1.8.2 Thermal Energy Storage
Reduce peak demand of energy by shifting electricity use to off-peak periods.
Components include thermal storage tank (ice-on-coil), a packaged chiller or built-up refrigeration system and interconnecting piping, pumps and controls. The storage medium is generally water, ice or a phase-change material. Basements or roof top levels are preferred locations. The latter are less energy efficient, due to higher ambient temperatures.
A thermal energy storage (TES) system produces ice at night when electricity rates are lowest to reduce peak daytime demand loads on the grid. Ice is made at night in non-corrodible tanks and used the following day to cool/air-condition buildings. TES increases the energy efficiency of cooling and reduces associated operational costs through a cooling mechanism that requires early coordination with system engineers.
Reduces initial cost and consumer’s operational cost. Raw fuel savings of 8 to 34 percent when comparing on and off-peak operation (California Energy Commission). Operation is generally at night when lower ambient temperatures make for cooler condenser temperatures, reducing energy use.
TES provides operational flexibility. TES reduces peak demand (20-40%) at critical periods, first cost (up to 10%), consumer’s energy cost (10-20%), energy usage at the building (up to 14%), source energy usage at the power plant (8-34%), emissions (up to 50%). (Source: M. MacCracken, “Ice Thermal Storage and LEED Gold”, CALMAC Mfg. Corp., http://intraweb.stockton.edu/eyos/energy_studies/content/docs/FINAL_PAPE...)
Cool storage systems are most suitable where any of the following criteria apply: the maximum cooling load of the facility is significantly higher than the average load. The electric utility rate structure includes high demand charges. Electric power available at the site is limited. Backup or redundant cooling capacity is desirable. An existing cooling system is being expanded.
1.4.8 Solar Hot Water Collectors
1.6.3 Ground/ Water Source
1.7.9 Active Solar Heating