Solar + Thermoelectric Energy Harvester
Two ambient energy sources, one battery-free IoT power supply.
What it does & why.
A hybrid harvester that combines a photovoltaic panel with a thermoelectric generator (TEG) to keep a low-power IoT node running without a wall socket or frequent battery swaps.
An MPPT front-end tracks the peak power point of both sources independently, then a supercapacitor + Li-Po buffer smooths the intermittent supply so the ESP32 node stays awake through cloudy days and cool nights.
Signal, energy & data flow.
Dual energy capture
A small PV panel and a Peltier-based TEG each feed their own boost converter.
MPPT tracking
A lightweight perturb-and-observe MPPT loop nudges each converter to its peak power point.
Buffered storage
Harvested energy tops up a supercapacitor bank, which trickle-charges a protected Li-Po cell.
Duty-cycled reporting
The ESP32 wakes on a timer, reads sensors, sends a LoRa packet, then deep-sleeps.
Dual-source harvesting
PV + thermoelectric feed a shared power bus.
MPPT efficiency
Custom perturb-and-observe loop for both sources.
Off-grid ready
Runs indefinitely without external power.
Deep-sleep firmware
Sub-1mA idle draw between reports.