Engineers are getting better and better at reducing the energy use in structures of all kinds, approaching the goal of buildings that need no outside power. This office building in Golden, Colorado may actually achieve that goal by the time it is completed, and at a reasonable cost. With commercial buildings accounting for 18 percent of US energy use, this is a far from trivial achievement. No radical new technologies are needed, just a small array of solar panels and the rigorous application of every energy saving trick in the book.
Of course, Golden, Colorado is the sort of place where everybody drives everywhere, so I am not sure that the overall impact will be less than a conventional building in Manhattan. Still, every bit of savings helps.