Natural Gas-Electric Hybrid Cooling System for Army Facilities - A decision Tool

摘要

Operation of space cooling equipment accounts for more than half of the annual peak electrical demand and a third of the total electrical energy consumed in a typical Army installation. As a means to reduce the peak electrical demand in kilowatts and electrical energy consumption in kilowatt- hours, a number of Army installations installed natural gas engine chillers during the 1990s through Congressional appropriations, the Federal Energy Management Program (FEMP), and installation operations and maintenance (O&M) funds. This report reviews field performance of these systems and provides a selection guide for cooling systems in the Army installations. Life-cycle cost analysis of chillers in three ranges of cooling capacity was conducted to determine the economical benefit of hybrid cooling systems. The capacity ranges are: less than 50 tons, 50-200 tons, and greater than 200 tons, which correspond to typical small administration buildings, barrack or large office buildings, and central cooling plant applications, respectively. The study results show that the electric-gas hybrid cooling system is recommended only when a favorable fuel cost rate is available for natural gas compared to electricity.