Data centers are the bricks and mortar of the internet. These buildings store servers, digital storage equipment, and network infrastructure for the large-scale data processing and storage. Our increasingly digital world has an ever-growing need for data creation, processing, and storage from businesses, online platforms, video streaming, smart and connected infrastructure, autonomous and driver assist vehicles, and artificial intelligence. The amount of data created and stored globally is expected to reach 175 Zettabytes by 2025, representing nearly a six-fold increase from 2018. The role of data centers in storing, managing, and distributing data has remained largely out of. Similarly, the environmental implications of data centers have been obscured from public view.
The United States houses nearly 30% of data center servers,
more than any other country; and northern Virginia houses more data centers than
any other locality. In a study recently published in Environmental Research Letters, Landon Marston,
an assistant professor at Virginia Tech and colleagues looked at how and where
data centers consume energy and water in the United States. The results showed
that it takes a large amount of water to support the internet and cloud service
and that the water often comes from water-stressed basins. Physical location of
data centers impacts the carbon and water footprint. Below are excerpts from their study “The
environmental footprint of data centers in the United States”
Citation Md Abu Bakar Siddik et al 2021 Environ.Res. Lett. 16 064017DOI 10.1088/1748-9326/abfba1
Though the amount of data center computing workloads has increased nearly 550% between 2010 and 2018, data center electricity consumption has only risen by 6% in that time due to dramatic improvements in energy efficiency and storage-drive density across the industry. However, the water and greenhouse gas footprint of the data center industry is huge. In addition, it is unclear whether energy efficiency improvements can continue to offset the energy demand of data centers as the industry is expected to continue its rapid expansion over the next decade.
In this study, Drs Marston et al used the records of data
center operations to provide the first regional estimates of data center water
and carbon footprints. The water footprint is defined as the consumptive blue
water use (i.e. surface water and groundwater). The greenhouse gas footprint of
a data center, expressed as equivalent CO2, is used to represent its global
warming potential. The scientists looked at the operational environmental
footprint of data centers which includes the power plants, water supplier, and
wastewater treatment plant servicing the data centers.
Power plant-specific electricity generation and water
consumption data come from the US Energy Information Administration (EIA). The
U.S. Environmental Protection Agency's eGRID database provided GHG emissions
associated with each power plant.
The indirect water and carbon footprint of each data center
consists of water consumption or GHG emissions associated with the generation
of (i) electricity utilized during data center operation, (ii) electricity used
by water treatment plants for treatment and supply of cooling water to data
centers, and (iii) electricity used by wastewater treatment plants to treat the
wastewater generated by a data center.
Direct water consumption of a data center is based on heat
generation related to the amount of electricity used. Estimates of data center
specific electricity demand were multiplied by the typical water cooling
requirement—1.8 m3 per MWh—to estimate the direct water footprint of each data
center. Data center wastewater is largely comprised of blowdown; the
portion of cooling water removed from circulation and replaced with freshwater
to prevent excessive concentration of undesirable components. In general data
centers recycle their water until the concentration of dissolved solids (which
is essentially salts) is roughly five times the supplied water.
Since water stress is expected to increase in many
watersheds due to increases in water demands and more intense, prolonged
droughts due to climate change. For these reasons, environmental considerations
may warrant attention alongside typical infrastructure, regulatory, workforce,
customer/client proximity, economic, and tax considerations when locating new
data centers. However, placing all new data centers within a small area may
strain local energy and water infrastructure due to their collective water and
energy demands. The scientists suggest that data centers can be dispersed more
broadly in areas that are favorable with respect to water footprint, water
scarcity, or carbon footprint. As seen in the diagram below shows that seems to
indicate that parts of the northeast and southern Florida are the best locations
for data centers to minimize GHG and water impacts.
from Marston et al |
The scientists also suggest the data center industry can make investments in solar and wind energy. Directly connecting data center facilities to wind and solar energy sources ensures that water and carbon footprints are minimized. However, data centers require level power supply and renewable sources are variable. Purchasing renewable energy certificates from electricity providers does not necessarily reduce the water or carbon footprints of a data center. However, these investments gradually shift the electrical grid toward more renewable energy sources, lowering the overall GHG impact for all energy users.
Overall, the scientists show that strategically locating new
data centers can significantly reduce their environmental footprint. Climatic
factors can make some areas more favorable due to lower ambient temperatures,
thereby reducing cooling requirements. Lower cooling requirements reduces both
direct and indirect water consumption, as well as GHG emissions, associated
with data center operation. Since most data centers meet their electricity
demands from the grid, the composition of power plants supplying electricity to
a data center plays a significant role in a data center's environmental
footprint. The scientist show that real estate decisions may be as important as
technological advances in reducing the environmental footprint of data centers.