the extent to which companies are exempted might be reduced – by increasing their comparatively small share of FiT payments. Furthermore, exemptions might get linked to prerequisites like the introduction of an energy management system in the respective companies. The necessity and urgency of such reforms is accelerated by the EU Commissioner for Competition, Almunias, who is requesting reforms, claiming that the existing exemption rules might be a subsidy in violation of EU competition law. 29 Conclusions Promoting renewable electricity is a good means of furthering energy security by using energy sources available domestically and protecting the climate by avoiding CO 2 emissions from electricity production. At the same time, other risks related to many conventional energy sources are avoided, e.g. • Health risks related to coal dust or nuclear contamination; • Environmental risks related to the unsolved problems of disposal of nuclear waste; • Security risks related to potential terrorist attacks, e.g., on a nuclear plant. FiTs have proven to be a convincing instrument for RE expansion. With the right design, it can be considered both efficient and effective. Unsurprisingly, the instrument has enjoyed a high level of political support across the world and has been implemented in a rapidly growing number of countries. The experiences gained with this instrument in different nations and over different stages of RE development are a valuable source of information for future FiT design options. Ultimately, however, policy-makers will always have to take into account the specific circumstances and RE potential in their respective jurisdiction. Some design elements of a FiT have, however, proven to be important for a successful regime: • The FiT design will have to provide transparency, longevity and certainty to be attractive to investors. • The FiTs have to incentivize the desired level of investment while avoiding excessive rents to RE generators. This is a central challenge and will require regular revisiting and adjustment of tariffs. 29 Stratmann(2013). 15