Looking to monitor power consumption so I can split electric bill with roommates So I live in a house with 3 roommates and since getting my model 3 in trying to figure out how best to compensate for my at home charging so I can pay for my cars part.

 Right now we split the bill evenly but I also now want to deduct my M3 electric costs as well from my roommates part of the bill.

I know the trip meter in the car has a kwh reading on it but I'm not sure how accurate that is with the energy loses. 

My charger is hooked up to a nema 6-50 plug in the basement.

Is there like a clamp or plug I could get that can handle the high current and give me a proper readout?

Thanks in advance!