Reiner Lemoine Institute (RLI) is an independent, non-profit research institute established in 2010 to support the transition to a future powered entirely by renewable energy. Its applied research focuses on transforming energy systems, renewable-powered mobility, and off-grid systems, combining technical analysis with attention to social and economic factors.

RLI works across topics including green hydrogen, electricity grids, electric vehicle grid integration, rail and bus energy needs, geographic information systems, and community participation in energy planning. Its research examines how to plan and operate infrastructure, integrate new demands into energy networks, and develop sustainable energy solutions in different local contexts.

The institute provides services to support the energy and transport transitions. These include infrastructure and energy-system planning and optimisation, energy management, data analysis and visualisation, strategic studies, and research and development. RLI also shares knowledge through publications, tools, events, and public communication. By applying scientific methods to practical questions, the institute helps organisations and decision-makers assess options and plan for renewable energy systems.