Floor 0502 was a solar farm on a Mondasian colony ship.

Like floor 0507, it contained a windmill.

Nardole evacuated the children there from floor 0507 as the Twelfth Doctor ignited that floor to destroy the Cybermen attacking it. While talking with Nardole, the Doctor stated that there is livestock held in cryogenic storage somewhere on the floor that the people can use to start over on floor 0502. (TV: The Doctor Falls)