University of New Hampshire
IN-49: Innovation C

UNH has spent the past year constructing an innovtive new addition to our district energy system; a chilled water thermal energy storage (TES) tank in the heart of campus. This 1.4 million gallon, $x tank will serve as a critical piece of infrastructure for providing cooling to campus facilities and reducing our peak electrical demand. It designed to store 10,000 ton-hours of cooling energy and have the ability to discharge in 4 hours. In electrical energy terms, this is roughly equivalent to a 15,000 kWh battery and could decrease demand by up to 3,750 kW.

The TES tank is a solution to the cooling challenges that we are facing. Instead of installing a new chiller plant to produce energy for cooling, the TES tank can store chilled water produced by the existing chiller plants during off-peak nighttime hours, when it is cheaper and more efficient to cool water. UNH's current energy system relies on landfill gas, which is a renewable fuel source. Since there is less energy demand at night, UNH is able to cool water using only this renewable fuel. There is more chilled water produced at night than we need, so the excess is stored in the TES tank. The water can then be released for use in air conditioning during the day, when the demand is high. This decreases the amount of additional energy that must be purchased to meet demand during peak hours. Using stored energy reduces cost and decreases dependence on non-renewable energy sources.

The tank was a large investment but the projected payback period is under five years. This infrastructure can ultimately be tied into a geothermal system, which gives UNH important optionality as it pursues ambitous decarbonization goals, And, because the tank is very large and very centrally located, it is a powerful platform for engagement and education for the entire camppus community about energy, efficiency, and climate solutions.

https://www.unh.edu/unhtoday/2019/08/nasa-lands-unh