Client in Corpus Christi has 6kW system installed in March. The production meter shows 4,280 kWh through October but the inverter monitoring system shows 4,890 kWh for the same period. That's a 14% difference. AEP Texas is only crediting based on their production meter reading. Is this normal variance or should I be concerned about meter accuracy?
Anyone else seeing weird solar production meter readings?
Vivian, that's a significant discrepancy. Most production meters are accurate within 1-2%. Could be a calibration issue or the meter might be failing. I'd request AEP Texas test the meter accuracy. They're required to maintain metering equipment within ANSI standards. If the meter is reading low, your client is losing money on every kWh of solar production.
Also check if there are any inverter clipping losses or system shading issues that might explain the difference. Sometimes the inverter monitoring shows DC production but the utility meter measures AC output after conversion losses. Still, 14% is too high even accounting for inverter efficiency. Warren's right - demand a meter test.