They do say it's a DC based swamp cooler. Looks home made though...more detail on it would be interesting.
Called something like a "Burning Man Bucket Swamp Cooler":
https://eplaya.burningman.org/viewtopic.php?t=33842
Simple and cheap to make; the problem with swamp coolers at Burning Man is the dust. Eventually the water turns to mud, and the pads get caked in it. Plus, you have to carry enough water not just for drinking, but to run the cooler too.
But that's at Burning Man - in other contexts it works as well as any other similar cooler.
I was under the impression swamp coolers needed big air flow to work well. Seems maybe not?
According to the chart at the bottom of this article, it's not optimal, but it'll take the edge off: https://www.air-n-water.com/common-swamp-mistakes.htm. And for most summers, this one being an exception, our problems with heat are in the high desert east of the mountains.
But now you've got me thinking about some WiFi or LTE module that monitors continuity or voltage, build a companion phone app that gets pinged when $SOMETHING goes wrong. :-) (Our use case is bluegrass festival->leave dogs in camper to see show, so we're never very far away.)
There exist smartphones with ambient temperature sensors; if you already have USB power, this is only a few hours of hacking.
Duh, of course. That's why they don't let me design things. :-) (Though in my defense, it was an "off the top of my head in 500ms" thought.) Plenty of power available, the only issue would be connectivity, as there's about a 50% chance that any festival we go to won't have a cell signal. Which makes me wonder how hard it would be to rig something that sends an APRS message over amateur radio frequencies when a the alarm has voltage, or something.
Anyhoo, this is drifting way off topic. If I get around to making something, I'll post a Show HN.
big power hungry fan motor
I would have concerns with a 100 watt DC panel being able to handle a 65 watts AC swamp cooler. Conversion loss, motor startup current draw, etc.
Big alternating current fans that can move air do use lots of power. Especially a current surge at startup.
It sounds like in this space, people are making their own direct DC powered swamp coolers that are using less power, with relatively low flow fans. That's what I was missing.