Plant Operators Learn New Skills to Transition to Hot Water, Geo-Exchange System

A major component of achieving net-zero carbon emissions by 2046 is the transition from the current steam heating system to a district hot water system that incorporates geo-exchange.

Many things must happen for this epic conversion project. New infrastructure is being laid in the form of pipes and bore holes, facilities are coming online that house the utility equipment, and HVAC systems are being installed and converted.

Across these elements, the team running the system must learn the new operations.

“It is like getting a new car,” Ted Borer, Energy Plant Director said. “Everyone in the plant knows how to drive a car, but they must learn this model’s specifics—the turning radius, the maintenance schedule, and just how much pressure the pedal needs.”

More than a year and a half ago, long before the TIGER came online, the 30 plus engineers, control operators, technicians and apprentices began to train on the new system. They must learn new equipment and how the new system operates.

“We’re used to running chillers with condensers to a tower,” Eric Wachtman, Chief Engineer said. “Now we’re moving hot water around in many different directions.”

Electric heat pumps are the essential piece of equipment for moving the water around campus at the appropriate temperatures. The new system involves many of the same principles of the one it is replacing — the new heat pumps even look like the old chillers — but now the plant can harness the heat that was once sent out through the towers, store it, and utilize it when needed. The extra energy gets stored in the ground through the geo-exchange bores or in large water tanks called thermal energy storage tanks.

Learning the system is facilitated by formal training sessions and on-the-floor engagement with the operators. Since the new system will come online over time as buildings are finished or converted, the team is able to figure out the system’s abilities while the load is lighter.

“This is going to be an ongoing process of figuring out how much we can store and extract later,” said Art Shadell, Relief Senior Shift Operator. “That will be one of the biggest things we learn as a group, as we go.”

To help with that learning, the plant hired David Weis, a controls engineer expert, in late 2022. Weis specializes in the fine-tune refinements needed to optimize the system. He works closely with the operators to understand and troubleshoot how things should work together.

“Dave is part of the team and has been hugely instrumental in teaching us,” Wachtman said. “His involvement in and understanding of hydraulics of this system is key for training our operators.”

The plants are complex and ever evolving to meet campus needs. The team’s success at navigating such growth is a product of the culture of learning and teamwork that Wachtman and others have cultivated at the plant, which is staffed 24/7, 365 days a year.

“Princeton is constantly upgrading and changing,” said Gary Pepek, Senior Shift Operator. “We’re always getting educated on something.”

“You’ll never come in here and say, ‘I know it all’,” adds Brian Glendon, Lead Utility Plant Engineer. “As soon as you think you do, something’s going to change. Or you’ll come across something — it may take 30 years — that you had never come across before.”

The entire plant staff, from seasoned veteran to new apprentice, is working together to problem solve in real time and put into practice the principals from the training classes. They are doing it all while running and maintaining the old system, which will remain in place until roughly 2035.

“I am proud of our team,” Wachtman said. “Everybody learns differently and at a different pace. We are all working together to understand, operate and maintain the new plant. We share the successes.”