Kicking the carbon habit

We all know that the demand for data centres is growing rapidly, but the sheer scale of the industry is worth taking a moment to recognise. Respected industry analysts IDC estimate that the global data requirement will have reached 163 zettabytes by 2025. That estimate is based on the expectation that the global data centre industry will have enjoyed a compound annual growth rate (CAGR) of around 17% for the period 2019 to 2023.

Data centres are energy intensive. According to various estimates, they account for 2% of the world’s energy consumption – roughly equivalent to the aviation industry. While large strides forwards have been made, designing, developing and operating sustainable data centres remains one of the biggest challenges for all parts of the industry.

Besides the obvious imperative on everybody to help save the planet, the need to make data centres greener is also driven by both customers and regulatory authorities. With the former often being large multinationals with well-advanced corporate social responsibility programmes and the latter having sustainability extremely high on their agenda (a net zero carbon economy by 2050 is often the ultimate goal), the pressure to continually improve and develop is considerable.

It is important to recognise that many steps have already been taken to reduce carbon at an operational level. We are seeing initiatives such as use of renewable power onsite, rainwater reclamation, smart control of lighting and temperature, improved use of by-products, efficient recycling and effective waste management.

However, the undoubted impact of these operational initiatives must be enhanced by driving efficiencies and better approaches during the construction phase. Among the trends that we are already seeing or expect to see over the coming years are:

1. Use of innovative materials

Use of low carbon or more sustainable materials does require significant planning and suppliers to be researched and engaged with, but there are certainly many new avenues to explore.

2. Adoption of modern building techniques

Prefabrication has a reputation for having a lower environmental impact than traditional construction. More construction off-site means less waste, as the controlled conditions and repetitive nature of the works enable output to be more precise with fewer mistakes. This approach also claims to offer more efficient recycling and waste disposal, in addition to generating fewer greenhouse gas emissions. Also, modular components reduce the time and intensity of on-site construction, which reduces the amount of waste materials, emissions, noise pollution, construction traffic and road closures

3. Hydrogen

While still very much a work-in-progress idea, the fact that hydrogen offers the highest energy per mass of any fuel (by weight) and is the most plentiful element, suggests plenty of untapped potential. Data centres are already exploring this option, but there is certainly scope for further development.

4. Data passports

Low-carbon materials are increasing in popularity and the use of “data passports” is just one method of encouraging and measuring their use.

Embodied carbon

Efforts to cut carbon have focused on the operational carbon impact of data centres, the logic being that CO2 emitted while a data centre is in use is at least double that of its embodied carbon – i.e. emissions caused by the production and transport of materials and construction. While operational carbon is relatively easy to measure, its embodied counterpart has so many different facets that measuring and monitoring are far from straightforward. Just as a guideline, Linesight estimates that, simply in the construction phase, concrete accounts for around 40% of the carbon produced, with fuel being the next biggest contributor at 25%. Reinforced and structural steel then account for around 10% each.

With clear gains to be made from reducing embodied carbon, it will become a more important area of focus as data centres strive to satisfy both regulatory and organisational carbon targets. “What gets measured, gets managed” is especially true when looking at sustainability, so measuring embodied carbon will be the foundation of all efforts to reduce embodied carbon. However, embodied carbon is challenging to measure and it is an area that we are actively working with our clients to develop strategies to address.

Specifying and gathering all the relevant data is therefore critical and, in this particular sphere, still evolving. Engaging with all the relevant parties across the supply chain will be critical in ensuring that the required large strides are made in this area in the near future. Meanwhile, the industry is also pushing itself to do better. In 2019, the UK became the first major economy to pass a net zero emissions law, requiring the UK to bring all greenhouse gas emissions to net zero by 2050. However, the data centre industry has made its own pledge, led by companies such as Google and Equinix, to achieve climate neutrality by 2030. This is the Climate Neutral Data Centre Pact (CNDCP), which requires the following:

Increase and measure energy efficiency

There’s no shortage of sustainable activity going in the data centre space. Hyperscalers such as Amazon, Microsoft, and Google have made carbon-neutral commitments and have made significant investments in sourcing renewable energy for their facilities. And in 2021 alone, the likes of ChinData, MTN, and IBM have made similar pledges. However, much of the conversation is still around operational sustainability and ensuring the facilities use as little power as possible, use green energy where they can, and have minimal or even carbon negative impacts on the local area through district heating initiatives and natural cooling. But is enough thought being given to the environmental impact of the construction phase around data centres and the material impact of the construction materials they use? Data centres use huge amounts of concrete and steel which are major sources of CO2. And as the sustainability gains from operational efficiencies dry up, firms will have to look to embodied carbon in the construction phase if they are serious about being climate neutral.

Clean energy

Carbon neutral data centres should be powered by 100% renewable energy. The Pact states that data centre electricity demand will be matched by 75% renewable energy or hourly carbon-free energy by 2025 and by 100% by 2030.

Water efficiency

Data centres rely on vast amounts of water for computer cooling and the Pact calls for this to be minimised. The water metric target - water usage effectiveness (WUE) or other metric - may vary depending on the design specification.

A circular economy

Data centre operators must apply circular economy practices to repair and recycle servers.

Circular energy system

The Pact highlights the energy conservation opportunity presented for the reuse of data centre heat. Data centre operators can “explore possibilities to interconnect with district heating systems and other users of heat” in a way that is practical, environmentally sound and cost effective.

While tracking and quantifying the carbon footprint of a data centre’s construction is hard to do, data is undoubtedly fundamental in quantifying, understanding and reducing the environmental impact within the construction space. What gets measured gets managed. There are things clients can do now that will help:

- Avoid landfill where possible

- Use salvaged or reclaimed materials

- Reduce cement usage in concrete mixes through fillers

- Use synthetic gypsum for plaster and drywall

- Buy green insulation such as cellulose or denim insulation/natural cotton fibre insulation

- Opt for rubberized asphalt made from recycled tires

- Utilize recycled steel where possible

- Source locally for as many materials as possible

- Use modular designs and build off-site

The transition to a net zero carbon industry requires a shift in the way data infrastructure is planned, designed and built. A Net Zero Carbon approach sets out a project pathway to embed best practice sustainable design principles into each project stage. Linesight’s holistic, data-informed service delivery model tackles the building design, materials, engineering solutions, construction and operation, to provide a truly whole-life net zero project. We can also help clients to embed sustainable principles and technology to achieve energy and resource efficiencies in line with commercial objectives. Working in partnership, we provide support right from project inception through early supply chain engagement to cost effective and pragmatic advice for design solutions and operational objectives.