so we have a county ARES exercise coming up in about three weeks and im trying to nail down the power situation before i commit to hauling everything out there. the EOC wants us to set up a portable net control station in a park about 2 miles from the main building, no shore power obviously.

right now my plan is to run my IC-7300 and a small packet station off a 100ah lithium battery with a 200w panel but the exercise is supposed to run something like 18 hours straight and i dont know if thats going to be enough depending on cloud cover that day. ive got a Honda EU2200i i could throw in the truck but man that thing is another 47 lbs and i hate wrestling it in and out.

the antenna situation im less worried about, planning on a linked dipole up in whatever trees i can find, maybe 30-35 feet if im lucky. done that setup a dozen times. its really just the power budget thats nagging at me. anyone run long duration field ops off solar only and actually had it work out, or is a generator just the right call for anything over 12 hours?

18 hours is doable on solar plus battery if you're not running the amp hard the whole time. the math isnt that scary — IC-7300 at 100w output is pulling maybe 22 amps worst case but you're not transmitting constantly at net control, probably more like 20-30% duty cycle if its a typical voice net. throw in the TNC and whatever else and call it 8-10 average draw. 100ah lithium at say 80% usable is 80ah, so youre looking at roughly 8 hours from the battery alone before you even account for solar input.

200w panel in decent sun should push 10-12 amps into the battery depending on your charge controller and angle. if you can get 6-7 hours of usable sun youre basically breaking even or better. the problem is 'depending on cloud cover' as you said — thats the variable that kills you. i'd bring the honda anyway and just treat it as a backup you hopefully dont need. the peace of mind alone is worth the back strain honestly. last ARRL SET we did i brought mine and never started it, but i was really glad it was in the truck around hour 14 when the sky went gray.

linked dipole in the trees should work great, whats your feedline run looking like? if youre going more than like 50 feet of coax down to the rig at that park you might want to think about where youre actually operating from vs where the antenna is, sometimes i end up with a weird coax run because of where i can actually get a tree and where i need to sit and it introduces more loss than people expect especially if someones donated you a roll of RG-58 or something. not a huge deal on 40m but worth checking.

on the generator thing i pretty much always bring mine to anything over 8 hours. i know its a pain but ive been burned too many times by 'oh the solar will be fine' and then spending the last 4 hours babying the rig at low power trying to stretch the battery. EU2200i is a good choice at least, quiet enough that you can actually have a conversation next to it which matters a lot when you're doing voice ops.