I would like to measure the power entering my house, and subsequently each circuit but breaker. I have this working in principle in that I have a CT clamp, an ESP, and ESPHome all working with HA.
What I’m stuck on is how to reliably power the ESP. I know they’re too power hungry to be reliable enough for batteries, and given the proximity to the electric source it seems crazy not to power them from a CU feed.
I appreciate this is not strictly an HA question, but I would like to draw upon community wisdom and experience for a solution. For those of you that do measure total home power, how do you power your monitoring devices?
If you really “only” have a (plain) CT clamp all you actually have is a current meter and no energy meter (this is what people usually want because private individual are typically billed for energy and not current ).
Any (isolated) PSU should be actually fine. Probably most 5V USB (>1.2A) should be sufficent for that task.
It is indeed a current meter. So there is some calculation to get power. I’m using a static voltage value, but may get a reference voltage at some point; I know open energy monitor have something about this in their build docs.
I had an electrician over for their advice too, he reckoned installing a £16 RCB and run the site out the CU box and install something wall mounted in close proximity, which made sense.
Don’t forget to take the power factor into account. Depending on your load your “virtual” (calculated) power consumption might be far away from the truth (the one you get billed for )
On the other hand you might want to just upgrade your setup by using an Peacefair PZEM-004T V3 Energy Monitor — ESPHome which is (still) cheap to obtain and actually measures real power (current, voltage, power factor, frequency, …) out of the box.
).
) 