Dillon, whoa, 8000 watts is big! That might be two pallets worth. I’ll likely use one pallet full of panels of the highest efficiency [~17%] I can find as shipping on a pallet full is cheapest cost per panel and easiest for the shipper too. Actually it is called “freight” when it’s a pallet full and goes down into a cheaper rate than “shipping”. Way cheaper per panel rate in bulk but still can be $300-$400 for the pallet load. By the pallet is what I recommend to folks looking for panels. Or split a pallet load with someone else.
So it’s not very scientific doing it this way. More practical. I call it “growing a system”. A pallet is usually between 20-24 medium sized panels. So 20@200 watts, for example, is 4000 watts to 4800 watts. Plenty for a simple 120 volt workshop. But I forgot to mention charging my goal of charging a golf cart. Now it’s starting to stretch the the system. Grid tied simplifies system design and use greatly. The golf cart can charge from solar during the day mostly using grid use timers. With the grid available as backup for the nights just in case.
Another big savings is to use locally available unistrut for the solar array racking. Sometimes it’s called superstrut. I’ve built many racks, tilting, flat, or sloped with only unistrut, bolts and the unistrut joining plates. No welding required. 40,000 miles on my cargo trailer rack and I haven’t found a loose bolt yet. Welding is a nice luxury but not necessary most of the time. Unistrut even makes heavy hinges for building a tilting array OR big gate hinges from a hardware store can be bolted on. Also the panels bolt right into unistrut with 1/4” *20 thread “clamp nuts” that slide down the unistrut track. Use stainless bolts and washers.
My van has 240 watts and two @60 AH batteries on it. I can run small power tools but have not tested how long for with the van. I try to never run my batteries below 50% depth of discharge so bring the cargo trailer, inverter technology generator, or both if it’s a lengthy job. The inverter technology generator starts, depending on sunshine on the panels and battery state of charge, if I’m going to run a power tool or load for a long time.
I like to have 800 watts or more if possible. I like to have extra panels then think of ways to use the features of PWM load diversion to use the surplus energy for hot water. Load diversion or auxiliary relays are standard on many charge controllers. Building a energy system involves a lot of “sizing” components. For example, my inverter runs on 24 volts DC. A 30 amp charge controller is rated for 720 watts at 24 volts. So in this example a 800 watt solar array is a good size. The charge controller limits the current and dissipates surplus energy in the form of heat but that isn’t likeky to happen. Maybe dissipates for a few seconds with “edge of cloud effect”.
Having a huge heavy battery may not be practical if one is driving long distances or everyday. Having a inverter technology generator and a little fuel as backup weighs much less. My cargo trailer has 6@ 60AH batteries (roughly 350 lbs). So it’s about trade offs. I’ve never heard anyone say “I’ve got too many panels” lol. Yet to see any in the thrift stores. That’ll be the good day.