Economies worldwide are facing the triple challenge of undergoing a fundamental energy transition, improving energy security and accelerating energy efficiency to prevent threatening effects of climate change. Accelerating clean energy deployment and building the necessary infrastructure is crucial to foster decarbonisation across sectors, such as transportation, buildings, and industry. With increasing electrification across sectors, improving energy efficiency is equally crucial as phasing out fossil fuels. What technologies are most promising to transform the US energy system and create resilient energy infrastructure? What will power the future energy system in the US and what policies and investment models will get the US there?