Decarbonising data centres – rethinking design of digital infrastructure

With the rapid growth in AI and cloud-computing the data centre sector is in expansion mode, with data from CBRE showing that in the first quarter of 2024, there was 22% year-on-year expansion of the available data centre capacity in Asia Pacific, with Sydney, Hong Kong, Singapore and Tokyo leading the charge for capacity.

However, if conventional thinking for design, delivery and operations dominates, the energy demand and the emissions footprint of facilities may become unpalatable for both investors and regulators.

Already the International Energy Agency states the global data centre sector’s energy consumption could reach 1,000 terawatt hours (one million megawatt hours) by 2026 – roughly equivalent to the entire electrical demand of Japan. This poses a challenge for energy resources as the wider urban environment, transport, infrastructure, and manufacturing all concurrently speed up the electrification transition to reduce emissions from gas, oil, and coal consumption as power sources.

An additional pressure is coming from outside the data centre sector. Regulators and investors are both alert to the risks of rampant energy demand and the corresponding carbon footprint. In Australia, for example, in most states the grid is still highly reliant on coal and gas fired plants for a significant proportion of the main electrical supply.

The Australian Federal Government has already specified a requirement for NABERS ratings for all new data centre projects commissioned via its provider panel, and the revision of the Commercial Buildings Disclosure legislation is proposing all data centres within just a few years will be required by law to obtain NABERS ratings.

General design and delivery considerations

For many building types, to reduce energy demand on-site solar PV is a good solution, however solar PV on data centres cannot generally meet the scale of energy demand inside, and brokering agreements to develop off-site renewable sources competes with the utility-scale renewables being developed for meeting basic community and industry electrical demand.

The reason data centres require so much energy is not simply to power the digital operations of racks and chips and processors. These all require stable environmental conditions in terms of temperature and humidity to operate, while also generating significant amounts of heat. This means that mechanical cooling and ventilation are mission-critical building services for data halls.

The design and equipment for data centre building services are therefore evolving rapidly to meet the need for fast, reliable and secure digital real estate while also minimising impact on climate change and on local energy grid stability.

Data Centre providers, technology suppliers and vendors are now being challenged to innovate at a pace not previously seen, to minimise the environmental footprint of facilities and also to establish a point of differentiation through engineering and technology, while not compromising on speed to market and resilience.

There are several technologies and strategies being utilised to achieve this.

Advanced solutions for digital real estate

The use of digital parametric design can help to optimise building services schematics and reduce embodied carbon/materials such as copper cabling, ductwork and pipework. The use of BIM and a robust quality assurance process during construction to ensure design goals and specifications are achieved in the final construction are also critical.

A leaky building envelope will compromise not only the thermal performance, it imposes additional strain on ventilation systems to maintain the positive pressure and pressurisation control including differential pressures in data halls that act to prevent dust and other contaminants entering the space as well as design airflows.

Heat-sharing strategies can deliver a major win in terms of social responsibility and potential social carbon offsets. What is often termed ‘waste heat’ from data halls or the operations of the cooling system essentially equates to wasted energy, as that heat energy can feasibly be utilised for other purposes.

Looking beyond the site boundary for opportunities to share waste heat can deliver emissions reductions at the community scale. This was part of the approach used for the world’s first net zero data centre at Odense in Denmark. The heat from the data centre feeds into a community district heating grid – reducing reliance on coal for warmth in homes and businesses.

Free air cooling and hybrid cooling and ventilation strategies underpinned by smart building technology and control systems can also reduce energy demand. The key for data halls is maintaining air free of dust, particulates and other contaminants, as the equipment is very sensitive, which is why delivery of these projects is demanding and requires scrupulous quality of materials and trades skills.

Next-gen building services

Liquid cooling as a new technology is looking to become mainstream in all data centre designs. These breakthrough products focus on cooling high density heat-generating IT racks, where the limits of traditional air-cooled solutions are reached.

When this is coupled with appropriate water source heat rejection, these technologies can lead to significant savings on energy demand. Overall, it is important to optimise water usage and efficiency in data centre services, particularly in regions with limited supplies such as many parts of Australia.

As part of the electrical system design, the controls can incorporate prompted load shedding to align with electricity grid demands. Careful design of implementation is required so this does not compromise resilience and to ensure solutions respond to the dynamic conditions of overall data centre load.

Monitoring and control systems are critical at all levels of the electrical topology to achieve a well thought out solution. An opportunity exists in all data centres to harness monitored data.

This leads to the next point: as the industry seeks to innovate to capture more and more of the growing market, what steps can be taken to future-proof an operational facility? As major customer lease deals end, how do current facilities compete with the newer generation data centres to remain relevant?

Trimming on-site emissions

Carbon reduction opportunities include reviewing the number of generators at the site, where the AI operations or functionality of the data centre allows. Design of availability zones to enhance cloud-based resilience is something which would need to be driven and led by Data Centre owners, based on location and connection between data centres.

Diesel does not need to be the default for generators either. Biofuel solutions are beginning to become available that can switch out the fossil fuel for renewable alternatives. Robust and resilience electrical design can also incorporate battery energy storage (BESS). There are some project specific considerations such as the location of the BESS and the required area of the data centre footprint, however they can be used to reduce reliance on backup diesel generators depending on the BESS specifications.

This article was originally published at Sourceable.