Electric cars line up at the official start of the Zero Emissions Race outside the United Nations Office at Geneva (UNOG), Switzerland. Powered by renewable energy such as solar, wind, wave and geothermal, the vehicles will travel once around the world in 80 days, across 17 countries, for a total of 28,000 kilometres. The race, which emphasizes vehicle efficiency and reliability rather than speed, is supported in part by the United Nations Environment Programme (UNEP).