Fast Company: Got a bright idea? How about an energy-saving one? GE announced today a $200 million “open innovation challenge” that invites inventors, entrepreneurs, and startups of all stripes to compete to develop the next-generation of power grid technologies. Called the Ecomagination Challenge, this huge investment comes only weeks after GE announced a $10 billion injection into its own eco-R&D projects. Along with four VC firms that have pledged half of the $200 million to the challenge, …