You may have received a notice that your solar PV system had "Low Solar Production" or that your meter is "Possibly Wired Incorrectly." These notices are usually triggered by an issue that exists in your wiring configuration.
Because Eversource reads the meter only once a month, these issues can be difficut to diagnose. Therefore, when the utility suspects there may be a problem, it's based on a snapshot instead of realtime information.
Here's what you can instruct your solar installer to do to assist with issue resolution:
- Take note of which meter number is which.
For BTM solar systems, which represent most small-to-midsize customers, you will have two meters: a utility revenue net meter and a utility solar production meter. Based on the site's electrical setup, confirm that Eversource has identified these two meter numbers correctly on your bill, and that the identity of each meter (revenue vs. solar) is as expected.
- Confirm that there is no other load present behind the utility solar production meter beyond the draw of the inverter. Any loads that are present will cause the meter to represent lower production numbers than what your system is producing, as these loads will consume power before it reaches the meter.
- Check that each meter is wired according to the Eversource SMART Wiring Guidelines.
These guidelines require that the utility solar production meter socket is wired top side to the utility feed, and bottom side to the inverter. Special attention should be paid to this step, as this may be different than the way that installers intuitively wire this meter socket.
- Lastly, do you have a DC connected ESS battery? Sometimes, in DC connected battery systems (especially when wired to backup systems), the battery is not isolated to charge only from the PV system. When this is the case, the power draw that flows from the grid, through the meter, and to the battery reduces the apparent solar production, in some cases negating it entirely.
If it is determined that DC wiring is the root cause of the issue, the battery would need to be isolated by some means, such as an ATS, to prevent draw from the gird, which would in turn prevent low solar production from occurring.
Utility meter techs put the meters in the sockets and/or replace them when they are malfunctioning, but what happens with the wiring behind the meter is largely outside of Eversource's control.
At the same time, Eversource endeavors to make sure that customers are fairly and accurately compensated for solar production, even when limited to making suggestions to your solar installer.
Hopefully these suggestions help toward solving the root cause of your system's low solar production or wiring issue. Once a root cause is determined, Eversource, subject to management approval, will work with you to analyze available data and do a true-up upon correction.