E D I T O R ' S Q U E S T I O N

• Increasing the total provision of plant directly results in more embodied carbon associated with MEP equipment

• The increased plant provision is also likely to have a structural impact , increasing the quantities of structural steel and concrete and consequentially , further increasing the embodied carbon

• Oversizing of equipment can impact real-world efficiencies

• Reliance on fossil fuel-powered generators as a backup power source

• Increased plant provision

Resilience is not just limited to redundancy , however , and there are further design choices which can bolster the resilience of the data centre such as oversizing of equipment to allow for climate change scenarios .

Many of the above factors can either be in support of or in conflict with the sustainability of the data centre .

Location

Intuitively a data centre located in a cold climate will have a lower cooling demand as there is greater opportunity for free cooling . Lower annual demand will typically coincide with a lower peak demand . A lower peak demand will mean fewer plant or smaller plant which in turn will reduce the redundancy requirement and reduce the required capacity of UPS and generators . All of which will reduce the embodied carbon .

Backup power and UPS

Load-switching UPS technology can be utilised which utilises a modular system . In doing so , UPS modules can be turned off when the demand is low to ensure that individual units operate at a higher efficiency . Diesel generators can be replaced with Hydrogenated Vegetable Oil ( HVO ), which produces around 10 % of the emissions when compared to diesel .

Waste heat utilisation

Waste has an obvious environmental benefit in that the energy produced by the servers and subsequently rejected from the data centre is no longer wasted . The heat reject also serves to reduce the demand as the return temperatures to the chillers are effectively lowered . In the process .

Data centres must make it easy for network operators to utilise the waste heat . This includes ensuring there is a single point of connection as close as possible to the existing or planned networks . Ultimately for this to be economically feasible , large grids with diverse demand profiles which favour low-grade heat are required . This would require significant investment from governments in regions where this does not exist . However , by siting data centres in areas with existing networks such as the Fjenvarme Fyn in Denmark , the waste heat can be exported .

Water source cooling

The location of a data hall close to a body of water can increase the resilience and sustainability of the building . Innovations such as floating data centres or underwater data centres show that cooling demand can be reduced because water temperatures are typically lower than the surrounding air . Resilience can be increased as water is not subject to the swings in temperatures which occur in the ambient air .

Microsoft ’ s underwater data centre pilot in the Orkney Islands showed a server failure rate around 8x lower than on land . Additionally , Subsea Cloud has claimed that such data centres will use 40 % less carbon and have zero water consumption .

Cooling innovation

Two major buzz terms in the industry are liquid cooling and immersion cooling . Liquid cooling removes the need for CRACs / CRAHs removing a potential point of failure . It also enables better cooling of the chips reducing their likelihood of failure . There is also faster recovery in the event of failure and therefore reduced downtime . By eliminating the need for air distribution within the data halls a significant reduction in energy consumption can also be achieved .

Immersion cooling has the potential to significantly increase resilience . The liquid acts as a barrier to contaminants such as dust which can cause failure . In the event of a power outage , the liquid can continue to cool the servers for a period due to the thermal mass of the liquid . while eliminating the need for fans to reduce energy consumption .

Due to the liquid ’ s heat capacity , the servers are somewhat protected from ambient temperature swings . This will reduce the peak demand reducing the size and amount of equipment . �

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