This document discusses a selective topics of energy course taught by Dr. Ahmadi Danesh in 92-93. It focuses on sustainability and cogeneration systems (CHP) as presented by researchers Ugar Cakir, Kemal Comali, and Fiker Yuksel from Baybat University in Turkey. The document notes that energy resources are decreasing while dependency is increasing, and highlights the importance of protecting the natural environment for survival. It also discusses using renewable energy resources and increasing energy efficiency. Finally, it provides information on CHP systems, including efficiency rates of 36% at 100% load and 31% at 30% load, as well as efficiency of 81% at 100% load and 75% for loads between 50