If you're completely off-grid and without a single battery you might have to either increase the capacity well over your consumption or be ready to turn them even three times a day when it comes to rain or cloud as the efficiency drops quite a lot.
I've never heard of somebody powering on and off their miners each day for a long period of time so not sure how this would affect the machines.
If you mine for "free" for 4 hours a day you will simply recoup your investment in a twice as long period as when mining 8 hours. You will make a profit, that's for sure, but recovering all the investments before gears either break down or start making less and less money per TH/s, will be tricky at current prices you're looking at 3 years of shutting and turning them off...assuming no rainy, cloudy days.
Check how the NEM policy works right now in California, I know they are updating it constantly and there is a whole mess right now, so if it will still be viable for small operations go for it rather than taking risk off-grid.
For a single s19 that would burn 40kwh for the night, you would need $10k for the batteries if we go for the cheapest solutions, and you're going at current rates to make $14 during that time per day , making up for the batteries in 700 days. You decide!
The only guy I know using batteries has a deal with a golf cart builder. He takes the poorest quality 'core' returned batteries and refurbs them.
So his 'lead' Battery cost is cheap.
https://www.golfcartgarage.com/8-volt-golf-cart-batteries-trojan-battery-t-875-8v-170ah-6-pack-48v/
a pack. above is purchased by a golf cart owner and the owner returns the 8 dead core batteries .
Some have ruptured dead cells which do not really well. but if that 6 pack of core returns has 3 two cells that can refurb that means 3 x 2 = 6 cells which will do 12volts shit for a golf cart but good for a diy guy. He gets core's very cheap if one or more cell if really bad.
it is the only way I know to make battery solar work. you can see the price for that pack new is 1339 and is a 48volt 170 amp bartery which will do 6 amps of draw to generate 1 amp of 240volt
psu. an s17 is 10 amps so that pack can run down ½ or 8 hours that means you need two sets to do 1 s17 24/7 so at retail your batteries cost you 2600 for 1 s17
and they will die off in 2-3 years. The rest of the solar gear should last over 15 years
Now he will get the 'bad' cores with big markdowns. he may pay 500 or 600 for enough cores to last 2-3 years way better than 2600 for retail
I do not know cali laws for solar but I am fairly sure they suck.