Gossamer Albatross - In 1979 this human-powered plane flew across the English Channel and claimed the largest prize in aviation history. Another of these planes is displayed at the National Air and Space Museum.
Gossamer Penguin - A solar-powered variant of the Gossamer Albatross.
Pathfinder and Pathfinder Plus - This unmanned plane, built by AeroVironment as a part of the NASA ERAST Program, demonstrated that an airplane could stay aloft for an extended period of time fueled purely by solar power. After initial successes, the Pathfinder was rebuilt into the larger Pathfinder Plus, which is also on display at the National Air and Space Museum.