According to the data presented in Section 4.2.2, the average annual market growth rates of solar thermal collectors in the period from 1990 to 2009 and from 2000 to 2009 were 12% and 9%, respectively. The targeted annual growth rate from 2008 to 2020, according to the NREAP, is about 7%. Thus, the NREAP target corresponds to a decreasing market dynamic. A crucial open question in the assessment is when the current slowing down in solar thermal market growth will be turned into a more positive dynamic again.