Ice Thermal Storage: Old Technology Finds New Popularity
Ice thermal storage is not a new technology, having been used in the dairy industry since the 1930s, but it is surging in popularity as a way to save energy and reduce one’s environmental footprint. Utilizing low-temperature water from ice built during overnight off-peak hours can substantially lower utility costs in commercial, industrial, and now even residential applications.
Ice thermal storage systems rely on inexpensive nighttime electricity to make ice inside storage tanks, which is then melted to provide a steady source of chilled water during peak daytime hours. Air conditioning can demand huge amounts of energy during peak hours, and day-to-night kWh costs can vary by 500 to as much as 1,000 percent. Because ice thermal storage shifts the demand to off-peak hours, energy savings can be very substantial.
The up-front costs of ice thermal storage systems are usually the same or lower than that of traditional systems due to the fact that they require smaller chillers, cooling towers, pumps, and piping than the traditional system. Ductwork, fans, and motor sizes can be reduced as well. Since smaller equipment requires less connected horsepower, peak-hours electrical demand can be lowered by 50 percent or more. Additionally, chillers are inefficient when run at low loads, and during spring and fall – about half the year – they typically operate at about one-third capacity. Smaller ice system chillers are operated at full load, maximizing their efficiency.
Other beneficial factors in favor of ice thermal storage are ease of maintenance due to lack of moving parts and smaller chillers, pumps and other equipment, as well as increased system reliability. Ice storage systems typically utilize two chillers that provide about sixty percent of the required cooling each day, with the stored ice providing the remaining forty percent. In the event one chiller fails, seventy percent of the usual cooling capacity will still be available, as opposed to a maximum of fifty percent from a traditional two-chiller system when one of them fails.
For more information on how ice thermal storage systems can help you save money and energy while reducing your carbon emissions, please contact MSC at 973-884-5000.