The number of commercial solar power plants has been increasing in the last few years. New installations include the 10-MW (PS10) and the 20-MW (PS20) power tower (Fig. 7) plants; the 50-MW Solnova 1 and Solnova 3 trough plants designed, built, and operated by Abengoa Solar near Seville in Southern Spain; and the 50 MW Andasol 1 and Andasol 2 plants owned by ACS Group.