By most measures, Reykjavik tops the list of energy efficient cities worldwide. Along with the rest of Iceland, Reykjavik relies on renewable hydropower and geothermal plants to provide all of the heat, electricity, and hot water for its more than 120,000 citizens. The Nesjavellir geothermal power station services all of the space heating and hot water needs of the greater Reykjavik area. The city plans on becoming fossil fuel-free by 2050 and the final piece of that puzzle is hydrogen power. In the mid-2000s, the city began replacing its public transportation with hydrogen-fueled buses. The only “pollution” emitted from these vehicles is pure water. Although Iceland may be a small country, it’s big energy ambitions are leading the way for the rest of the world.