I think it's not enough to simply calculate based on electricity use, generation, import and export in your home. PV setups contain considerable amounts of grey energy in the panels and especially the batteries, and on top of that most of the tech is made in China nowadays which has very carbon-intensive electricity.
Some reading on that (note that the articles are from 2015, but AFAIK the issue hasn't fundamentally changed):
https://solar.lowtechmagazine.com/2015/04/how-sustainable-is-pv-solar-power/
https://solar.lowtechmagazine.com/2015/05/how-sustainable-is-stored-sunlight/