Engineering for sustainability is an emerging theme for the twenty-first century, and the need for more environmentally benign electric power systems is a critical part of this new thrust. Renewable energy systems that take advantage of energy sources that won’t diminish over time and are independent of fluctuations in price and availability are playing an ever-increasing role in modern power systems. Wind farms in the United States and Europe have become the fastest growing source of electric power; solar-powered photovoltaic systems are entering the marketplace; fuel cells that will generate electricity without pollution are on the horizon. Moreover, the newest fossil-fueled power plants approach twice the efficiency of the.
