tl;dr I’ve been monitoring my power usage for a while now, and the method I’ve been using is having similar issues to how a manufacturer in F1 allegedly cheated with their fuel pump system.
history I’ve created a prometheus p1 exporter that listens to a p1 port and exports the metrics to prometheus. The P1 protocol works over a serial connection and sends a packet every second. These messages are then parsed and the relevant metrics are exposed to prometheus.