skylight : A rooftop window that brings in twice the light of a traditional window of the same size.

solar panel: A panel containing cells that convert sunlight into electricity.

sun tunnel : A passage that brings light into a room by bouncing sunlight through a small dome skylight on the roof connected to another skylight on the ceiling of the room. (Also known as a sun tube, sun pipe, and solar tube.)

sustainable: Using natural resources in a way that allows for continued viability.