Over the period of the study, 2009 to 2013, there are many major amendments to the feed-in tariff incentives and other policies. The amendments mostly occur in the middle of the year, particularly in June or in July.
The amendment of German solar feed-in tariff in 2010 is one of two big changes that occurred during the studied period. The German parliament or the Bundestag approved the reduction of feed-in tariffs on May 6, 2010. However, the federal council or the Bundesrat refused the proposal. The mediation committee had to work on figuring the best solution for both parties. Finally, the compromised solution came out on July 5, 2010. And the bundestag agreed on the revised one after. The amendment stated that the solar feed-in tariff rate would be adjusted downward as of July 1, 2010 and October 1, 2010 respectively. The publication of the EEG 2010 amendments was issued on August 17, 2010. The effect, however, went into effect retroactively starting on July 1, 2010. The table below is the summarized table of the change of feed-in tariff rate. Nevertheless, the change of the degression depends on the additional installed capacity of solar photovoltaic.