An Improved Method for Evaluating Market Value of Turbine Gaspath Component Alternatives

Abstract

The large installed base of large frame industrial gas turbines has prompted a number of replacement part offerings, in addition to the replacement parts offered by the OEM. Willett [1] proposed an economic model developed to evaluate gas turbine component alternatives for base load and cyclic duty operation. The improved method expands the capability of the earlier model by including risk level as a variable. Power plant operator value of alternative replacement turbine components for a popular large frame industrial gas turbines is evaluated. A baseline case is established to represent the current component repair and replacement situation, assuming no risk. Each of the modes of power plant operation is evaluated from a long-term financial focus. A short-term financial focus is evaluated for contrast and discussed briefly. Long-term focus is characterized by a nine-year evaluation period, while short-term focus is based on first year benefit only. Four factors are varied: part price, output increase, simple cycle efficiency increase, and additional risk. Natural gas fuel is considered at two different gas prices. Peak, off-peak, and spot market electricity prices are considered. Results are calculated and compared using net present value (NPV) criteria. A case study is presented to demonstrate the method’s applicability to a range of different risk scenarios, from ill-fitting replacement parts to catastrophic turbine failure.