Coal has long been the major fossil fuel used to produce electricity. The existing coal-fired power generation fleet consists of over fifteen hundred separate units ranging in size from just a few megawatts (MW) to thirteen hundred (1,300) MW. Together these coal-fired power plants (CFPPs) constitute over 300 gigawatts (GW) of installed electric generating capacity and are responsible for generating more electricity than any other fuel type in the United Sates: between thirty-seven and fifty percent of the total kilowatt-hours (kWh) produced annually during the last decade. However, coal-fired electric power plants are one of the largest sources of air pollution in the United States, with greenhouse gas (GHG) emissions from burning of fossil fuels believed to be the major contributor to global climate change. This book discusses efficiency improvement options of coal-fired power plants.