A solar-powered Raspberry Pi on our roof updates this page every 10 minutes with the current power output and battery level. You can read more about it at https://solar.dri.es/ (mirror).
Hourly solar panel voltage
Each row is a day and each square is an hour. A green square means there is plenty of sunlight, allowing the battery to recharge quickly. A red square indicates insufficient sunlight such as at night and on very cloudy days. As a result, the battery isn't charging, and the Raspberry Pi is gradually depleting it.
Hourly battery charge
A green square means the battery is well-charged and can power the Raspberry Pi for several days. A red square indicates the battery charge is low and requires solar charging soon.
Daily battery levels
This graph displays the battery's highest (green solid line) and lowest (red dotted line) charge levels each day. It helps track trends and assess the risk of the Raspberry Pi shutting down due to insufficient sunlight or extreme temperatures, which prevent the battery from charging.