Data centres, energy savings heating up

Mitsubishi Electric

In partnership with AACS Ltd

Data centres are vital for almost every sector in the UK economy, but they are energy-intensive buildings.
TechUK, the membership organisation for technology businesses in the UK, estimates that data centres consume 2.89TWh of power per year.  

However, the sector also recognises that it has a role to play in achieving the UK’s carbon reduction ambitions.

The TechUK report UK Data Centre Sector Energy Routemap (November 2019) states: “The sector is a large electricity consumer with stable, predictable demand and significant embedded capacity. For these and other reasons it is well-placed to help support the transition away from an economy dependent on combustion and towards one based on renewables.”

​Agreed targets
The data centre sector has a Climate Change Agreement (CCA). This is a negotiated agreement with government offered to energy-intensive industries. In return for a reduction in or exclusion from paying some carbon-related taxes, participants commit to energy efficiency targets – specific to that industry.
The CCA for the data centre sector ran from 2014 to 2020. Government announced in early 2020 that it would extend CCAs to 2025.

The potential annual savings in carbon-related taxes can run to many thousands of pounds for data centres.

Higher energy costs
UK data centres also face higher energy costs than many other parts of the world.

In a global market where the geographical location of clients may not be a factor in data centre location, this makes energy efficiency a competitive issue.

There are, therefore, genuine benefits to continuing to make energy reductions wherever possible for data centre owners and operators.

UK data centres have shown firm commitments to energy efficiency and sustainability. Almost all of the CCA participants are compliant with ISO 140001 and half have signed up to the EU Code of Conduct for data centres.

However, more can be done, particularly in the building services arena.

Reusing heat
One of the potential savings highlighted by TechUK is the reuse of heat.

Data centres produce large amounts of heat as a by-product which is often simply expelled from the building. However, technology is readily available that can make heat reuse a highly cost-effective option.
Heat recovery captures heat rejected from a cooling system and applies this to other areas of building services such as space or water heating.

It is possible to save significant amounts of energy while reducing long-term operational costs.
Clearly, in a building which ejects large amounts of heat, the ability to use that energy elsewhere has enormous potential.

A range of options
There are several approaches for heat recovery, and Mitsubishi Electric has a range of technologies that provide heat recovery to both new-build and existing projects.

For example, simultaneous heating and cooling chillers are particularly useful in data centres where there are coincidental heating and cooling loads. The heat extracted from areas that require cooling can provide heating to occupied spaces in the data centre, such as offices. It can also boost the temperature of hot water to reduce the load on boilers.

For those looking to move away from gas boilers altogether (to make use of clean electricity, for example) there are chillers with simultaneous heating.

One of the primary benefits of this approach for new-build projects is that no gas boiler is required since the system provides cooling and space / hot water heating – removing the need for a gas connection.

The 4-Pipe Integra Chiller is an excellent example of this approach

It is also possible to use a dedicated heat recovery heat pump. The water-source heat pump uses the condenser water or return chiller water as its energy source. It is an excellent approach for large water-cooled chiller applications that improves the performance of large-capacity chillers and dedicated plant – enhancing the ROI of capital expenditure and improving long-term performance.

Data centres are now critical infrastructure for the UK. As significant energy users, they also have the potential to lead the way on the use of smart approaches to cooling and heating.