The purpose of this course is to critically examine the technology of energy systems that will be acceptable in a world faced with global warming, local pollution, population increase, and declining supplies of fossil fuels. The focus is on renewable energy sources (wind, solar, geothermal), but other non-carbon emitting sources (nuclear) and reduced carbon sources (co-generative gas turbine plants, fuel cells) are also studied. Both the devices and the overall systems are analyzed.