This report serves as a background report of the main report of the Assessment and Dissemination activity on Major Investment Opportunities for Renewable electricity in Europe using the REBUS tool (ADMIRE REBUS) project. The report focuses on challenges that arise from changes in political support systems, lead time, and risk with respect to investment in renewable energy sources for electricity (RES-E) technologies. It discusses which tools and strategies can be used in order to overcome these challenges. The objective of this report is to elaborate further on the above-mentioned discussions compared to the main report, mainly through illustrative case studies with data taken from questionnaire analyses and data surveys.