Best answer by woz
There have been quite a few cases where meters have been incorrectly configured with solar installs, so it's entirely possible.
Have you been keeping records since the panels were installed?
You need to keep accurate records, but it doesn't happen ad-hoc, it's either been wrong from day 1 of the install or you've had a meter change.
HERE is an article, but a search brings up a lot of info
Hi all my electric usage is normally around 500 ish a month but in June I used 1300 ������ I do have solar panels would they be going through my meter??