Efficiency and effectiveness of promotion systems for electricity generation from renewable energy sources - lessons from EU countries

Currently, a wide range of strategies is implemented in different countries to increase the share of electricity from renewable energy sources (RES-E). A still controversial discussion is whether quantity-driven (like Tradable Green Certificates (TGCs) based on quotas) or price-driven (like feed-in-tariffs (FIT)) instruments lead to preferable solutions for society. The core objective of this paper is to compare the perspectives of quota-based certificate trading systems for an efficient and effective increase of RES-E with FIT. The major results of this analysis are: (i) The success stories of growth in RES-E in EU member states in recent years has been triggered by FIT implemented in a technology-specific manner at modest costs for European citizens; (ii) At present, TGC systems in most countries applied show a low effectiveness with respect to RES-E deployment of less mature technologies such as solar PV (with improving tendencies in e.g. the UK or Italy with respect to certain technologies); (iii) Compared to short term trading in TGC markets the intrinsic stability of FIT systems appears to be a key element for success; (iv) Hence, currently a well-designed (dynamic) FIT system provides a certain deployment of RES-E in the shortest time and at lowest costs for society.