The world’s infrastructure is becoming more electric, driven by technology and the need for more sustainable solutions. In the electrified world, data centers are relied upon to support mission critical systems every day, and to do so while adopting more environmentally sustainable practices.
As the data center industry develops and managers implement innovative new approaches that drive energy efficiency, taking action to reduce environmental impact often also leads to cost savings. Regulatory and customer pressures also make it imperative for data center managers to consider overall environmental impact. Here are several areas where data center managers can focus on operating in a more environmentally sustainable way:
Power Usage Effectiveness (PUE)
PUE describes how much of the energy that comes into a data center facility is used to power IT equipment. Equipment with lower PUE allows data centers to use less energy on things like facility operations and cooling. While data centers do not have much control over the power demands of the IT equipment they house, data center managers can make sure their cooling systems are as efficient as possible—liquid cooling, for instance, has very good PUE. Some liquid cooling systems can significantly reduce a data center’s PUE below the industry average of 1.59.
Water Usage Effectiveness (WUE)
Data center managers need to remain aware of water quality and WUE when deciding how to cool a data center. While data center liquid cooling systems require clean, treated water to run at optimized operational efficiency, in closed loop water-cooled systems, the same water is circulated through a chiller to be cooled and recirculated, leading to lower overall water use.
Counterintuitively, air-cooled data centers can often end up consuming more water than liquid-cooled data centers. Water is used in evaporative cooling air conditioning systems in these facilities, with cold water running into the facility to cool the air and warm water running out. In these air-cooled facilities, cooling liquid used in air conditioning needs to be very cold to cool air to the necessary temperatures for equipment operation. The evaporation that results from warm water hitting freezing cold chilling coils can result in increased water consumption as water must be constantly replaced in the system. This can cause problems not only for the data center, but also for the municipal regions where they are located by putting added demand onto public water systems.
Evaporative coolers have other drawbacks as well, such as their tendency to corrode over time, bringing increased cost and material use. As a more environmentally-friendly alternative, data centers can use warm water cooling or immersion cooling to limit water loss in water-stressed parts of the world or places where regulations place pressure on or limit water use.
Physical Space
The use of physical space impacts data center sustainability and cost. Rising demand for internet and cloud services requires high volumes of advanced IT equipment. But data center operators usually can’t expand buildings at the same rate they need to expand capacity. Additionally, taking up more physical space is not a sustainable practice. Upgrading cooling systems can help solve this problem. With more advanced cooling solutions, data center operators can increase equipment density without increasing building size.
Coolant Fluid
There are two main kinds of immersion cooling fluids: hydrocarbon base fluids and fluorocarbon base fluids. Both have benefits and drawbacks. Hydrocarbon liquids do not evaporate, which means they do not have to be replaced and refilled very often. They also have a low global-warming potential (GWP), meaning that evaporated hydrocarbons do not remain in the atmosphere for very long. However, hydrocarbon liquids are very oily, so they can be messy for data center staff to handle and the refinement process is not very environmentally friendly.
Fluorocarbon liquids, on the other hand, behave more like alcohol than oil—they evaporate more easily and therefore need to be refilled more frequently. However, they are easier to work with and less messy to handle. Data center managers need to look at their immersion coolant choices in the context of the rest of their operations to determine the path that is the most environmentally sustainable and most appropriate for their cooling needs.
Alternative Energy Sources
Even the most well-designed data centers use a lot of energy, but large data centers can offset their carbon footprints by installing on-site renewable energy such as rooftop solar panels. This can also contribute to lower energy costs. One sustainable choice often leads to another—for instance, moving away from evaporative coolers located on data center rooftops could also free up space for rooftop solar installations.
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