TES hvac systems
Thermal Energy Storage (TES) System, or ice banking, is a technology which shifts electric load to off-peak hours, which will not only significantly lower energy and demand charges during the air conditioning season, but can also lower total energy usage (kWh) as well.
When demand for electricity is low (at night) and less expensive to purchase, conventional chillers or industrial-grade ice-making units produce and store cold water or ice. This stored coolness is then used for space conditioning during hot afternoon hours, using only circulating pumps and fan energy in the process.
Thermal energy storage (TES) systems chill storage media such as water, ice, or phase-change materials. Operating strategies are generally classified as either full storage or partial storage, referring to the amount of cooling load transferred from on peak to off-peak.
TES systems are applicable in most commercial and industrial facilities, but certain criteria must be met for economic feasibility. Capital costs of TES depend on the economy of scales. If carefully designed for new facility significant first cost operating benefits could be achieved.
A TES system can be appropriate when
- Maximum cooling load significantly higher than average load
- High demand charges, and a significant differential between on-peak and off-peak rates
- Appropriate where chiller capacity is needed for an existing system, or where back-up or redundant cooling capacity is desirable or where electrical infrastructure is inadequate to match demands
TES systems may also reduce energy consumption, depending on site-specific design, notably where chillers can be operated at full load during the night. Favorable nighttime operation and lowering the chilled water temperatures and cold air distribution can achieve significant savings achieved in pumps and fans operations. Number of other design options can make TES systems more energy efficient than non-storage systems.