The idea
Estimate the solar potential of a specific rooftop instead of asking somebody to reason from a rough address or property description.
How it works
Users draw a rooftop polygon on satellite imagery. The app calculates area, fetches location-specific solar radiation data from NASA POWER, applies pvlib models, and estimates annual energy production and financial savings.
What it combines
- Mapbox satellite imagery and polygon drawing
- Geospatial area calculations with Turf.js
- NASA POWER irradiance data
- Solar modeling with
pvlib - A Python and Flask backend with cached calculations
The main calculation converts hourly irradiance into plane-of-array estimates, then applies panel efficiency, system-loss, and usable-roof assumptions. Results are cached by rounded coordinates and year so nearby repeat calculations do not keep hitting the upstream API.
Graceful fallback
If the upstream irradiance request or the full model fails, the app falls back to a simpler latitude-based estimate instead of leaving the user without a result.
Installer assistant
The prototype also passes available roof area, location, and savings context into an installer-recommendation assistant. It can query a small local knowledge base for region-aware recommendations and market information without asking the user to repeat details already captured by the map.
The project is specific to Pakistan, where a practical estimate in local currency is more useful than a generic solar calculator.