MCLB Albany to receive new ground source heat pump

In keeping with the Department of Defense’s initiative to become Net Zero by 2020, Marine Corps Logistics Base Albany continues to seek new opportunities to reduce its energy consumption through alternative sources.

One source identified is the Borehole Thermal Energy Storage System, a state-of-the-art ground source heat pump system for heating and cooling, according to Lt. Cmdr. Dennis Riordan, public works officer, Installation and Environment Division, MCLB Albany.

“The project costs $5 million and is the first of its kind in the U.S.,” Riordan said. “BTES will reduce Building 3700’s electricity bill by 30 percent.”

During the summer, warm water is stored on outskirt of the system’s concentric circle and cold water is pulled through the air conditioning from the center of its circle to cool the building. In the winter, cold water is stored and warmer water is pulled through the heater to heat the building.

“During the summer, when it is 100 degrees outside, we will be running 70-degree water from the ground through the building, which is about the same temperature you would (find) with conventional air conditioning to keep your room at 70 degrees,” Riordan said. “The only power required is for the pump to pump the water.”

BTES will take heat from the building and put it back into the ground and store it there for use as building heat during the next winter cycle.

 “Net Zero is the point in time when MCLB Albany generates as much electrical energy from renewable resources as the base consumes,” Riordan said. “Building 3700’s BTES system will reduce the overall electrical power consumption of the entire base by approximately 2 percent with an additional natural gas savings of 20 percent. 

“BTES differs from more ‘conventional’ GSHP systems used in the United States as it is designed to store the precise amount of heated or cooled water in the ground for energy and use in the future,” he added.

Riordan described BTES like a radiator in a car, which circulates water and does not leave the system.

“BTES is a closed-loop system, which means the chilled water in the building never touches the drinking water,” Riordan said. “There is no potential for contamination.”

BTES system is typically laid out in concentric circles and zones to deliberately store the primary thermal entity needed, hot or cold, he stated.

Workers will drill 306 wells with a depth of 225 feet each using a high density polyethylene tube to circulate water for energy transfer.

The system is made up of five modular heat recovery geothermal heat pumps, which will be placed inside Building 3700’s mechanical room and two adiabatic dry-coolers will be stationed near the well field.

In addition, the new system is much more reliable than the current system, according to Riordan.

“(BTES) will not be exposed to the sun so there will not be ultraviolet damage,” he said. “Whereas, the current chiller system (we have now) fails at least once a year and we have to put a lot of money into it for corrective maintenance.

Mike Henderson, supervisor, Public Works, I & E Div., MCLB Albany, said the base is sitting on top of land that can be used to store energy, a thermal energy storage with a constant temperature of 70 degrees.

Construction for the new system recently began with the clearing of a two-acre area behind Building 3700, home of Marine Corps Logistics Command headquarters staff of more than 800 personnel.

The project is scheduled to be completed by April 2015, in time for LOGCOM employees to use before the South Georgia summer heat begins.  

Henderson estimates the base will recoup the project’s expense in 15 years.

The project is a joint venture by the Department of Energy and DoD.

The BTES design was funded by the DoD Energy Conservation Investment Program while the design cost was funded by DoE as a “demonstration project,” Henderson added. 

The project is one part of MCLB Albany’s aggressive overall energy conservation plan to meet all federal energy conservation mandates, goals and objectives by 2020. 

“The base has reduced overall energy by approximately 35 percent, at a savings of $4 million per year, with plans to be energy Net Zero by 2017,” Henderson said.