Reliable steam: To cogenerate or not to cogenerate?

Leading industrial companies and institutions are forever seeking new and better ways to reduce their expenses, reduce waste, meet environmental standards, and, in general, improve their bottom-line. One approach to achieving all of these goals is a 100 year-old concept, cogeneration. Many industrial and institutional plants need thermal energy, generally as steam, for manufacturing processes and heating. They also need electric power for motors, lighting, compressed air and air conditioning. Traditionally, these fundamental needs are met separately. Steam is produced with industrial boilers and electricity is purchased from a local utility company. However, these needs can be met at the same time with cogeneration, using the same heat source. Cogeneration is the concurrent production of electrical power and thermal energy from the same heat source. Large steam users commonly take advantage of cogeneration by using high pressure steam with a back pressure turbine to generate electricity, and extract lower pressure steam from the turbine exhaust for their process needs. This approach reduces their electric utility bills while still providing thermal energy for industrial processes. The result is also a more efficient process that uses less total heat and discharges less smoke up the stack. Newer technologies are making cogeneration opportunitiesmore » available to smaller-sized thermal plants, and electric utility deregulation opportunities are causing many CEOs to seriously consider cogeneration in their manufacturing plants. Whether steam is created through cogeneration or separate generation, many opportunities exist to improve productivity in the distribution system, operation, and maintenance. These opportunities are captured by taking a systems approach, which is promoted by programs such as the Department of Energy's Steam Challenge.« less