How do grid tied inverters interrupt grid voltage
Electrons are fungible &mdash; you can't tell the difference between one electron and another. Therefore, no actual switching is required &mdash; your power meter simply measures the net power consumption of your house, which is the difference between what your loads require and what the solar array is providing.

In some jurisdictions, if that net value becomes negative &mdash; in other words, you're generating more power than you need &mdash; the meter does measure the power that you're feeding into the grid separately, because the rate at which you sell power to the grid is not the same rate at which you purchase it.