Solar Fans - cooling of critters and growies

Hi there y'all,
Searching the forums and hopefully this is the right place to post. More of a critter barn than greenhouse questions. However a solar fan, would be good and work for a growies too.

I have two barns and chicken coop. The goal is to have each structure provide it's own water and electric. So far I've got the water with rain water collections.

Next is electric for the jumper box and fans. The red barn has a feed room that is mostly sealed. It's about an 8x10ft room. Our summers our hot and sticky.

Right now, i have an extension cord run for probably too long of a run. It goes from my house to the barn. The corded electric powers the jumper for an electric fence and two fans. One fan is a small exhaust fan pulling heat from the feed room. The other fan is placed just above the divider wall, blowing air on the critters. Ideally I'd like to replace the fans with solar fans or learn how to rig a small solar system.
(side note: i have a solar jumper box for the portable electric fence. allowing the pasture to be divided into smaller areas to maximize rotations. I could possibly get another solar jump box to replace the corded one)
*BUT this post is about solar fans. :)

Reading reviews, it seems solar fans are small and best suited to small coops and small greenhouses.

has anyone installed and used a solar fan for a greenhouse, coop or barn?
what are other ways to move air and keep animals cool during humid summers?

attached is pic of the barn, the opening faces east. I had it orientated this way so the feed room would sort of shelter the stalls from the SW summer sun. Barns always get muddy near doors. Figure the doors/openings facing east get enough sun to grow grass and keep from turning into mud.

Hi Sena.  Here is a cost effective fan system we use.

That is cool. I just want the fans to run during the daylight hours. no need for batteries or switches here either.
thanks for the video. think i may have to piece something together too. most solar fan kits seem to have low wattage panels and small fans.

thanks for your help. much appreciate it.