Dean Nelson
I Started infrastructure Masons (iMasons) in 2016 to unite the builders of the digital age. How to define digital infrastructure is an ongoing discussion, as are questions about the size of the digital infrastructure industry. The answers to these questions are essential to answer one more: What is the industry’s carbon footprint? The answer to that question will serve as a baseline for the iMasons Climate Accord, which launched on 25 April 2022, and commits member companies to achieve carbon neutrality in power, materials, and products as a step toward net zero. To measure our industry’s carbon footprint, we need to define two things: what to measure and how to measure it.
Today, more than 200 member companies have joined the iMasons Climate Accord. Yet, a clear, definitive measure of the digital infrastructure industry’s carbon footprint remains elusive. In addition to reaching a consensus on the definition of digital infrastructure, we need a standardized methodology to quantify the carbon embodied in digital infrastructure and the carbon intensity associated with the energy consumed to operate it.
The push to define our industry started to gather momentum back on Earth Day in 2020 when iMasons published its sustainability vision to ensure that “every click improves the future” (see Figure 1). To me, this vision means that digital infrastructure should contribute to the global economy and society without harming the planet. Today, the construction and operation of digital infrastructure emits carbon dioxide and other greenhouse gases that cause global climate change. To contribute to the global economy and society without harming the planet, we need to neutralize this carbon footprint.
Figure 1. Illustrated discussion between hyperscale and Colo executives during iMasons Sustainability Vision launch on Earth Day, 2020.
In July 2021, frustrated at the lack of progress in defining our industry, I engaged the chair of the iMasons Sustainability Committee, and other experts, on a six-month journey of conversations and meetings with our members around the world to develop and propose a formal definition of digital infrastructure.
We agreed that iMasons’ members represent the majority of global data centers portfolios that deliver digital services across the world. In other words, our membership enable the foundation of today’s Internet and digital economy: the portfolio of services that are delivered, consumed, and managed through digital technologies, from cloud storage and website hosting, to content streaming, text messaging, and blockchain ledgers.
Although hyperscale data center facilities account for more than half the consumption of these digital services worldwide, we expanded our aperture to include all the elements that make up the infrastructure that delivers digital services, including the IT equipment that processes and stores data, the facilities that house that equipment, and the networks that connect them all. This expanded aperture led to our first definition: digital infrastructure is a collection of data center locations that deliver electronic services to people and machines.
We next defined data centers as real estate locations that house IT equipment to process, store, and transmit data. Finally, to establish the global baseline and track progress in carbon reduction across our industry, we classified data centers into three categories: providers, networks, and crypto.
Providers are data centers that deliver electronic services to themselves, others, or both. This includes hyperscale, enterprise, colocation and edge data centers, which are widely agreed upon throughout our industry to represent digital infrastructure.
Networks include data centers that operate as fixed and mobile networks as well as carrier hotels and Internet exchanges. Carrier hotels are buildings that house networks and cloud services and are strategically located in the center of a downtown area to reduce latency. Internet exchanges are physical locations where Internet infrastructure companies such as Internet service providers and content delivery networks exchange Internet traffic. Some members of our organization argued that carrier hotels and Internet exchanges are usually intermingled with enterprise, colocation, and hyperscale data centers, and thus not distinct. Our committee argued that a real estate location can have a unique address and house multiple tenants. The key for our measuring stick is to account for the carbon footprint of each tenant, be they a provider or network.
Crypto includes all crypto mining and blockchain services. This is the newest category of data center classification and the biggest source of controversy among our members. For example, one argument holds that crypto deployments lack the built-in resiliency found in traditional data centers such as backup generators and uninterruptible power supply systems, which provide redundancy and protection from power disruptions and thus don’t qualify as data centers. Our committee holds that crypto mining and blockchain service providers deliver electronic services to people and machines just like providers and networks. We made crypto a standalone category due to its unique design, consumption and projected growth; all of which have significant impact on overall carbon accounting for our industry.
We then turned our attention to calculating a global estimate of data centers worldwide. Although hyperscale cloud providers maintain detailed records on their own capacity, information on the total number of data centers is fluid. As hyperscalers gain market share, industry analysts note that the number of traditional data centers has halved while the industry has gigawatts of planned capacity in the pipeline.
To arrive at a clearer picture, we consulted with the data and market research firm Statista. Based on the firm’s surveys, there were 7 million data centers that fit our definition of digital infrastructure in 2021. Each of these data centers has a unique address and they range in size from hyperscale data centers with more than 1 GW of power capacity, to microedge deployments on street corners that draw less than 1 kW of power. In total, they represent 105 GW of power capacity and, in 2021, consumed a total of 594 TWh of energy. This consumption equated to 2.4% of global energy consumption that year, which was more than the electricity consumed in the United Kingdom.
To gain a finer-grain view of this power consumption, we partitioned it into our classification system as follows (see Figure 2):
Figure 2. “Who Consumes This Energy?” from Defining the Digital Infrastructure Industry. (Source: iMasons Digital Infrastructure Industry Baseline Paper.)
Although forecasts are imperfect, input from iMasons members across data center equipment providers, colocation providers, construction firms, and edge capacity reports indicate that the digital infrastructure industry will add 20,000 MW of new data center capacity by the end of 2024, concentrated in India, Africa, and Latin America. As it is, the industry in 2021 had 36,860 MW of unused capacity, according to the conservative end of iMasons’ estimates. A concern with the projected growth of new data center capacity is a perpetuation of the low utilization of built capacity around the world, which is unsustainable economically and ecologically.
Clarity on the size of the digital infrastructure industry helped settle a long-running debate about how much of the global energy supply goes to data center operations. Most of the estimates are based on extrapolations of partial data and ranged from 1 to 10%, with most coming in below 2%. The lower-end estimates highlight increased power use effectiveness (PUE), a digital infrastructure industry measurement of how efficiently data centers use energy. It is determined by dividing the total amount of power entering a data center by the power used to run the IT equipment in it. A rating of 1 is perfect efficiency.
Industrywide, PUE has dropped from 2.5 in 2007 to 1.55 in 2022, according to data from the Uptime Institute. Increased PUE has allowed the digital infrastructure industry to grow in capacity without a commensurate increase in power consumption. As PUE gains across the industry slow and capacity continues to increase to accommodate more powerful artificial intelligence workloads and increased spread of blockchain technologies, we need to focus our efforts on reducing embodied carbon in materials and equipment and the carbon intensity of the power consumed to operate our data centers.
Many iMasons member companies have already established goals to achieve carbon neutrality in this decade as a step toward net zero by the middle of this century. To achieve these goals, they track their carbon footprint, purchase renewable energy to power digital infrastructure, and invest in R&D efforts to reduce embodied carbon in materials and equipment. These individual efforts provide leadership throughout the digital infrastructure industry and yet are insufficient to move the needle on climate change. We can and must do more.
On 22 February 2022, the iMasons Advisory Council convened to discuss how the digital infrastructure industry can reduce its climate impact. The meeting felt historic: a convening of representatives from some of the largest companies in the world, all committed to doing something together. The impacts of climate change were all around us: extreme weather, wildfires, rising seas, and other global catastrophes. We were compelled to act, to lead by example. If we come together as an industry, we said, we can compound the work of individual companies striving to reduce their climate impact and shorten the timeline to carbon neutrality and net zero. Six hours later, the seeds were sown for the iMasons Climate Accord (see Figure 3).
Figure 3. (Left) Dean Nelson and Christian Belady at the official launch of the iMasons Climate Accord at the Datacloud Global Congress Monaco on 25 April 2022.
To begin, the accord unites members of the digital infrastructure industry on measuring carbon in power, materials, and equipment. If we can measure it, we can improve it. The accord also encourages members to maximize existing data center capacity, use more sustainable materials in new builds, use power more efficiently, and develop environmentally friendly technologies. All signatories are held accountable for transparency and traceability on embodied and operating carbon to declare their carbon footprint and document their carbon-reduction efforts. To achieve these goals, the accord calls for an industrywide, open standard that every data center can use to report and track carbon.
The effort to define digital infrastructure allowed us to calculate that the digital infrastructure industry’s 7 million data centers consumed 594 TWh of energy, or 2.4% of the world’s total, in 2021. How much energy is consumed, however, fails to reflect the carbon intensity of that consumption. Carbon intensity is a measure of the amount of carbon emitted per unit of electricity produced. A data center that draws power exclusively from sources of renewable energy, such as a hydroelectric dam or wind and solar farms, has a lower carbon intensity than a data center that draws power from a grid that carries electrons generated at coal and natural gas-fired power plants.
The ability to identify each of the 7 million data center locations, i.e., unique street addresses, worldwide, means that we can model the carbon intensity of each individual data center, establishing a baseline for each location’s embodied and source energy carbon footprint. That’s because each data center location (address) can identify the makeup of the facility’s material and equipment and how much power it consumes from power sources. Doing so will provide each data center with a baseline to measure and track carbon-reduction efforts.
Today, members of the digital infrastructure industry take two primary approaches to reduce the carbon intensity of their power consumption: they procure clean energy through power purchase agreements with generators of clean energy such as solar and wind farm projects, or they purchase certificates or credits for the generation of a specific amount of clean energy.
Power purchase agreements are typically for 5–20 years and ensure revenue for the generator, which enables project financing and gives the purchaser a guaranteed price and availability. The carbon-free electrons generated through these agreements are typically added to the electric power grid rather than to a dedicated feed from the project to the data center. The agreement ensures that the project supplies the same amount of renewable energy to the grid that the customer agrees to consume from the project. Hyperscale data center operators tend to enter into power purchase agreements because they want their purchasing power to add more renewable energy to the grid than what would have been produced had they not entered into the agreement. This is known as additionality.
Renewable energy certificates, credits, or guarantees of origin indicate that a unit, typically 1 MWh of electricity generated from an eligible renewable source, was put onto the grid. Each certificate is a tradeable asset until an owner makes a renewable energy claim based on it. Once a claim is made, the certificate is retired. In the digital infrastructure industry, these certificates are typically used by data centers that lack the scale necessary to justify the additionality of a power purchase agreement.
The concrete industry accounts for approximately 8% of the world’s total carbon dioxide emissions. The bulk is released during the manufacturing of cement. To make cement, limestone and clay are heated in kilns that split the materials into carbon dioxide and marble-sized balls of calcium oxide called clinker, which is cooled and mixed with other materials that become the binder for concrete mixes. Steel production accounts for roughly 7% of global carbon emissions, primarily due to the process of transforming iron ore into steel in blast furnaces. Digital infrastructure is built using concrete and steel.
To reduce embodied carbon in concrete and steel, member companies of the iMasons Climate Accord are working with and investing in suppliers of low- and no-carbon building materials in the concrete and steel industries. Similar to the power purchase agreement model for renewable energy, these investments spur R&D and signal market support for materials with reduced carbon. As these materials scale to production quantities, these early investors are guaranteed access to them to use in their new digital infrastructure builds.
To measure the digital infrastructure industry’s carbon footprint today fully and accurately, we need to account for the carbon embodied in the concrete, steel, and other materials used to build digital infrastructure. This includes concrete floors and steel walls; the materials in mechanical, electrical, and plumbing equipment such as uninterruptible power supply systems, generators, and cooling infrastructure; and the IT equipment housed in data centers, such as servers and network switches. As equipment is swapped out or upgraded, the carbon accounting must be updated accordingly.
The digital infrastructure industry has yet to reach consensus on a transparent, open standard to track and report embodied carbon. Ideas include labels like those on cereal boxes that list grams of fat and sugar for each data center location, or a QR code at each data center that points to a database with a detailed accounting of that location’s embodied carbon.
Embodied carbon accounting for facilities and the equipment in those facilities plus the carbon associated with the power consumed to deliver electronic services would enable real-time tracking of the carbon footprint for each data center location. Going a step further, our members are now working to define a standard unit of measure to account for the carbon associated with each packet of data that goes in or out of every data center in the world.
The builders of the digital age represent some of the largest, most profitable, and visible companies in the world. Our purchasing decisions influence global markets and behavior. Today, the iMasons Climate Accord is spurring collaboration across the digital infrastructure industry as a necessary first step to achieve net zero. Working together, we can compound the sustainability impact of each member company and make the sum greater than the parts.
Infrastructure Masons. [Online] . Available: https://imasons.org/
The iMasons Climate Accord. [Online] . Available: https://climateaccord.org/
Dean Nelson (dean@imasons.org) is the founder and chair of Infrastructure Masons, Beaverton, OR 97003 USA.
Digital Object Identifier 10.1109/MELE.2023.3291191
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