Gordon Johnson, Senior CFD Manager at Subzero Engineering, addresses why data centres run the risk of becoming stranded assets, and explores measures that can be taken to avoid this outcome.
Data centres, particularly those handling HPC, are at constant risk of becoming stranded assets. Stranded assets can occur when facilities do not meet their designed capacity, are no longer economically viable due to changes in technology or business needs, or fail to contribute effectively to sustainability measures. In the context of data centres, this often relates to cooling challenges and the cooling capacity that the Information Technology Equipment (ITE) can’t use.
Power, space, and cooling are the main capacity parameters in the data centre. Stranded capacity is installed capacity that cannot be used to support the critical load. It refers to data centre resources that are not available for use. Unfortunately, most of the time, you don’t even know if you have stranded capacity or, if you do, how much there is.
While critical loads are expected to be renewed, refreshed, or replaced over the lifetime of the data centre facility, older, non-energy star certified, or inefficient servers that are still turned on but no longer being used, continue to use both power and cooling resources. It also includes excessive redundancy or low utilisation of the redundancy options, a lack of scalable, modular design, and the use of oversized equipment or legacy lighting and controls.
While many may plan for the update and evolution of the ITE, the mismatch of power and cooling resources versus the equipment requiring the respective power and cooling inevitably results in stranded assets.
Challenging the invisible ceiling
Every data centre has an invisible ceiling that limits the amount of ITE that it can cool. With the shift towards HPC data centres, facilities are even more challenged when it comes to having enough cooling capacity to match (and exceed) ITE cooling demand. As data centres become more power-intensive due to HPC requirements, the cooling infrastructure must keep pace.
Inadequate cooling can lead to increased operational costs, reduced efficiency, and environmental concerns. It’s a problem since it prevents data centres from meeting design capacity and also restricts them from becoming sustainable and energy-efficient. It’s also an expensive problem since wasted cooling energy is not contributing to the overall cooling of the ITE.
Stranded capacity is wasted energy, cooling unnecessary equipment, and lost cooling to areas that need not be cooled. Stranded cooling capacity can include bypass air (supply air from cooling units that is not contributing to cooling the ITE), too much supply air being delivered from the cooling units, lack of containment, poor rack hygiene (missing blanking panels), and unsealed openings under ITE with raised floors, just to name a few.
Combating the inefficiency
Releasing stranded capacity improves energy efficiency, reduces costs, and allows for increased data centre capacity without additional cooling equipment. To avoid becoming a stranded asset, organisations should conduct thorough assessments when building or upgrading data centre facilities. While the root cause of stranded assets is often due to operational issues and conflicts of management or space allocation, future scalability, energy efficiency, and identifying technology obsolescence must be considered with strategic changes or updates.
A lack of metering and metrics can contribute significantly to an inefficient data centre. To combat this, it’s highly recommended to use data centre monitoring software to help identify and eliminate wasted energy within the data centre white space. Monitoring and compliance with operational best practices can minimise the power and cooling imbalance effectively, but this needs to be an ongoing and continually updated process to reduce risk.
Realising the energy savings
Air management and control is a prerequisite to many energy efficiency measures. Wasted air is, after all, wasted money. Realising energy savings through correct air management can be done in two ways. First, physically rearrange the space to promote the separation of hot and cold air. While this measure by itself does not save energy, it does enable future savings to be made. Secondly, one of these two actions must be taken: increase the supply air temperature and/or decrease the supply airflow rate.
Other options for energy savings include removing server waste. Idling or unused servers can consume up to 60% of full power while delivering no tangible output. Under-utilised ITE can be consolidated, saving space and optimising the utilisation of the ITE that you do need. Virtualisation may be the most powerful of consolidation approaches. It consolidates applications from under-utilised ITE onto fewer items and better-utilised hardware.
Some organisations opt for colocation or cloud-based solutions to minimise the risk of stranded assets by outsourcing their data centre needs to providers that specialise in maintaining infrastructure.
In summary
Addressing the challenge of the stranded asset is vital for ensuring the industry remains both sustainable and economically viable while laying the financial foundation for its long-term future. It makes no sense to allow ITE to take up space that’s either not being used, consumes power but gives nothing in return, or indeed utilises energy that affects and upsets the environmental equilibrium.
