Cooling Semiconductor Manufacturing Facilities with Chilled Water Storage

This paper examines the 5.2 million gallon chilled water storage system installed at TI's Expressway manufacturing complex in Dallas, Texas. During the peak cooling season ending September 30, 1994, it provided 3,750 tons of additional peak cooling capacity for a new semiconductor factory named DP1/DMOS5 and, at the same time, shifted 5,100 kW of existing cooling electricity demand from daytime to nighttime, when high voltage power is $9/kW (75%) less expensive. As a result, installation of a conventional water chilling plant to serve DP1/DMOS5 was avoided, saving $5.0 million (net) in capital and reducing the new semiconductor factory's size, complexity, and construction schedule. Furthermore, the existing 29,000 ton cooling district and operations staff now produce 1.75 million additional ton-hours/year of cooling without the additional operating expenses associated with a new conventional water chilling plant and operations staff -yielding a dramatic improvement in productivity. Net operating cost savings (including energy cost savings) total $1.5 million/year