How a California courthouse saved energy and money with CALMAC’s IceBank energy storage system
Outdated plumbing, an inefficient HVAC system, old wiring—like many courthouses across America, the Kings County Courthouse in Hanford, California, was an antiquated hodgepodge of buildings. While renovation was imminent, the decision-makers chose to take the project a few steps further, seeking LEED Silver certification that included upgrades like thermal energy storage tanks.
“Those buildings were reaching their life cycle end in terms of the mechanical system as well as parts of the building,” says Paul Valenta, vice president of sales and marketing for CALMAC, adding that building owners wanted a usable complex that was sustainable, too. “The biggest bang for your buck in terms of gaining LEED points is in energy costs.”
CALMAC’s IceBank energy storage system gave the courthouse operational flexibility to store energy during off-peak hours that could then be used on hot summer days. Ultimately CALMAC was able to reduce the facility’s energy costs by 26%, or a savings of $102,000 annually. The courthouse was LEED Silver certified in 2017.
“Ice-based thermal energy storage systems are a great solution for customers with energy reduction goals because they also provide proven reliability and lower operating costs,” Valenta says. “Applying thermal energy storage as part of the design at the Kings County Courthouse was crucial. In California, energy costs vary based on peak and non-peak times of the day. Shifting the load to times when energy is less expensive reduces energy use and saves the county and its taxpayers considerable costs.”
How They Do It
To save money on energy costs, the CALMAC system makes ice at night, when energy rates are lowest, and the building uses the ice to cool the building during the day. “Nighttime energy is used to create cooling that will be used during peak times. To start the cooling day, typically, the right-sized electric chiller will cool the load first. As the load increases above the chiller capacity or a peak time occurs, the stored cooling is discharged to augment the right-sized chiller.”
CALMAC ice storage tanks are integrated with Trane commercial HVAC systems to take pressure off of the energy grid. The ice storage tanks store energy, similar to a battery, to be used when needed. This reduces the strain on public utilities, lessens operating costs for building owners, and allows for better use of renewable energy.
CALMAC builds the Ice Bank thermal energy storage tank and ships it to you, ready to go. The tank is made of a single seamless piece of high-density polyethylene for containment and structure—nothing can rust or corrode. “It’s the same material used to distribute natural gas throughout the U.S.,” Valenta says. “That’s going to last 30 or 40 years. The ice tank will probably outlive that right-sized chiller. Instead of replacing a 100-ton chiller in a conventional cooling system, the thermal energy storage system requires a smaller replacement.” Typically a building requires 100 tons of cooling, but CALMAC has “right-sized” that need to 60 tons, with the other 40 to come from the thermal energy storage tanks.
The IceBank tanks are modular, so you can add more tanks over time and relocate them easily. CALMAC also provides a limited five-year parts warranty on internal workings and a 10-year limited parts warranty on the tank vessel. But the tanks are resilient. If the chiller ever stops working or a power outage occurs, the standby generator will power the pump and keep the building cool.
Add to that the question of reliability around renewals—you have to have the sun or wind to have energy, right? “If I’m removing that coal or that energy storage, how do I bring it back into the grid so my grid can be a reliable utility?” Valenta says.
Many states are working to set mandatory energy storage targets, according to the Energy Storage Association. “No matter what this administration does, coal is going away,” Valenta sways. “The reliability of the grid is a big issue, and that’s where we fit in.”
A Sustainable Story
CALMAC has been part of Trane since late 2017, but the company itself has a long history of sustainability and leadership, having started in 1947. “I call us the Porsche of HVAC because research is a big part of what we did even then. And sustainability was a big part of that,” Valenta says.
He recalls seeing old videos from when the company’s owner, Mark MacCracken, was just a boy helping his dad as part of the first photovoltaic conference in Phoenix. “His dad was always into solar and always inventing. In fact, when I was hired, I never saw him [founder Calvin MacCracken] in his office. He was back in his lab.”
Efficiency has always been part of the CALMAC story. “For the past 30 years we’ve focused on energy storage, and within the last 25 years of that we’ve had a great relationship with Trane, with our goal of making comfort cooling less impactful on the environment,” Valenta says.
CALMAC has also eliminated ABS and PVC materials, gluing agents, and all internal mechanical fittings in the construction of IceBank tanks. Tanks are 99% reusable or recyclable, and the manufacturing facility in New Jersey is LEED Gold–certified.
Project: Superior Court of California Kings County
Location: Hanford, California
Problem: Energy storage
Solution: CALMAC's IceBank
Savings: 26% energy costs reduction or $102,000 annually
Architect: DLR Group
Structural Engineer: Buehler & Buehler