Firms must weigh various co-generation options

Design and operating considerations are reviewed for coal- and lignite-fired co-generation plants. The plants are designed to meet specific power and steam needs of one or more industrial plants. The factors considered are site, boiler type, reliability, flexibility, process obsolescence, coal supply and ash removal logistics, environment, and financing. To operate at maximum efficiency, the plant's size is limited by the amount of process steam required. The flexibility of the extraction/condensing steam turbine cycle, which permits its use for base-load power generation, will improve capital formation. Air-quality requirements will probably make central plants more feasible than individual facilities. Several financing alternatives are listed, and it is pointed out that this type of investment is generally low-risk. Investment tax credits are expected to help develop low-cost financing. (DCK)