In 2017, a group of researchers estimated global data centres could use 25% of the world’s electricity by 20251. This is more electricity than any country in the world, including the US. This prediction is not materialising thus far, and raises the question of how much energy and electricity data centres actually consume?
The world’s data centres consume around 200 Terawatt-hours (TWh) of energy annually, almost all of it electricity2, accounting for about 1% of the world’s electricity consumption. While this is much lower than the prediction, it still makes data centres a considerable consumer of energy.
However, the data centre industry has made significant progress to improve its energy efficiency. This has resulted in a plateau in data centre energy consumption in recent years. What is even more exciting is the industry’s ability to achieve such a plateau while successfully meeting its customers increased need for services. Below are three data centre energy trends:
- Increasing environmental consciousness is driving a focus on decarbonisation
From airlines to data centres, lowering carbon emissions and decarbonisation are increasingly gaining traction across most industries. In the process of consuming 200 TWh of electricity, data centres create a significant carbon footprint. This is because they commonly rely on the world’s current power generation mix, which is still heavily fossil fuel based.
Two of the most popular decarbonisation paths within the data centre industry are the direct use of renewable energy sources and the use of renewable energy credits (RECs). These two approaches are expected to co-exist in the data centre industry’s path towards decarbonisation.
Direct use of renewable energy sources: This is where a data centre is fully or partially powered by renewable energy, for example geothermal, hydro, solar and wind. While this is the more environmentally-beneficial approach, it is also more challenging due to the intermittent nature of renewables. Data centre operators rely either on existing electricity markets or, in some cases, energy storage options to manage this challenge.
Use of renewable energy credits (RECs): In this scenario, data centre operators purchase renewable energy and associated RECs. In cases where the renewable energy is produced in a location far away from the data centre, the operator sells the renewable energy back to the grid and uses RECs to offset its carbon footprint. This is a common approach across the data centre industry, and is partially what makes Google the largest corporate buyer of renewable energy in the world3.
This approach is beneficial because it gives the renewable energy provider the customer commitment to invest in new projects, even if the renewable energy is not necessarily used by the data centre. In other words, this approach delivers an increasing quantity of renewable energy to the grid for all to use. Meanwhile, critics highlight that this approach doesn’t necessarily reduce a data centre’s carbon contribution.
- An increase in on-site energy generation
Data centres commonly rely on the grid as the primary source of electricity. While relying on the grid is convenient, the continued expansion of data centres could place extra stress on existing grid infrastructure, resulting in grid instability. In some regions, data centre growth and energy demands could outpace grid infrastructure capability and investment. To address these challenges, some data centre operators may deploy on-site power generation.
Photovoltaic (PV) arrays, natural gas generator sets and fuel cells are common sources of on-site generated power. These sources are also known as distributed energy resources (DER). They may operate connected to the utility or isolated from the utility (known as island operation) as a microgrid. Stationary energy storage may also be incorporated into a microgrid, enhancing the ability to operate in isolation from the utility.
On-site power generation allows a data centre operator to use power from cleaner sources when available, while supplementing energy from other sources when the cleanest source is not sufficient. This feature of on-site generation supports advancement towards sustainability goals, while maintaining reliable power service to the data centre.
- Achieving higher levels of energy efficiency
Data centres offer vast opportunities for energy efficiency, and the industry has taken full advantage in recent years. Let’s cover two aspects of energy efficiency in a data centre.
IT infrastructure: Historically, data centres improve the energy efficiency of IT infrastructure through higher utilisation of individual IT equipment and server virtualisation. Going forward, converged infrastructure (CI) and hyper-converged infrastructure (HCI) are expected to lead energy-efficiency gains in data centres.
Simply put, CI’s building blocks are made up of storage and compute functionalities physically combined in a turnkey product. Meanwhile, HCI relies on a software to combine compute, storage and networking functionalities. Both technologies, in different ways, deliver a more scalable architecture to assist with energy efficiency. Within a data centre, to deliver the same computing output, you can afford to have fewer servers, storage and network equipment if you are using one of these technologies.
Non-IT infrastructure: Power usage effectiveness (PUE), the ratio of total energy used by the data centre to the energy used by computing equipment, is a common indicator of a data centre’s energy efficiency. The industry average PUE improved from 2.5 in 2007 to 1.67 in 20194, a clear indicator of the shrinking contribution of non-IT infrastructure, heating, cooling, lighting and others in a data centre’s energy consumption.
Going forward, advancements in cooling systems will take centre stage in energy-efficiency gains within non-IT infrastructure. Natural cooling, where cool ambient air or chilled water from nearby resources are used to cool the facility, will impact the geographical locations of data centres. In addition, an increased prominence of liquid cooling technologies will impact data centre cooling system designs. Meanwhile, in terms of IT infrastructure, the expanding need for IT equipment to operate at higher ambient temperatures will reduce the need for cooling per computing capacity.
It is anticipated that facility and energy professionals will spearhead comprehensive energy-efficiency plans covering IT and non-IT infrastructure to stay ahead of their peers in energy-efficiency gains.
1 Lima, J. M. (December 12, 2017). Data Centres Of The World Will Consume 1/5 Of Earth’s Power By 2025. Data – Economy. Retrieved from https://data-economy.com/.
2 Global data centre energy demand by data centre type. (January 7, 2020). International Energy Agency. Retrieved from https://www.iea.org/.
3 Pichai, S. (September 19, 2019). Our biggest renewable energy purchase ever. Google. Retrieved from https://www.blog.google/.
4 Lawrence, A. (May 2019). Is PUE actually going UP? Uptime Institute. Retrieved from https://journal.uptimeinstitute.com/.