The German Renewable Energy Law (EEG) has without doubt fostered the strong increase in renewable energy in Germany. It has been criticized though for its high cost and a too rapid and cost-intensive development of renewable energy. The 2017-reform of the EEG tries to address these two criticisms by moving from feed-in-tariffs to competitive procurements by tender to manage future development of renewable energy. Still, it wants to maintain diversity of investors to give also small renewable energy firms and citizen-co-operations a chance to participate in the tenders. This article evaluates the 2017-reform of the EEG based on the criteria cost-efficiency, innovation effects and ecological effectivity. It concludes that the EEG 2017 improves the preconditions for a controlled development of renewable energy and has the potential to increase cost-efficiency. Yet, there is potentially a negative impact on investor diversity and the readiness to invest.