Limiting global warming to well below 2°C, as stated in the Paris Agreement, requires a transition to a low-carbon economy almost exclusively using renewable and clean energy technologies. Substantial investment is required for the innovation of new technologies or improvements of existing technologies. In our article (co-authored with Ulf Moslener and Oliver Schenker), we focus on the role of financing costs. Our motivation stems from both the literature and experiences from our colleagues at the Frankfurt School – UNEP Collaborating Centre, who have worked in numerous projects with both clean energy firms and developers as well as financial institutions.