Magnetically inflated cables can spring open a large (kilometer or larger) membrane space structure This can be used to make massive space telescopes, solar power collection systems, solar thermal propulsion and many other structures. This looks like one of the most simple and straight forward yet highest potential of all of the new Nasa institute of Advanced Concept ideas. This idea and the plasma magnets look like major winners.
Solar electric power systems at 10km in diameter could generate 18 GW at 20% efficiency. Networks of powered and cooled superconducting cables that would hold massive structures rigid in space. Existing superconducting cable should work. Better superconducting cable can make the systems work even better.