07 December 2022

Data centres play an essential role in our increasingly digital world; however, they also consume up to 3% of global power production. This is only going to rise in line with exponential data generation. Amy Saunders explores how UK data centres can aim for climate neutrality

Data centres, whether real or virtual, provide an essential service as centralised locations for processing organisations’ IT operations and equipment to store, process and disseminate data.

The post-pandemic market

In the UK, data centre market demand has boomed since the onset of the COVID-19 pandemic. Some capex was delayed by the pandemic, with contracts remaining incomplete until social distancing rules ended, however, that time is now behind us.

Research and Markets reports that there were more than 200 third-party data centres in the UK with almost 1 million square metres of raised floor space and more than 1,000MW of data centre customer power (DCCP) at the end of 2021. Data centre space is expanding by existing data centre providers at more than 50,000 square metres annually, mainly within the London and Inner M25 and Slough areas. An additional 20,000 square metres of data centre space is being added to the UK market annually by regional data centre providers. Investment in data centre capacity in lower cost regions will be a key trend going forward. UK data centre revenue growth of 36% is expected over 2021-2025, while data centre space and power are forecast to grow by 26% and 29% over the same period.

The London data centre market represents around 80% of the UK total. CBRE reports that in the first quarter of 2022, there was 17MW of capacity take-up and 46MW of new supply. Demand from hyperscalers remained strong despite considerable market constraints, and is expected to accelerate in the second half of 2022, particularly in London, with wholesale lettings to single tenants, usually hyperscalers, dominating the market.

“The UK and Ireland data centre sector continues to experience year-on-year growth, with London being home to the world’s second largest hyperscaler market,” said Billy Durie, global sector head for data centres at Aggreko. “However, with the energy consumption of these facilities now rising in line with this market expansion, ensuring that this growth takes place in a sustainable manner is more important than ever.”

Mordor Intelligence reports that the UK is home to more than 5.5 million businesses that rely on cloud services, which, when combined with non-business IT cloud needs, could potentially lead to 7,446kWh power use by data centres annually by 2025, more than the total renewable generation standard. To maintain renewable generation standards, the UK government issued a regulation which requires all companies with 250+ employees to report their power usage under the Energy Savings Opportunity Scheme (ESOS). This is expected to drive the demand for energy-efficient data centres.

Climate neutrality

Data centres are estimated to consume anywhere from 1-3% of a nation’s total power consumption.

“Fortunately, the gravity of this situation is being recognised, with data centre operators and trade associations agreeing to make data centres climate neutral by 2030 as part of the Climate Neutral Data Centre Pact,” said Durie. “It would be fair to say that sustainability is now a top priority for those operating in this region.”
Indeed, many have committed to becoming climate neutral by 2030, and as of July 2022, 74 data centre operators and 23 associations have signed up to the Climate Neutral Data Centre Pact, which requires:

Increase and measure energy efficiency - European data centres and server rooms shall meet a high standard for energy efficiency through aggressive power use effectiveness (PUE) targets. By 1 January 2025 new data centres operating at full capacity in cool climates will meet an annual PUE target of 1.3, or 1.4 for new data centres operating at full capacity in warm climates. Existing data centres will achieve these same targets by 1 January 2030.

Clean energy - Carbon neutral data centres should be powered by 75% renewable energy by 31 December 2025 and 100% by 31 December 2030.

Water efficiency - Water use is to be reduced to a minimum by the application of a location and source sensitive water usage effectiveness target (WUE). By 1 January 2025, new data centres in cool climates must be a maximum WUE of 0.4L/kWh in areas with water stress. By 31 December 2040, existing data centres that replace a cooling system should meet the same target.

Circular economy - Operators must apply circular economy practises to repair and recycle servers, as well as reusing waste heat where possible.

Circular energy - The reuse of data centre heat presents an opportunity for energy conservation that can fit specific circumstances. Data centre operators will explore possibilities to interconnect with district heating systems and other users of heat to determine if opportunities to feed captured heat from new data centres into nearby systems are practical, environmentally sound and cost effective.

Legacy data centres represent one of the biggest challenges; those built 10 or more years ago consume huge amounts of energy and will require heavy investment in the years to come for decarbonisation. For newer and upcoming data centres, however, there are many features that can be incorporated from the planning stages to produce a more environmentally friendly facility. Immersion cooling, the application of artificial intelligence for workload management, and sourcing renewable materials for construction are just the tip of the iceberg. As well as proving positive for the environment, such measures lower opex for the lifetime of the data centre.

Sustainability: power is key

Sustainability has been important for all those in the UK’s value chain for some time now, according to David Watkins, solutions director for VIRTUS: “For over a decade we have recognised the need to produce more efficient data centres, actively lowering PUE and WUE with innovative designs. These ongoing efficiency efforts have ensured that the industry has already made great strides to mitigate their impact on the environment.”

Simon Brady, head of data optimisation at Vertiv, agrees: “Sustainability is a priority for all data centre providers in the UK. With the growth of internet 2.0, IoT, AI and everything as a service, the industry’s energy usage is only going to increase. This means we MUST put sustainability at the core of our business model.”

However, unique challenges arise from creating greener data centres. “While data centres don’t generate waste or products like other industries, this high energy and water-use sector faces unprecedented demand for sustainability measures and efficient facilities. The most forward-looking providers are committed to delivering a ‘cradle to grave’ green strategy, where environmental ambitions are built into every step of data centre design, construction and maintenance,” said Watkins.
Durie agrees, highlighting two key aspects for consideration: “operational emissions, and embodied emissions. The former often dominates this conversation, and concerns reducing the carbon footprint of day-to-day operation through limiting water and energy usage or making use of renewable sources. However, it is also important to address the issue of embodied emissions – all carbon expended during the construction of a new facility. Given that new data centres continue to be constructed all the time, only through assuaging both these concerns can the sector become more sustainable.”

There are a range of technologies and solutions in play that can help reduce emissions from data centres. “Better thermal management of legacy sites by removing high-energy consumption mechanical cooling systems could make a difference. The main obstacle is fear of change and how that will impact availability and uptime,” said Brady.

“Power used for cooling accounts for much of the emissions from data centres,” said Watkins. “We have deployed well-established technology developments to tackle power usage such as liquid, evaporative, fresh air and adiabatic cooling. Direct chip liquid cooling can offer some of the lowest PUE possible as the temperature at which they operate means that no mechanical or adiabatic cooling would be required. Renewable carbon-zero energy is also an important part of the strategy to reduce carbon emissions.”

Durie reiterated that power, often supplied by diesel gensets, is a key source of carbon emissions during data centre construction. “The main aspect to consider here is right sizing – opting for solutions that do not exceed the power demands of the site,” he explained. “This can be difficult due to the varying load demands of an active construction site, but can be achieved through a load on demand system, where several smaller generators are favoured over a singular large unit, scaling up or down as required. This leads to a significant reduction in fuel consumption, and in turn carbon emissions. By taking this one step further and switching to a hybrid and load on demand system of two 60kVA Stage V generators, a typical site with power requirements of 200kVA can achieve a 50% reduction in CO2 emissions and fuel consumption.”

Going green in the UK

When it comes to creating climate neutral data centres, there are a wealth of options.

The first step is the move away from fossil fuels. “Data centres are particularly well placed to benefit from renewable energy sources due to their stable power consumption,” explained Watkins. “VIRTUS was the first UK provider to commit to using 100% carbon-zero energy – powering its sites solely with truly renewable energy from wind, solar and tidal sources since 2012. By doing this, VIRTUS saves around 45,000,000 tonnes of CO2 every year, enough to fill Wembley stadium five times over.”

Hydrotreated vegetable oil is proving a popular alternative fuel within the UK: “instead of making use of diesel in gensets, data centres can substitute this fuel for hydrotreated vegetable oil, a greener alternative that can facilitate up to a 90% reduction in carbon dioxide (CO2) emissions and a 15-25% reduction in nitrous oxides (NOx) and particulate matter (PM),” said Durie.

Watkins agrees that “the use of hydrotreated vegetable oil instead of diesel in generators has the potential to reduce carbon emissions by up to 90% - as well as eliminating sulphur dioxide emissions and reducing harmful nitrogen oxides.”

Other technological developments in areas such as fuel cells are continuing at a pace “and whilst they’re not viable right now, if they can perform at scale, they might present a compelling option for future green data centre power,” added Watkins.

The application of other renewable energies, however, is more complex: “some data centres are investing in onsite generation of lower carbon sources of energy, but today the power density is not available, partly because wind and solar require a lot of space which isn’t conducive to the very high density of power a data centre needs,” said Brady. “UPS technologies that offer dynamic grid support through battery backup are possibly the way forward. To green data centre power consumption, the energy suppliers need to add more low carbon power to the grid. The higher the percentage of lower carbon sources, the greener everyone’s power consumption will be.”

A sustainable future

To continue to strive for the most sustainable data centres, operators must consider a green design from the outset.

“We need to build sustainability into design, right through to end of life and existing owners/operators should invest more in upgrading legacy sites to make better use of the energy they consume. Given the current increases in energy costs the ROI for such projects can now be measured in months rather than years,” said Brady. “ESG must continue to be a focus during everyday operations and when technology refreshes happen.”

“As the UK and Ireland data centre market continues to grow, decarbonising both day-to-day operations and the construction of new facilities will be key to achieving truly green data centres,” added Durie. “Through incorporating technologies such as Stage V generators and HVO and taking a more granular approach to all aspects of carbon emissions, the sector will be able to achieve its goal of carbon neutrality by 2030.”

With data centres very much a staple of modern-day life, the push towards sustainability is a must.

“One of the most efficient ways to deliver a unit of computing (energy per compute unit) is to put it in a large, modern, advanced data centre on a cloud platform. These data centres are also far more energy efficient in comparison to previous models of computing,” said Watkins.

Moreover, at the consumer end of the scale, common data service uses like online shopping and remote working have delivered sustainability benefits throughout the chain, reducing the CO2 emissions associated with travel. Thus, while the data centre segment may have a way to go yet before achieving climate neutrality, the impact of data centre services is already delivering widespread green benefits throughout the UK, and indeed, the world.