I just had an idea. I'm not sure how to develop it into a story myself, but I thought I'd throw it out there to see if it inspired anyone else.
Suppose something happened to Clark to make it so that his "batteries" no longer stored solar energy. He would still be "super" -- but only in direct sunlight. When he is indoors away from a window, he would be completely un-super. When he is outdoors, his powers would vary depending on whether there are clouds blocking the sun. At night, he might be slightly super depending on how much moonlight there were.
Have any stories like this already been written? Would anyone be interested in running with the idea?
Joy,
Lynn