I imagine another outcome to this alternate history of Superman. All those years as the “transitional power source” have driven him somewhat insane, or perhaps just really bitter. When he is finally put out to pasture, Superman realizes that he must justify his existence to the people of Earth, so he invents a new supervillain (that is him).
Superman decides to call him Namrepus (because he was never a terribly bright super-hero), and threatens to destroy the Earth if the humans do provide 10,000 virgins to him so that he may repopulate another world with his human/kryptonian offspring.
A first virgin is chosen, and Namrepus comes to take her away. (His costume is the reverse of superman’s, with blue underoos and cape, red unitard, and an insignia with a backwards ‘s’, because Superman is so committed to the backwards name thing, he does not stop to think that a real supervillain called Namrepus would have an ‘n’.)
The virgin is wearing a pendant of gold kryptonite, which temporarily removes Superman’s powers, and he is sent to Arkham Asylum.
There, Superman becomes good friends with Mr. Freeze. Eventually, they are rehabilitated, and they become successful businessmen, selling designer ice sculptures and bottled water products, made of ice gathered from the asteroid belt.
NOTE: The Flash could also be used as an excellent power source. Just put him in a hamster wheel attached to a power generator.