I know that some people don’t think that energy efficiency is very compelling, but there are a lot of astronauts who would disagree with that. In space, energy efficiency literally saves lives. When Apollo 13 lost electrical power, the astronauts’ survival came down to their ability to conserve enough energy to bring them back to Earth. After shutting down all “unnecessary” systems, how much power do you think they had? The equivalent of what it takes to run a coffee pot. Amazing.