The time has come for me to run power to my detached garage. A little bit of background - I am well versed in all aspects of home improvement, am fairly comfortable and have done my fair share of electrical work.
The garage is approximately 80ft from the house, and I have already dug and ran 2" conduit from the house to the garage in a straight line. The conduits point of entry into the house is on the corner opposite the houses service main panel (approximately 30ft away in a straight line) so part of the run would be through the drop ceiling of the basement. The total run would be approximately 120ft.
The house has a 200A main panel with an existing sub-panel coming off of it on a 50A 2 pole breaker - the sub-panel has a couple unused breaker slots available.
The garage is a "1.5" car garage. I would like to have enough amperage in the garage to run inside/outside lights (LED), a 1 head mini split system, garage door opener, standard 120v outlets on all the walls and I would like to have the option of adding a 220v outlet for an electric car charger/welder/some other heavy duty equipment if the need arises at some point in the future.
My plan is to run the wires, install the garage sub-panel, lights, outlets, etc and then have a local electrician do the final hook up to the main panel.
So now on to my questions...
Panel sizing: how many amps and spaces would you recommend, based on my needs outline above?
Aluminum vs copper: It seems like the general consensus is that there is significant cost savings from going with aluminum vs copper and is common for this kind of run.
Gauge & individual conductors vs Romex: It seems like most of the time, individual conductors are used in these situations - however I'm having trouble figuring the exact gauge of each wire. I have also seen a few people recommend using 2-2-2-4 Mobile Home Feeder cable. Also, from my understanding the run inside the house (from the conduit entrance point to the panel) would need to be in conduit if using individual conductors or can transition to another type of cable to run without conduit (I would prefer to not have to run conduit inside the house). Specific guidance would be super helpful here!
Grounding rod - it seems that it's recommended that at least 1 grounding rod be installed by the garage panel. I did also read somewhere that 2 rods is recommended. Alternatively, I have seen recommendations to just connect to the houses ground. What is the right course of action here? Is a hammer drill the best way to drive a grounding rod into very rocky clay soil?
Any and all guidance is highly appreciated.