FAQ
Frequently asked questions
Short answers to the things people ask before they download. Still stuck? Get in touch.
Is the app free?
Yes. The core calculator is free and stays free: unlimited saved setups, cloud sync, the manual region picker, the optional NASA POWER refresh, and all twenty in-app articles. A one-time $6.99 lifetime Pro purchase is optional and only adds extra features — it never takes anything away from the free tier.
Do I need an account?
No. The app is local-first and works fully without signing in — your setups live on your device. An account is only needed if you want cloud sync across devices. Sign-in is via Apple, Google, or an email magic link; there is no password to remember.
What does "Pro" unlock?
Two things: PDF export (save a one-page summary of any setup to hand to an installer or print) and the side-by-side comparison view (stack two setups to see how a change affects cost and payback). Pro is a single $6.99 payment — not a subscription — and the unlock is for life on the store account that bought it.
Does the app work offline?
Yes. Everything except cloud sync and the optional NASA POWER refresh works with no connection at all. You can plan an entire system off-grid and sync later when you have signal.
How accurate is the sizing?
It is a solid planning estimate, not an engineering design. The maths uses standard off-grid sizing rules and your real inputs, so it gets you a well-scoped system and a realistic budget. For the final installation — wire gauges, fusing, mounting, code compliance — confirm the details with a qualified installer.
Where does the sun-hour data come from?
The app ships with a built-in table of peak sun-hours by region. If you want a sharper figure for your exact site, the optional NASA POWER refresh pulls solar-resource data for your latitude and longitude in a single network call. NASA POWER is a public dataset; no account or identifier is involved.
Will the calculator design my exact installation?
No. It sizes the system — panel wattage and count, battery capacity, inverter rating, cost and payback — so you know what to buy and roughly what it costs. It does not produce wiring diagrams, structural plans, or a permit-ready design. Treat the output as the starting point for a conversation with an installer.
Does the app use my location?
Not automatically. There is no GPS use and no location permission request. You pick your region manually. The only time coordinates are sent anywhere is if you tap the NASA POWER refresh yourself — and even then it is just a latitude/longitude, with no account or device identifier attached.
Is my data sold or shared?
No. Your data is never sold, and there is no advertising or behavioural analytics in the app. Data is only shared with the service providers needed to run the features you use — cloud sync storage, in-app purchase processing, and sign-in. The full breakdown is in the Privacy Policy.
How do I delete my account?
Open the app, go to the Profile tab, and tap Delete account — it removes your account and data immediately. If you can no longer access the app, you can request deletion by email. Full step-by-step instructions are on the Delete your account page.