October 15, 2008

J.K. Spruce Power Plant, Unit 1, San Antonio, Texas

Dr. Robert Peltier, PE

Owner/Operator: CPS Energy

CPS Energy’s J.K. Spruce Power Plant, Unit 1 was recently recognized by the EUCG Fossil Productivity Committee as the best performer in the large coal plant category over the 2002-2006 evaluation period. The competition was tough, with more than 80 plants in the running, but Unit 1 emerged as the clear winner by earning top points for high plant reliability and very low nonfuel O&M costs.

At its fall meeting, the EUCG’s Fossil Productivity Committee selects a large (>250 MW) and small (<250 MW) coal-fired power plant as its members’ best performers over a five-year period. The reigning champion in the large coal category is CPS Energy’s 585-MW J.K. Spruce Power Plant, Unit 1 (Spruce 1), located southeast of downtown San Antonio on Calavaras Lake. (The EUCG winner in the small coal category winner is profiled. See Cover Story,"Dubuque Generating Station, Dubuque, Iowa".)

The selection criteria for the best performer are simple and equitable in concept but require a rather lengthy statistical exercise. All the coal-fired power plants from EUCG member utilities submit cost and reliability data for the sample years, in this case 2002 through 2006. The cost data cover operations and maintenance (O&M) costs on a $/MWh basis, and reliability data are calculated from an agreed-upon definition of equivalent forced outage factor: forced outage hours, plus equivalent forced derated hours divided by the sum of service hours, plus forced outage hours, plus equivalent forced derated hours during reserve shutdown. The data are then corrected to factor out variables such as plant rating, capacity factor, and number of units on the plant site to create a level playing field. Each plant is then ranked in both of the categories, and those rankings are then combined to determine the overall winner.

What’s unusual with these awards is that a plant doesn’t have to win one or both categories to be selected as the best performer; rather, it must have a strong showing in both categories to win, which is how the Spruce unit won.

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