It has grass inside!
I'm guessing
water and sun are coming in the open ends, but the covering looks like it might be transmitingvsome light.
Depending on your climate, it might be a good place to grow lettuce in the summer time.
Kratky hydroponics in gallon buckets?
They could be a good place to park an old camper, or work on cars, or a million other things best done under cover, but what do you actually need?
I'm guessing you aren't a hoarder, since that nice covered space isn't filling up with junk already.
If they were mine, I would want to try out a layer of petrified hussein on one of them, in order to protect the plastic from wind and sun.
I think I would fill one with tree seedlings.
I would on choose ones on the edge of being hardy
enough for my zone, some of the figs or bananas, etc.
It would be a
greenhouse, but the crops wouldn't need a lot of tending or ideal
solar exposure.