Though not insignificant, data center water efficiency is often overlooked when optimizing data center operations. Water consumption is typically associated with meeting cooling needs, emphasizing the importance that energy efficiency actions can have not only on reducing energy consumption, but also water consumption.
Overview
Often overlooked, data centers consume not only energy, but also water. Direct water consumption in data centers can generally be attributed to meeting cooling requirements, while indirect consumption may occur as a result of electricity generation to power a data center. As such, ensuring that efficiency is viewed holistically - from the IT equipment, to the cooling required to maintain a hospitable environment for equipment is paramount.
While data center water consumption may not be a core focus for operators, it is non-trivial, with U.S. data centers estimated to consume over 400 million gallons per day (Nature, 2018). It is estimated that less than a third of data center owners and operators in the U.S. measure and track water consumption. Metrics such as water usage effectiveness, or WUE have emerged to enable assessment of water efficiency performance relative to other data centers.
High-Level Best Practices
Key best practices for water efficiency in data centers include:
- Implement metering/monitoring systems to track water consumption
- Raise the chilled water temperature
- Evaluate chillers for replacement
- Explore opportunities to reduce cooling needs through air mangement strategie, IT efficiency upgrades, and power improvements
Featured Resources
FEMP Water Efficiency in Federal Buildings & Campuses Webpage
The Federal Energy Management Program (FEMP) provides agencies with guidance and direction on how to increase water efficiency and reduce water use in federal buildings and campuses. Explore resources including trainings, tools, and more geared to assist in efficient water management planning, measurement, optimization, and expansion. Access the webpage.
FEMP Best Management Practice: Cooling Tower Management
Cooling towers dissipate heat from recirculating water used to cool chillers, air conditioners, or other process equipment to the ambient air. Heat is rejected to the environment from cooling towers through the process of evaporation. Therefore, by design, cooling towers use significant amounts of water. Resources on cooling tower operation and maintenance, retrofit and replacement options, and more. Access the webpage.
Data Centre Water Consumption
This paper examines the water consumption of data centers, the measurement of that consumption, highlights the lack of data available to assess water efficiency, and discusses where the industry is going to reduce future consumption. Access the article.
Making a Splash: Targeting Water Saving Measures for the Highest Impact (PDF)
Slides from NREL's presentation at the 2018 Better Buildings Summit Energy Exchange on designing and building the world's most efficient data center, with a focus on water savings. Access the slide deck.
Thermosyphon Cooler Hybrid System for Water Savings in an Energy Efficient HPC Data Center: Modeling and Installation
The Thermosyphon Cooler Hybrid System (TCHS) integrates the control of a dry heat rejection device, the thermosyphon cooler (TSC), with an open cooling tower. Johnson Controls partnered with two national laboratories—the National Renewable Energy Laboratory (NREL) in Golden, Colorado, and Sandia National Laboratories in Albuquerque, New Mexico—to deploy the TSC as a test bed at NREL’s high-performance computing (HPC) data center in the first half of 2016. Explore the project.