Comparison of energy performance and economics of chilled water thermal storage and conventional air-conditioning systems

During the summer of previous years, Kuwait faced a series of power shortages emphasizing the need for urgent commissioning of power generation projects. It is estimated that the demand for electricity is growing at an average of 5.4% per year, encouraged by government subsidies and driven by the rapid and continual expansion in building construction, urban development, and heavy reliance on air-conditioning (AC) systems for the cooling of buildings. The chilled water thermal storage (CWTS) system is one of the available techniques that can be utilized to reduce peak electricity demand of buildings when national electricity consumption is at its highest level. This paper demonstrates that the implementation of CWTS system reduces the peak power demand of AC systems for design day conditions by 36.7-87.5% and annual energy consumption by between 4.5% and 6.9% compared with conventional systems, where chillers and pumps significantly contribute to this reduction. In addition, the Life Cycle Cost (LCC) was estimated for both the Ministry of Electricity and Water (MEW) and the consumer. Results show that CWTS operating with a load leveling strategy gives the lowest LCC compared to 50% demand limiting and full storage strategies, and is, therefore, considered as the most cost effective option for both MEW and consumer. (C) 2013 Elsevier B.V. All rights reserved.