Thermal energy storage is an add-on / enhancement for a building’s HVAC cooling systems. A thermal energy storage system is a large tank of water and glycol solutions that are frozen at night when energy is cheaper.
The idea behind thermal energy storage is that it off-sets the coincident peak that utilities see during the summer from HVAC electric demand. In a sense, a thermal energy system acts as a battery for a building’s HVAC unit.
A thermal energy storage system utilizes the compressors in chillers, or RTUS, to cool a huge block of ice at night. Night time, when the building is using the least amount of energy, is known as “off-peak hours.” This is a time when energy uses are at a minimum allowing for the most efficient and cheapest cooling periods in a day.
As warm summer days begin to heat up, the ice melts and the cool vapors are used to cool the building instead of traditional HVAC system compressors. For a better understanding of thermal energy systems and how they work, what the video below.
There are many benefits to implementing thermal energy storage. One is that it allows businesses to eliminate their entire HVAC coincident peak load.
Also, many utilities will incentivize the adoption of thermal energy storage with special rates and recognize the reduced peak demand, and can payback as quick as 2-3 years. Reducing stress on the electric grid during hot summer days is another key benefit. Lastly, thermal energy storage helps increase the useful life of an HVAC system, since it requires little to no usage on warm days when it typically works continuously to keep your building cool.
Similar to thermal energy, batteries store energy and discharge the energy throughout the day. Commercial battery storage allows your building to store electricity from an electric grid or a renewable energy source.
Energy storage allows facilities to store energy with maximum usage during off-peak hours, and discharge the energy throughout the day; this allows for the most efficient usage of your HVAC system and also assists in peak demand management.
If a system at a facility is charged with renewable energy, the batteries can qualify for the Renewable Energy Investment Tax Credit (ITC). Batteries can also significantly increase project paybacks with utilities that charge high amounts for electric demand.