It will help but a residential frig uses a lot of energy. If I was mounting a panel I would buy 160 watts or so. It takes the same number of holes in the roof as a 100 w. You wire the panel to the controller and the controller to the batteries. Fuse or use re settable breakers so you can disconnect the panel before disconnecting the battery cables. Some controllers dont want solar power coming in while the battery is disconnected.
If you were sizing the solar bank to the battery you would want about 100 to 150 watts to each 100 ah of battery capacity. You have about 400 amp hours of battery. I started out with four 6 volts and 520 watts of panel. It worked well and we use a lot of power for furnace, led television etc. When I installed our residential frig I added 2 more batteries and 480 watts. So about 600 AH of battery and 1000 watts of solar.
If you want to add more panels later you may want to consider that now. It is very common to add more.
