Inverter failure

[GHartley]

I purchased an 8000 kW system about a year and a half ago and my electric consumption went from 9000 kWh per year to 14,000 kWh per year. I finally called my solar installer to ask if they had any insight into how this would happen. The service department told me that two of my inverters had failed. They were waiting for replacement parts and would contact me soon to have them installed. After this conversation my electric consumption dropped by about a third. Is it possible that my failed inverters were drawing electricity from the grid? Is it possible that sun power could have done something remotely to stop the energy drain. I

[ButchDeal]

I purchased an 8000 kW system about a year and a half ago and my electric consumption went from 9000 kWh per year to 14,000 kWh per year. I finally called my solar installer to ask if they had any insight into how this would happen. The service department told me that two of my inverters had failed. They were waiting for replacement parts and would contact me soon to have them installed. After this conversation my electric consumption dropped by about a third. Is it possible that my failed inverters were drawing electricity from the grid? Is it possible that sun power could have done something remotely to stop the energy drain. I

We would need more information but pretty damn sure you have an 8kw system not an 8MW system from your description.

what model inverters do you have?

also your consumotion did not change, but your grid usage would.
Are your sure that you have net metering?

[inetdog]

I purchased an 8000 kW system about a year and a half ago and my electric consumption went from 9000 kWh per year to 14,000 kWh per year. I finally called my solar installer to ask if they had any insight into how this would happen. The service department told me that two of my inverters had failed. They were waiting for replacement parts and would contact me soon to have them installed. After this conversation my electric consumption dropped by about a third. Is it possible that my failed inverters were drawing electricity from the grid? Is it possible that sun power could have done something remotely to stop the energy drain. I

One distinct possibility is that when you commissioned your PV system your utility failed to replace your existing meter with a bi-directional meter suitable for grid interactive inverters.
To prevent power theft by reversing the meter in its socket most utility meters have been designed to count usage upward regardless of which direction the power is flowing. That could mean that for all that time you have been billed by your POCO for all the electricity you put back into the grid as well as for what you are taking from the grid.
Have your utility check for that ASAP! (They did sign off on your PV installation, didn't they?) What SunPower did was stop your system from producing so much extra energy that you were getting billed for.
If your consumption went from 9,000 to 14,000 on turning your PV on, it probably should have dropped from 9,000 to 4,000 instead. You are due a substantial refund from whoever was at fault, POCO or your installer.

[azdave]

If your consumption went from 9,000 to 14,000 on turning your PV on, it probably should have dropped from 9,000 to 4,000 instead.

Faulty inverters may explain some of that but, like some people here have discovered after a new install, other family members think the electricity is now nearly free and they begin consuming it like never before.

[GHartley]

Definitely have a working net meter. I note that it decreases every day and increases at night. Only two people in the house. No kids. No changes in appliances. We are pretty frugal and hoped that solar would cover our usage. Can anyone recommend a good consumption monitor?

[bcroe]

An event here was like that. The well developed an internal leak, pressure dropped some and the pump
ran continuously. Since it happened in a heavy electric heating season, it was not at first obvious.

You need to get more numbers on just what is happening. There are a lot of devices available to monitor
KWH energy flow. Bruce Roe