Energy entrepreneurs are invited to compete for a cash prize and the chance to network with investors. The German Energy Agency has launched Start Up Energy Transition, a global business competition open to start-ups and early-stage energy companies. Entrants can compete in five categories: Urban Energy Transition, for contributions to digitally enabled and sustainable cities; Cleantech Against Climate Change, for technologies that cut greenhouse-gas emissions; Future Production and Manufacturing, for digital solutions; Mobility Meets Energy Transition, for sustainable mobility concepts; and Platforms and Communities, for networks expansion. Entrants can also compete for a grand prize, Start Up SDG7, for companies or products that contribute to clean, affordable energy. Results will be announced in 2017. Category winners will each receive €10,000 (US$10,400); the grand prize, a package worth €20,000, will be shared between three nominees. All entrants will have the chance to network with venture-capital representatives, industry partners and other start-ups. Applications may be submitted up to 31 January at go.nature.com/2hvk72h.