The brief
Most solar and inverter decisions come down to five or six numbers: panel wattage, battery capacity, inverter rating, backup time, monthly cost and payback. Getting one wrong means paying for hardware you don't need, or running out of power during an outage. We built PowerPlanner for households and installers who deal with load shedding, rising tariffs and off-grid sites. It works out each of those numbers from simple inputs and shows how it got them.
What we built
You enter your system once: panels, battery capacity, voltage and chemistry, inverter and tariff. Every calculator reads from those details. Then you pick appliances from a built-in library or add your own, and the app gives you a full package: panel wattage and count, battery bank, inverter rating and a matching charge controller. It shows a "general" spec next to a "best" spec, so you can see what the upgrade gets you.
On top of that:
7-day solar forecast for your location: expected kWh, sun hours, irradiance by hour and battery charge, so you can plan heavy loads around the sun.
Electricity toolkit with per-appliance and whole-household costs on flat, slab or time-of-use tariffs. It also includes bill scanning, outage logging and a month-by-month savings tracker.
AI solar planner and energy advisor built on Gemini. The planner writes out the full specification with its reasoning. The advisor answers questions such as "can I add an air conditioner?" using your own numbers.
23 solar, inverter and battery calculators, from string sizing and voltage drop to battery lifecycle and net-metering ROI.
Plans, PDF export and scenario comparison, so an installer can size a system in front of a customer and hand over the plan on the spot.
Communities with moderation backed by Cloud Functions: automatic text and image screening, report handling and user bans.
How it's built
PowerPlanner is a single Flutter codebase for Android, iPhone and iPad. It is fully translated into eight languages, including right-to-left layouts for Urdu and Arabic. Firebase handles accounts (Google and Apple sign-in), sync, storage, Remote Config, Crashlytics and Analytics. Cloud Functions in TypeScript run moderation and account deletion. RevenueCat handles the Pro subscription and one-time purchase across both stores. AdMob pays for the free tier, OneSignal sends push notifications, and a home-screen widget shows your energy snapshot.
Business model
Every calculator works on the free tier, and you don't need an account to run a calculation. PowerPlanner Pro removes ads and lifts the limits on AI plans, advisor questions and PDF exports.
