Peaking Capacity Enhancement Of ABB 11N1 With Thermal Energy Storage


Sanjeev Jolly, P.E.
Joseph Nitzkin, P.E.
Donald Shepherd,
Cladwell Energy & Environmental, Inc.
Louisville, Kentucky, USA

Douglas T. Eberlin, P.E.
Wisconsin Electric
Milwaukee, Wisconsin


Many electrical utilities are experiencing increased seasonal demand due to air conditioning use. Current air quality rules and regulatory changes in the industry favor the installation of combustion turbines (CT) for new generation capacity. Ironically, CT output declines as ambient temperature increases. As the output of a combustion turbine degrades during hot weather conditions, warm ambient air to the compressor inlet can be chilled to restore lost capacity. For a thermal energy storage (TES) system, a refrigeration system is utilized to build a cold energy reserve and this reserve is used to cool inlet air during peak hours to enhance turbine capacity. Typically, a TES system can be installed at half the cost of installing a new turbine. Two such systems were installed at Wisconsin Electric’s (WE) Concord and Paris Generating Stations, each having four ABB 11N1 combustion turbines running in simple cycle mode, This paper discusses the feasibility study and design for a TES based inlet chilling system to provide peaking capacity enhancement for these ABB 11n1 machines. The system design is based on cooling the inlet air for 4 hours a day, 5 days a week. Each of these systems includes a 3,200 ton refrigerant plant, two 2 1/4 million gallon tanks, and 2,500 tons of ice-making capacity. The instantaneous cooling load for each set of 4 turbines is 16,700 tons. With this Combustion Turbine Inlet Air Cooling System (CTIAC), a total gain of more than 112 MW (approximately 17%) was expected for the two plants, making it the world’s largest inlet air cooling system. Finally, the system performance is discussed during summer operation.

To continue reading, please enter the following information:

    Your Name*

    Your Email*



    Your Message