Totally hear you on the CA vs MA weather swings (I've lived in both!). We actually see this as a key advantage for us. Sites we've visited in central CA have significant water distribution logistics, frequent shade breaks, and still have high heat exhaustion rates. Sites we've visited in northern climates report about 50% speed reduction in work due to gloves/cold, and will send workers home if the temperatures drop far enough. Our robots can handle both climates without an impact on installation rates (or any of the associated health risks for workers!).
It might be too early to tell.
Those telehandlers and skidsteers are almost always rentals, so they get called off and picked up at the site. Moving heavy machinery is much more difficult than moving people, and all of your equipment is unique so it’s glued to that job site until it’s complete. Owning your own equipment presents its own set of challenges - you have to store it when it isn’t being utilized, keep excess capacity in case it becomes unavailable, fix/repair on your own, etc. All of the costs in the current installer model, while perhaps higher, are tightly coupled with the cash flows from the job portfolio. This might decouple the cash going out from the cash coming in, to say nothing of the fixed costs of having having hardware/software engineers on staff.
I really want this to succeed so please keep in mind this is just food for thought.
You're dead on with regards to the logistics involved in operating this equipment on site, we'll absolutely be facing each of the challenges you mentioned.
Time value of money. There is a lot of capital tied up in those machines. If they stop for a day there is no income from that capital.
Does not invalidate your point, but it blunts it
EDIT: Autonomous forklifts are old tech by now, most container ports are close to be fully automated as are tons of factories all over the world. Heck, we even have automated lawn mowers and hoovers...
And yes, as you said there is still the lost time value of money associated with any equipment that's not doing productive work.
Important to keep in mind, but I would suspect(and hope), most solar farms will be installed, where it is sunny and dry.
Weather patterns on East coast can be unpredictable, much more so than central valley CA. torrential rain = mud leading to bogged down equipment, this can be the difference between a profitable job and unmitigated disaster for an installer.
Second, construction cycles in utility solar can be a bit wonky because of ITC tax credits, lots of turnkey providers looking to have construction starts in q4.
Install labor is relatively cheap but more importantly flexible - relative to the cost of the project install is low double digits %. If a job isn't running smoothly you cut your temps and move your main crew over to another site or send them home if they're local. I would wonder how this work fit in with an automated build/install solution.
Unless you have control at the GC level you're going to be start/stop with electricians cutting trenches in front of you, missing materials (tariffs/port strikes), permitting delays, etc, and you'll have expensive idling equipment that's tough to move.
I get that this is the problem you're trying to solve - but I'd definitely suggest going to enough bread and butter 2-10MW sites where this sort of thing is more common. Also keep in mind Central CA in summer is not Massachusetts in November, weather makes all this 10x worse.