Combined cycle/TES plant can save $1,244,474 per year. Proposed cogen system for a 1,100,000-ft{sup 2} medical complex has a payback period of 2.6 years

Abstract

This article presents a comparative analysis between an innovative proposed, combined heating/cooling cogeneration power plant and a base plant for an approximately 1.1 million ft{sup 2} hospital/office complex to be located in Toledo, Ohio. The complex consists of three buildings: a six-story hospital and two identical 12-story office towers. The comparative analysis between the two plants has shown substantial cost savings for the proposed plant because of reduction in utility and maintenance costs and, therefore, the total annual operating costs of the overall plant. This reduction in operating costs is mainly due to the fact that approximately 95% of the total required annual electrical power is produced on-site by cogeneration, and therefore only 5% of its annual estimated power needs are needed to be purchased from a utility. Reduction in the number of plant operators for the proposed plant has also made sizable contribution to the annual operating cost savings. Although the installed first cost of the proposed plant was higher in comparison, the total operating cost savings of $1,244,474 per year has resulted in a cost-effective simple payback period of 2.6 years for the proposed plant. Additionally, the design of the proposed plant has resulted in a substantially compactmore » central plant (an approximately 29% decrease in physical size) in comparison to the base plant having three separate central plants. The fully dedicated proposed plant contributes to reduced demand charges associated with the time-of-use electrical rates, better operation and maintenance, efficient energy management, higher overall system efficiency, and reduced levels of emissions and noise. With the anticipated nationwide deregulation of the electric utility industry (already underway in 40 states), the proposed plant can offer viable solutions to electric, steam, heating and cooling generation needs for large multi-building complexes.« less