Check your meter to see if it has a blinking LED. Most meters have a pulse LED which blinks X times per kWh consumes. Before smart meters where a thing I used t

Check your meter to see if it has a blinking LED. Most meters have a pulse LED which blinks X times per kWh consumes. Before smart meters where a thing I used to have a light sensitive transistor taped to my meter and just count the pulses. Even older models might have a digit replaced with a mirror on the last indicator dial. Which can also easily be read. Another one is magnetic pulse output, which can be read with a HAL sensor, but those are mostly found on water meters. Don't be satisfied with aggregated low resolution scraped metrics is what i'm saying. Per second real-time power measuring is the thing you want :).