Investments in sustainable energy are essential in view of economic and population growth, climate change as well as energy security, but face specific risks and inconclusive financial attractiveness. It is generally acknowledged that the current(ly foreseen) level of funding is too low compared to the required investments. At the request of Duisenberg school of finance, this report highlights leading literature and empirical findings on ‘financing of the transition to sustainable energy’, amongst others addressing the business case for sustainable energy investments, the underlying reasons for the current low level of funding and ways to improve this.