Uber Solar Water Heater, Complete High Pressure System 18 EVT 100 Litres Close Coupled Thermosiphon. Collector is facing South West at 7 deg slope to horz, with a slight tilt towards North West to aid the thermosiphon.
Solar water heating system. Direct coupled separate vac tube array connected to a well insulted 150 litre Geyser using natural thermo-siphon for heat transfer. Electric element backup is connected with timer set on from 18h00 to 20h00.
ESP-WROOM-32 on a selfmade PCB-layout with an BME280 sensor. Powered by an 1W 6V Solarcell and a 2000mAh LiPo Battery.
The device is up for 1300ms and sleeps 10 minutes.
The current while sleeping is about 11µA and at uptime about 100mA.