Solar Impulse is a plane that uses the power from the sun to power its flight. It has flown round the world, in stages. It’s design is very similar to the albatross, above which can fly for weeks over the oceans without landing. Modern solar panels do not allow the capture of enough energy for a manned plane to stay aloft continuously- maybe in the future technology will allow this. However it is already possible for unmanned planes to fly continuously and rumour has it that the military are already using these silent planes with infinite range as drones for permanent observation of for example suspected terrorists.
Another area where modern design has transformed what can be achieved is sailing. Modern catamaran airfoil boats can reach speeds of over 50 mph and are an impressive sight as they race in the America’s Cup in San Francisco this summer. Very different from the boats used even 20 years ago. The photograph is of Defender in 1992 America’s Cup (Wikipedia).