ABSTRACT
Currently two main instruments are dominating the discussion on how to promote renewable power most efficiently. The first historically is the feed-in tariff (here abbreviated as REFIT, for renewable energy feed-in tariff), set in advance for a considerable length of time. The second is the system of tradeable green certificates combined with minimum quotas for renewable power, here abbreviated as RPS (renewable portfolio standard, the term used in the United States where this system was first introduced) or TGC (tradeable green certificates, an essential feature of such a quota system).
