using single phase inverters in a three phase building

Welcome to the forum Daveund,

I would suggest you start your own thread/discussion if you need to continue to go into detail about your system (avoids confusion with Q&A from original poster).

I guess you are in the USA, possibly in California?

To answer your question--I am pretty sure that the meter will properly record your energy consumed and produced....

However, there are other issues that you may come across.

First is that some (few, many, all?) may have a maximum 3 phase imbalance of 10 kWatts when feeding power back to the utility.

Second is that you may find that you need to insure that if there is a phase drop, that the multiple inverters are safely shutdown (either external relays, or with shutdown control logic for the separate inverters).

Third is that whatever the "meter reads", will depends on how the utility has programmed them (many/most meters in California seem to be "smart" meters these days). While the meter can read power draw and backfeed, the utility may program something called "revenue guard). This is to prevent people feeding energy back into the grid (via solar, etc.) and to prevent people taking a meter and "installing it upside down" (i.e., installed correctly for 3 weeks of month, upside down for 1 week a month to run meter backwards and steal energy).

The utility will probably install a new meter anyway coded to your rate plan (time of day, logging energy sold to utility with a different "register" than power purchased from utility--All depends on rate plans).

In California, they are in the process of overhauling GT solar rate plans.... As I understand, California would basically let GT Solar run the meter backwards when feeding GT solar to grid, and run the meter forwards when buying from grid... Basically buying/selling energy at a single "retail" value.

The new rate plans (to be implimented in a few months?) will only buy power from GT solar at something like $0.085 per kWattHour). And selling to customers can be as high as $0.40 to $0.50 during peak times).

As to how much money you can safe with GT Solar--You may need to talk with an engineer or other expert about how the new rate plans would affect...

And if this is a commercial account (farm, industrial, etc.)--GT solar was already a fairly confusing mess regarding billing (in times past, roughly 50% of bill was $/kWH, and other 50% of bill was "15 minute per month peak energy flow"--Which with GT solar could dramatically affect your billing... I.e., you consume energy 24 hours per day, and solar only feeds back ~6 hours per day--For 100% energy offset, your GT solar would be something like 4x the average pre-solar 15 minute peak. And this could cause the electric bill to be higher with GT solar vs without GT solar).

Again, some of these issues where in times past (more than a decade ago)... But with billing/rate plans continuing to change--You need to make sure your system energy usage/generation actually is financially viable and you don't get blindsided with your actual billing.

-Bill