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Summary

A new 8 million gallon above-ground stratified thermal energy storage system (TESS) is now operating to shift the chiller dispatch at the 60,000 ton capacity central plant. The presentation will provide an overview of TES technology, applications, materials, construction, and operation. The new TESS reduces the peak demand of the chiller plant by 1-2 5,000 ton chillers during the peak load and electrical cost period of the day. The TESS will also be leveraged to allow for upcoming replacement of two older 5,000 ton HCFC-22 units with a new 12,000 ton series counterflow chiller system consisting of two pairs of packaged 3,000 ton chillers that reduce GWP, and increase capacity and efficiency.The NIH Central Utility Plant (CUP) houses twelve 5,000-ton chillers that serve 11.8 million square feet through seven miles of distribution. The chillers consume about 165,000 megawatt hours (MWh) of electricity per year, roughly equivalent to the electrical energy required to air condition 100,000 Maryland households for a year. The total energy use (fuel and electricity) at NIH is equivalent to the energy used by 50,000 average Maryland homes. The electric cost to run just one chiller for one day is $8,300; to run all 12 for one day (required during the hottest summer days) is almost $100,000. The new TESS will allow the NIH to shift operation of chillers to more efficient and lower cost times of day while also enabling a phased replacement of older chiller systems in the plant to further increase capacity, resiliency, and efficiency.

Session 2C: Thermal Energy Storage

Speakers

Taiyo Asano, National Institutes of Health
Nate Cesarz, Affiliated Engineers, Inc. 
Colin Moyer, Affiliated Engineers, Inc.