Data Center Water-Savings Win Wins

NREL and partners honored with Federal Energy and Water Management Award for resourceful data center cooling

Aug. 23, 2018

High-performance computing (HPC) produces a lot of heat. The HPC data center cooling system at NREL’s Energy Systems Integration Facility (ESIF) was designed to be super effective in managing that heat—using evaporative towers that are more efficient and less expensive than energy-demanding chillers. But the towers consumed approximately 2.5 million gallons of water annually to support cooling of the IT load—approaching an hourly average of 1 megawatt. Driven by a mission to push the leading edge for data center sustainability, NREL recognized the need to make the data center not just energy efficient, but water efficient, too.

So, thanks to NREL’s David Sickinger, Roy Fraley, and Kevin Regimbal, along with partners from Johnson Controls and Sandia National Laboratories, the BlueStream Hybrid Cooling System was born on the roof of the ESIF in August 2016. It saved 1.16 million gallons of water in its first year of operation, cutting the data center’s onsite water usage in half while continuing to operate at optimal energy efficiency. In combination with the existing evaporative towers, this advanced dry cooler that uses refrigerant in a passive cycle to dissipate heat—called a thermosyphon—forms an extremely water- and cost-efficient hybrid cooling system.

And the project's success did not go unnoticed: this year, NREL engineers David Sickinger and Kevin Regimbal received U.S. Department of Energy (DOE) Federal Energy and Water Management Awards for this outstanding achievement in energy and water efficiency and conservation. Annually, these Federal Energy Management Program (FEMP) awards recognize individuals and organizations who have made significant contributions to energy and water efficiency within the federal government. Tom Carter of Johnson Controls, David Martinez of Sandia, and DOE’s Matt Graham were also honored for their contributions to the project. The team will receive their awards at a ceremony in Washington, D.C., in October.

The idea to implement the hybrid thermosyphon cooling system at NREL came through the outreach of Tom Carter from Johnson Controls, which had been working with DOE's FEMP to find a location to implement its new thermosyphon technology. The technology has potential application in data centers around the world and is currently being implemented by Sandia.

As detailed in the report Thermosyphon Cooler Hybrid System for Water Savings in an Energy-Efficient HPC Data Center: Modeling and Installation, integration of the thermosyphon cooler into the existing energy recovery water loop required only a one-day outage to NREL’s 10,000-square-foot HPC data center. Often called the most energy efficient data center in the world, NREL’s data center has achieved a trailing 12-month average power usage effectiveness (PUE) of 1.04. It features a chiller-less design, component-level warm water liquid cooling, and waste heat capture and re-use. That, in addition to formidable computing power, which will soon be boosted more than threefold with NREL’s newly acquired 8-petaflop supercomputer, Eagle.   

Stay tuned for more on the thermosyphon: NREL plans to release a report next month detailing 24 full months of operation. 

Learn more about NREL’s energy- and water-efficient HPC data center.