Authors’ Summary. This case study provides a quantitative overview of the financial resources mobilised globally as fundamental inputs into the energy technology innovation system. Available data from a diverse range of sources are compiled and summarised throughout the innovation life cycle from research and development (R$D) through market formation to widespread market diffusion. Attention is paid to the less well-reported types of financial resource inputs including private (as well as public) R&D and niche market investments by risk-taking venture capital. The resulting synthesis provides a first-order snapshot of relevant financial flows for energy technology innovation, and provides a framework to situate additional detailed case studies on research, development, and demonstration (RD&D) expenditures outside the IEA member countries, and commercial or "diffusion" investments into end-use technologies. Taken together, these case studies paint a comprehensive picture of financial resources mobilised for energy technology innovation. The key elements of this picture are: (1) the scale of resource mobilisation increases dramatically across successive innovation stages; (2) the structure of current energy investments is highly asymmetrical, with end-use technologies dominating diffusion investments but energy supply technologies, particularly fossil fuels and nuclear energy, dominating early stage innovation investments; (3) six major emerging energy economies now account for a significant proportion of global energy innovation investments. These findings point to the need for new institutional arrangements for the comprehensive and systematic gathering and assessment of energy innovation investments to inform decision making.