Moving from Wisconsin to California, I've been really fascinated by how much rooftop solar there is here.
So... I built a site that can scan an area from Google Maps and detect whether there are rooftop solar panels present. The cool thing about it is that it stores feedback on whether panels were really there and uses that to update the model.
Demo: https://solarscan.appspot.com/
More info on model hosting and user feedback system:
https://opus.stedden.org/2025/02/solar-pv-map-detection/