Economical Energy Storage Option Enhances Energy Purchasing Strategies

Abstract

Chilled Water Thermal Energy Storage (TES) offers benefits to both the electricity supplier and the electricity user. This well-established technology uses stratified chilled water to store energy in thermal form so that electricity can be purchased during off-peak periods for use during on-peak periods. This energy shift offers both the user and the generator an opportunity to match their needs to get a win-win arrangement. The advantages to the electricity user not only include lower energy costs (due to reduced demand charges or other means). Chilled Water TES has also been shown to provide added cooling for less than the chiller equipment that it offsets. Finally, the various non-standard rate structures available today offer opportunities for electricity users who have some control over their demand profile. For the electricity generator, Chilled Water TES shifts electrical load from on-peak periods to off-peak periods. This has the effect of increasing the demand for base-load power while decreasing the demand for peaking power. Also, since Chilled Water TES installations are usually fairly large (1 MW or more per site), a small number of installations will produce a significant impact on the generator’s peaking power generation requirements.