools or plugins for report narration.
We save the validated summary with the run so the website and PDF agree. Returning to results or downloading the PDF reuses it. When AI is unavailable, fails validation or reaches our spending limit, a factual summary can be supplied instead. Operational records include the model/provider, generation time and usage/cost, without putting report request bodies in application logs.
5. Service providers and access
Vercel serves the website and application. Fly.io runs the API and simulation workers in Frankfurt. Neon provides the application database in the EU, Upstash Redis carries job queues, and Cloudflare R2 holds private project/result/report files in our EU storage configuration. These services receive the information needed to host, protect or operate their part of EnergyFlow; network and support operations may involve other locations.
Clerk handles account identity and sessions, including US-hosted processing. It does not receive house inputs, documents or simulation results in account metadata. Stripe handles checkout, payments, tax and refunds when purchasing is enabled. OpenRouter and the selected model-serving provider receive only the report input described above. Email services process sign-in and support correspondence; service emails use an email provider when enabled. A provider named here is not a promise that every planned feature is available.
Resend sends the emails EnergyFlow sends you: sign-in, invoice and simulator notification emails. It receives your email address and the message.
Only authorized personnel and service providers may access data for their assigned purpose. We may also disclose necessary information to authorities where legally required, or to establish or defend legal claims. Saved projects and reports are not published as a public database.
If you accept advertising cookies, Google Ireland Limited receives measurement data about ad clicks and what followed them. That is the ad click identifier from the address you arrived by and, at each of the steps named in section 3, a random reference of the house, preview or order. When you buy, it also receives the amount paid and the currency, so the purchase can be counted against the ad. Like any website request, it also receives your IP address and browser details. We send no name, email address, postal address or project data, and enhanced conversions are switched off. Without your acceptance, none of this is sent and no request goes to Google for it.
If you accept analytics cookies, PostHog Inc. processes the analytics described in section 3 for us, as our processor, on its EU cloud hosted in Frankfurt, Germany. It receives the pages you open with their addresses shortened (no query strings, no house or project identifiers), your clicks, the screen replay with typed text and your house figures hidden, a random visitor identifier, your browser and device type, and your approximate country. IP addresses are discarded and not stored. It receives no name, email, account identifier or ad click identifier, and the data is not used for advertising or shared with an advertising network. Without your acceptance, nothing is sent to PostHog.
If you press play on a video on a question page, the player loads from youtube-nocookie.com, a YouTube address run by Google. Google then receives your IP address, browser data and what you watch, and Google's privacy policy (policies.google.com/privacy) applies to that data. Before you press play, nothing is sent to YouTube or Google for the video: the picture you see is our own image, served from this website.
6. Processing outside the EEA
EU application storage does not mean every processing operation stays in the EU. Identity, payment, website/network services and the limited AI request can involve the US or other countries. For restricted transfers, the applicable provider arrangements use adequacy decisions for covered recipients or European Commission standard contractual clauses with relevant safeguards. Ask contact@energyflow.tech for information about the safeguards applicable to your data and a copy where available, with confidential commercial information removed.
OpenRouter's data-processing agreement is incorporated into its commercial terms and includes transfer clauses. Its zero-retention routing is a separate technical restriction, not a substitute for transfer safeguards. We review these boundaries when changing providers or the information sent to them.
Google may process advertising measurement data, and video playback data after you press play, in the United States. For those transfers we rely on Google's participation in the EU-U.S. Data Privacy Framework.
Resend stores email data in the United States, although our emails are sent from its EU region. For that transfer we rely on Resend's participation in the EU-U.S. Data Privacy Framework and on the EU Standard Contractual Clauses in its data processing agreement.
7. Retention and deletion
For a paid project whose order states no access end date, house data, saved runs, summaries and PDFs are kept while your account exists, until you ask us to delete them or we end the service. If we end the service, we give at least 3 months' notice by email and keep PDFs downloadable until that notice ends. For a paid project whose order states an access end date, they are retained until 24 calendar months after that paid access ends. A full refund that revokes access starts a 24-month period at revocation, for either kind of order. New simulations stop at access expiry; retained PDFs remain available during the retention period. Free accounts with no purchase retain saved house/run data for 12 months of inactivity. You may request earlier deletion by email. These are retention policies; expiry cleanup may be carried out by an operator while automated scheduling is being completed.
Account deletion removes the associated house and run data and private report files, subject to any applicable legal exception. A request acknowledgment is not confirmation that deletion has finished. We restrict access while deletion is pending, handle failed cleanup attempts and confirm completion separately. Backup copies can remain for the provider's limited backup cycle; they are not used as an active archive, and deletion must be reapplied if a backup is restored.
We retain necessary accounting records separately for 10 years after the close of the relevant financial year where Luxembourg accounting law requires it. Deleting a house or account does not erase legally required invoices and payment records. Support and security records are kept only as long as needed to resolve the request, investigate an incident or establish/defend a claim within the applicable period; unrelated house details are not required for accounting retention.
An email address left for the simulator notification is deleted 7 days after the request if you do not confirm it, after the one notification once your house type is added, and in any case 12 months after the request. The request itself, the house description and your text, is deleted 12 months after you send it.
Analytics events and screen replays are kept for at most 90 days, then deleted.
9. Your rights and complaints
Subject to the GDPR's conditions, you can request access, correction, erasure, restriction and portability of your personal data, and object to processing based on legitimate interests. If processing relies on consent, you can withdraw it without affecting the lawfulness of earlier processing. Contact contact@energyflow.tech from your account email; we may need proportionate information to verify that the request is yours.
We normally respond within one month of receiving a request. If the law permits an extension for a complex or numerous request, we will explain it within that first month. Our ordinary support reply target does not change these statutory deadlines.
You can lodge a complaint with Luxembourg's Commission nationale pour la protection des données (CNPD), or the supervisory authority in the EEA country where you live or work or where an alleged infringement occurred. See cnpd.public.lu for the CNPD complaint procedure. You do not have to contact us first.
10. Changes to this notice
This English notice applies from 3 November 2026, when the free heat pump simulator was added, to the described service processing. We retain a dated copy and publish changes here. We will give additional information where a new purpose, provider or data flow requires it.
Permanent link to this notice. Contact us or visit the CNPD rights and complaints page.