My power company has very consistently reported 45kWh ± 5% per month higher consumption than my grid-tied Enphase system data over the first 6 months of my installation. Why would that be?
Is my power company, my smart meter or my solar PV system likely at fault?
I have 3-phase power and a smart meter. The 3 Enphase consumption CTs are installed in my main switchboard.
Could this be a resistive loss somewhere? If I’m calculating it right that would be about 60 Watts continuous draw.
Could it have something to do with power-factor (reactive load)? I don't have any heating, cooling or fluorescent lights in the house if that helps.
- My utility typically reports between 170 kWh/month (summer) and 330 kWh/month (winter) consumption and my solar system reports almost exactly 45 kWh/month less than that.
- There doesn't seem to be any correlation between this discrepancy and my production, consumption, imports or exports.
- My export numbers are very accurate.
- I have 3 phase both to support my 90cm induction cooker and for future proofing (future EV, etc).
- Not sure how I would put together a system diagram, but happy to pop the switchboard cover and share photos if that helps.
- My biggest single load is a small resistive single-phase hot water system which uses between 3.5 kWh/day (summer) and 5.5 kWh/day (winter) to heat. This is on a timer in the middle of the day.
- I was told that for metering purposes my imports/exports are boiled down to a single number across all 3 phases (unsubstantiated though).