Just recently after seeing some science fiction film about living in an ice age, I had thought of a game where plantlife would only be possible around large light sources as the sun wouldn't be light enough for that job, just as on some of the planets (or large moons) farther from the sun. This could be a technical device or some plant like them large trees at the beginning of the Silmarillion in Valinor as described by Tolkien. For this to work though the light these sources could spread should reach a lot farther than 16 nodes. If I let a tree grow 100 nodes high the light should spread farther than the tree is high. Right now it would probably not reach the ground from the bottom most leaves.
Being able to use an alternative large light source that lights a considerable area as part of some special game design would be usefull indeed. Not only for fantasy themes but also for science fiction and mining related themes.