Balancing Energy Efficiency And Costeffectiveness Evaluation System For Chiller Plant With Thermal Storage

Chiller plant with thermal storage, normally using water or ice, are often used in cities with stressed peak power supply, encouraged by huge difference of peak and bottom electricity tariffs. However, debate on the operational energy performance as well as economic benefit is never stopped and reported results were polarized. It is necessary to build an evaluation system for thermal energy storage systems.An evaluation system balancing on both energy and economic aspects for chiller plants with thermal storage will be presented in this paper. The evaluation system consist of hierarchical indexes based on measured data from real operating chiller plants and an analysis method to support every steps in the whole life cycle of a thermal storage system. The method also gives an advice when making decision about the scale of thermal storage by using the indexes of LCC/Q and IRR: from all the schemes that IRR is less than the industry average value, choose the one with lowest LCC/Q.Despite making assessment for chiller plants the evaluation system can also help to regulate and improve the process of designing, construction and operation. When a chiller plant with thermal energy storage is well built and managed, it will contribute to the economic benefit and energy saving of both buildings' owners and the power gird.