We paid for photovoltaic (PV) and a solar water heater on our house. We do save and now are only paying a nominal fee to remain connected to the grid.
I would be very cautious about any agreement allowing someone to install something on my roof for “free.” A company installed PV on the public library roof at a steep angle on elevated rails and the rails broke in high winds, leaving an expensive mess but fortunately not harming any people.
We asked friends and family members about their installation experiences and got several quotes and chose a company we felt would do a good job. We have no regrets and got a state and federal tax rebate for the solar and PV installations.
Of course we don’t have snow and have lots of sun so our issues are different from your climate. Due to the slope and orientation of our roof, the installation is at the back of the house and not visible from the streeet. It is also not blocked by neighbors.