Off-grid solar setup
I got my hands on a 600W 12V inverter so I decided to experiment with generating my own electricity. The inverter converts 12V DC power into 100V AC electricity which can be used for household appliances. Here, the 12V DC power is supplied by a 45Ah lead-acid battery, which would allow the inverter to run at full power for slighlty short of an hour.
The battery is charged by a 30W solar panel, through a 10A solar charge controller. Thus, with full sunlight, the battery would theoretically be charged in about 18 hours. I don't intend to use the inverter on a daily basis so the slow rate of charge isn't so much of a limitation. If needed, I could still add another solar panel in parallel in order to boost the chargin current.
To keep an eye on the battery's charge level, I made a simple protoboard featuring an ESP32 dev board that reads the battery voltage through a voltage divider. This measurement can be seen in real time through a webpage served by the ESP32. On top of that, the ESP32 also broadcast the measurement periodically via MQTT.
In addition to the power inverter, I installed a 5V DC-DC converter so as to charge devices like smartphones through USB.