Solar Impulse in comparison !

SI 1 has 91 grams the forward piece of wing foil..this craft ( Hippiäinen ) has around 23 grams...but I have a lot lesser need for the wing foils due to the geometry/dimensions of the foils...about ½ of the foils that are needed in Solar Impulse ( per every running meter ) ! http://www.cbsnews.com/news/solar-powered-plane-aims-to-fly-around-the-world/2/