'Only 26.3 Minutes of Downtime a Year': Why Top-Tier Data Centers Can't Remove Batteries Despite Fire Risks [News Seolcham]

UPS Prevents Power Outages and Blackouts in Data Centers
Essential for Uptime Despite Fire Risks
A Global Challenge?Firefighting and Safety Measures Needed

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Why can't data centers give up the internal installation of lithium-ion batteries, even though they pose a significant fire risk? As lithium-ion batteries have been identified as the cause of the recent fire at the National Information Resources Service (hereafter referred to as NIRS), which triggered a nationwide network outage, attention is now focused on why batteries containing flammable electrolytes must be placed inside data centers.

Data Centers Operate Year-Round-Batteries Are Essential

Lithium-ion batteries used in uninterruptible power supplies (UPS) for data centers. NPP Power website

The batteries installed inside data centers are components of uninterruptible power supplies (UPS). UPS units serve as emergency power sources, brought in to prepare for unexpected power outages within data centers.

If the power supply inside a data center is suddenly cut off, the UPS must activate within just 2 to 10 milliseconds (thousandths of a second) to deliver electricity to computer circuits. Once the backup generator is fully operational, the UPS returns to standby mode.

This is why the batteries, which serve as the energy storage system (ESS) for the UPS, must be located inside the data center. Since the success of the UPS is determined within a matter of milliseconds, the batteries need to be placed as close as possible to the data center equipment to maximize response speed.

Data centers, which house a variety of computer devices, must guarantee a high operational rate at all times. If an unexpected blackout or power failure cuts off the internet or results in the loss of valuable data for customers and businesses, the consequences can be immeasurable.

The metric used to measure a data center’s operational rate is called "uptime." The IT industry classifies facilities into four tiers based on their uptime. Even the lowest tier, Tier 4, must keep annual downtime below 28.8 hours out of 365 days. The highest tier, Tier 1 data centers, are allowed only 26.3 minutes of downtime per year. This is why a UPS is essential inside data centers, despite the fire risks.

UPS Fire Hazards Are a Global Issue-Fire Safety Measures Needed

This is not the first time a UPS has been identified as the cause of a data center fire. The fire at the SK C&C data center in Pangyo, Seongnam, Gyeonggi Province, which caused a massive outage of the messenger service KakaoTalk in 2022, also started with a battery fire in the UPS. Overseas, the risk of UPS fires remains a major issue. In May this year, a battery fire broke out at the Digital Realty data center in Oregon, USA, paralyzing global social networking services (SNS) including X (formerly Twitter).

On the morning of the 29th of last month, police officers were moving the lithium-ion batteries for the uninterruptible power supply (UPS) that had caught fire at the National Information Resources Service in Yuseong-gu, Daejeon. Photo by Yonhap News Agency

IT companies are responding to fire risks by enhancing fire suppression systems within data centers. One year after the fire, KakaoTalk established its own data center in Ansan, Gyeonggi Province, in 2023, equipping the entire facility with eco-friendly fire suppression gas systems and ensuring that emergency equipment activates immediately in critical situations. The area housing the UPS is also separated by fireproof barriers between the UPS’s various components and the batteries, so that even if a fire starts inside a battery, it cannot easily spread to other equipment.

In countries with larger data center markets than Korea, such as the United States, efforts are underway to develop alternative batteries that do not contain flammable materials. A representative example is the nickel-zinc battery. Unlike lithium-ion batteries, nickel-zinc batteries do not use flammable electrolytes, making them less prone to fire and more suitable for data center environments. Overseas manufacturers such as ABB and ZincFive are researching UPS systems based on nickel-zinc batteries.