Economic Analysis of Hybrid Chiller Plants About the Author T

raditionally, chiller plants in large facilities consisted of constant-speed, electric-drive centrifugal chillers because they were the least ex-pensive and most efficient option. Although natural gas was cheaper than electricity on a $/Btu basis, the price difference wasn’t sufficient to offset the efficiency and capital-cost differences between electric and non-electric chillers. In the past few years, the metrics have changed. Today, hybrid chiller plants using multiple chillers and different energy sources are being con-sidered in many applications. What has changed? A significant factor is the new time-of-use rate structure