“Data centers get a lot of bad press,” Ed Ansett, global director of data center technology and innovation at engineering consultancy Ramboll. That’s largely because they’re fundamentally unsustainable, consuming vast amounts of energy and water; they’re also highly carbon-intensive.
But there are ways data centers can lessen their impact, according to Ansett, whose white paper “Developing sustainable data centres” was published this week by Ramboll.
One way, of course, is simply cutting a data center’s operational carbon, i.e. the emissions produced by a data center through its operational life, and essentially its energy use. For all but the still-rare off-grid data center, bringing down operational carbon depends on the emissions factor of the grid supplying power; a utility grid with more renewables will lead to a lower footprint than one that relies heavily on coal.
Still, data centers have options, including signing renewable power purchase agreements and implementing energy export and efficiency measures. And for developers scouting where to locate a data center, prioritizing sections of the grid with low emissions is key — and something that might be easier for AI data centers performing tasks that are less sensitive to latency and can be more flexible on location.
(While not to be dismissed, carbon offsets should only “be used as a last resort,” Ansett told Latitude Media.)
Energy export measures include providing “grid balancing services, or, in other words, exporting energy to the grid, which helps a country [or energy system] reduce marginal carbon emissions,” Ansett said. That can provide an alternative to relying on peaker plants during high demand.
These services are ways for data centers to achieve load flexibility and potentially reduce their energy demand in times of grid stress. Hyperscalers and others in the industry have only recently started exploring load flexibility, but it has already become one of the hottest topics of conversation in the market for the past six months.
Heat recycling is another avenue for sustainability. “Heat is a data center’s only actual physical byproduct, and it’s typically just discharged,” said Ansett. “But it’s possible to take that heat, export it, and use it for heating of homes, or other types of heat off-takers, like manufacturing facilities.”
Data center developer Equinix, for example, has been doing so for over a decade. And in Germany, a 2023 law mandated that data centers starting operations from July 2026 onwards must have a 10% share of reused energy, including waste heat, a share that will increase to 20% in 2028.
This ties to circularity, a concept Ansett said “the data center industry needs to get to grips with.” It includes reutilizing heat and water, as in closed-loop liquid cooling systems, but also recovering valuable metals in electronic equipment: gold, silver, platinum, tantalum, lithium, cobalt, copper, and nickel.
“Almost everything in a data center can be recycled or reused, but in order to make that happen, we need to design systems so that they can be taken apart, recycled, and reused,” he added.
Other areas identified in the report include biodiversity — through conservation-sensitive practices — water efficiency, and embodied carbon, or the emissions from construction. Embodied carbon is particularly high in data centers due to their concentration of mechanical, engineering, and plumbing systems. (Also this week, low-carbon cement manufacturer Fortera announced an investment from Microsoft.)
Certain hyperscalers and developers worldwide are already investing and experimenting in these areas. Data centers in parts of Northern Europe where grid emissions are low — including Denmark, Finland, Iceland, Norway, and Sweden — are doing particularly well, according to Ansett.
“[But] how do they balance their sustainability efforts against cost? Some of these things we’re asking for cost money, and you may have to pay more for a product to make it sustainable,” Ansett said. “For everyone we deal with, sustainability is a key topic. What I’m not sure of is how important it is in the context of the overall [balance sheet]. I suspect that’s one of the key issues.”
A version of this story was published in the AI-Energy Nexus newsletter on September 24. Subscribe to get pieces like this — plus expert analysis, original reporting, and curated resources — in your inbox every Wednesday.
