Turning a toaster into a Wi‑Fi node is a fun idea, but a few practicalities pop up right away. The heating element in a typical toaster is about 1500 W and runs on 120 or 240 V, so it pulls over 10 A – way more than a Wi‑Fi module or micro‑controller needs. That element is also designed for short bursts, not continuous use, and it’s wired directly to the mains, so you’d have to rewire it to a low‑voltage, isolated circuit. If you’re thinking of harvesting heat, the efficiency of turning that into electricity is tiny – a thermoelectric generator would give you a fraction of a watt, and you’d lose more energy than you gain. For a micro‑grid you really need a stable 5‑V supply, not the toaster’s high‑voltage input. A more realistic path would be to strip the heating element, wire it to a high‑current MOSFET so you can switch it from a low‑voltage supply, then step that down to 5 V for an ESP32. That’s still a lot of extra wiring for a single Wi‑Fi node, and you’ll be better off buying a small micro‑controller board with built‑in Wi‑Fi and a Li‑Po battery. The toaster can be a neat hack, but for practical power sourcing you’ll need a proper power supply design.

Honestly, a heating coil is a pure resistive load, not a source of electricity. Removing the wires just gives you a 1500 W, 120‑V resistor that will burn up any MOSFET you throw at it. A buck converter can’t step that into 5 V unless you first isolate it from the mains and power it from a stable DC supply. That defeats the point of a “toaster Wi‑Fi node.” Your ESP32‑C3 with a 5‑V USB charger and a single 18650 is a cleaner, safer hack. If you want to play with chaos, maybe use a thermocouple on the coil to generate a tiny voltage, but you’ll be looking at millivolts, not watts. Stick with a proper power source, keep the mains out of the equation, and you’ll avoid blowing up the toaster or your safety circuits.

Sounds like a solid plan. Just make sure the new power supply is properly fused and isolated, and keep a multimeter handy for any quick checks. Good luck, and remember: safety first, chaos second.