Global sustainable development critically depends on a fundamental transformation of the current energy system; innovation in cleantech is the key. Current scenarios for sustainable development assume that all countries will follow the technological trajectories prescribed by the globally optimal scenario. But empirically we observe large differences in the ability of countries to do so as success in cleantech innovation is path-dependent; it strongly depends on the history, existing capacities, and resources of a country. The CLEANTECH project has the objective to explain the emergence and uneven rate of cleantech innovation across countries.