SPE is a newish (2018?? standardized) 2-wire power+data twisted pair for 1km wire lengths at 10 Mbit. It's expensive to play with right now. But the specs are

SPE is a newish (2018?? standardized) 2-wire power+data twisted pair for 1km wire lengths at 10 Mbit. It's expensive to play with right now. But the specs are cool. 1km lengths is nuts, and a PoE-like feature on a singular twisted pair minimizes the wiring requirements on industrial scale plants. Hobbyists probably should stick to PoE honestly. But playing with new protocols is still fun.