Inner Radiance

Dyson Spheres is an interesting concept. Really, it is the best conceivable way of establishing a completely self-preserving (except taking care of a normal planet, 'cause fuck that). An Alderson sphere, despite being awesome, would be impossibly large, and a ringworld is basically just a planet.
A dyson sphere, however, could consist of a shell with habitable areas, an inner shell that orbits the star, keeping 50% of the outer shell in shadow (thus creating day/night), while also being covered in solar panels. There could also, theoretically, be moons small enough to fit between the inner and outer shell that could be both habitable and fulfill the purpose of a moon.