Data centers have been at the forefront of battery technology for decades. Their sophisticated battery systems are vital for ensuring the continuous delivery of energy in the event of disruption to the primary power supply. As facilities have pushed the boundaries of energy efficiency in recent years, they have begun to explore new alternatives to existing battery technology that could allow them to become even more reliable, cost effective, and environmentally conscious.
How Do Data Centers Provide Power?
The average data center has immense power requirements. Not only must it provide electricity to power row upon row ofserver cabinets, each of which might contain as many as 42 servers, but the facility must also power the cooling systems and environmental controls that manage the heat generated by all of that IT equipment. There’s also the various infrastructure monitoring systems to consider, as well as security measures and basic power needs like lighting.
Data centers tap into the local electrical grid to meet these power needs. Many facilities have more than one feed to provide some measure of redundancy, but under normal operating circumstances, a data center is powered entirely by electricity drawn from the local grid. This is the best way to provide uninterrupted power under most conditions, but as the widespread grid failures across Texas in early 2021 demonstrated, data centers need to have a backup system in place to provide emergency power when the grid goes dark.
Why Are Batteries Important for Storage and Power?
Data center backup systems have long relied upon a two-stage backup system that utilizes batteries and diesel-powered generators. While it may seem odd that such high-tech facilities depend on a technology as old as diesel power, the fact remains that diesel generators remain the most cost-effective and reliable means of delivering emergency power over a sustained period of time. This has made them the go-to standard for backup power for decades.
But diesel generators alone can’t provide uninterrupted power in the event of an outage. That’s because it takes several minutes for them to start up and begin generating electricity. To cover that gap, data centers utilize battery-powered uninterruptible power supplies (UPS)that can deliver enough energy to keep the facility running until the backup generators can take over. Since the battery systems can provide power instantly, they’re an ideal “ride-through” solution that springs into action the moment the primary electrical supply fails to keep the data center operational.
Current Data Center Battery Technology
The most common data center batteries are valve-regulated lead acid (VRLA) cells that are integrated in large cabinets designed to power the facility’s UPS systems. Various types of lead acid batteries have been used in data centers for decades due to their relatively low costs and ease of use. Most battery systems use modular cells that are easy to replace without any specialized training.
Unfortunately, they also need to be replaced quite frequently. Although manufacturers claim that lead acid batteries have a standard predicted life of about ten years, their actual service life is closer to three to five years. They also take a long time to recharge and store less power over time as they age, delivering only about 85 percent power efficiency.
Lead acid systems have a large footprint in terms of infrastructure, often taking up several rooms and requiring reinforced floors when stored above ground level. They are also highly sensitive to environmental conditions and need to be kept around 68 degrees Fahrenheit for maximum efficiency. That translates into higher cooling and environmental monitoring costs, which increases the overall cost of ownership for these systems.
5 Innovations in Data Center Battery Technology
Given the limitations of existing battery backup systems, data centers have been exploring new battery technologies that could provide more efficient and environmentally friendly ways of delivering power in the event of an outage.
1. Lithium-Ion Batteries
By far the biggest innovation in data center battery technology has been the rapid development of lithium-ion batteries. The cost of lithium-ion based cells has come down significantly over the last few years, which has made them a much more attractive alternative to outdated lead acid batteries. Lithium-ion batteries are able to deliver more power at lighter weight, which translates into a smaller footprint from an infrastructure standpoint. They also provide the same energy efficiency at 86 degrees Fahrenheit as lead acid batteries do at 68 degrees, so they provide day-to-day operational savings on cooling costs. With an energy efficiency of 99 percent, faster charge times, and a service life of about seven years, lithium-ion batteries have the potential to provide much better performance over time.
2. Nickel-Zinc Batteries
While lithium-ion batteries have received the most attention in recent years, they’re not the only alternative battery technology in development today. One of the problems with lithium-ion batteries is thermal runaway, which is caused when the heat generated within the battery exceeds its ability to disperse it safely, resulting in a chemical reaction that suddenly releases all of the energy stored in the battery. The resulting fire caused by thermal runaway is chemical in nature and extremely difficult to extinguish, as evidenced by the four days it took firefighters in Australia to control a battery fire at a Tesla storage site in 2021.
Nickel-zinc battery technology isn’t as mature as lithium-ion systems, but as an aqueous solution, it can’t be taken to thermal runaway. This is a critical advantage, especially given that many municipalities and insurers require facilities to comply with strict safety codes to mitigate the risk of fire. Nickel-zinc systems can provide as much energy density as lithium-ion systems and have comparable cooling needs, so they may eventually prove to be an ideal alternative.
3. Battery-Grid Integration
Data center engineers at Google and Microsoft have both been working on new battery technologies that not only deliver more backup power at a smaller footprint, but also integrate into the local electrical grid. One of the enduring challenges with data center batteries is how to manage them when they’re not in operation. By integrating the batteries with the local energy grid, they could be used to store excess power generated by renewable energy systems. This could not only ensure a steady supply of backup power for the data center, but also provide a potential new revenue stream by offering storage services to local electric companies.
4. Long-Haul Battery Backups
While most facilities still rely on batteries as a “ride through” solution that provides power only until the diesel generators are up and running, battery technology has advanced to the point where it may be possible to replace those generators with large scale battery deployments. Google recently deployed such a system at a hyperscale facility in Belgium as part of its effort to reduce its reliance upon dirty energy sources like diesel fuel. Given that most outages are relatively short-lived, increasing battery ride-through times from 10-15 minutes to several hours could drastically reduce the need for diesel generators. Some researchers even think battery backup systems could eventually provide uninterrupted power for 18 to 24 hours.
5. Software-Based Backups
While not strictly a battery technology, many providers have looked at shifting IT workloads between integrated data center sites as a more efficient way of ensuring uptime. By taking a geodiverse colocation strategy, they can keep data and applications available by backing up systems across multiple data center locations. This ensures that even if one data center goes down for any reason, workloads can be shifted elsewhere within the integrated network. Implementing this form of software-based redundancy will be critical as various data center locations undergo improvements to their battery backup systems.
Get Reliable Uptime with vXchnge Data Centers
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About Ernest Sampera
Ernie Sampera is the Chief Marketing Officer at vXchnge. Ernie is responsible for product marketing, external & corporate communications and business development.