In the same vein, many smart meters coming onto the market have a P1 port [0], which is an open interface to read metering and pricing data. It's designed to b

In the same vein, many smart meters coming onto the market have a P1 port [0], which is an open interface to read metering and pricing data. It's designed to be safely used as an interface by third party hardware, and physically operates over a RJ12 connector (phone jack) with 5V. There are even DIY projects, powered by ESP boards, to interface with it - and electricity companies are ok with that, as it's designed for this use case. [0] https://www.cdem.be/13_technical/ https://www.cdem.be/13_technical/