Fuel Equivalent-Based Steam Pricing

TABLE 17.3. Comparison Between Enthalpy and Work-Based Steam Pricing Methods 

Both enthalpy and work-based steam pricing methods rely on thermodynamic laws as the basis. Cooper (1989) argued that the steam pricing should reflect economic reality. Since the operating cost for a steam system mainly consists of fuel burned for steam generation. Cooper (1989) proposed to use the concept of fuel equivalent (FE) as the basis for steam pricing. In this method, the ratio of FE for steam at different pressures is used to derive the steam prices in placement of the ratios of enthalpy and availability. 

The total FE for each steam header is the summation of all FEs entering the steam header via different flow paths. The speeifie FE for each steam header is the total FE divided by the amount of steam generated from this header, that is. 

A top-down approach is adopted for FE calculations. FEs based on LHV efficiencies for steam raising devices such as on-purpose boilers and waste heat boilers are calculated first Then cascading down in the order of pressure levels, FEs for other steam headers are determined. 

It is common that steam turbines are connected to steam headers. Therefore, it is logical to take power generation into account when steam price is determined. In reality, when the turbine is offline while the motor is online to run the rotating equipment, the power is imported but fuel for steam is saved. On the other hand, when the turbine is turned online while the motor is offline, import power is saved but at the expense of fuel for steam. To reflect the relative price comparison of fuel and power, the price equivalent efflciency (PEE) for power generation is defined as the price ratio  

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