Three ways nickel-zinc batteries enhance data center reliability

In a hyper-connected, technology-reliant world, data centers have gone far beyond indispensable — they are vital infrastructure, without which modern life grinds to a halt. They connect billions of devices to countless systems, ensuring critical tools are available around the clock for everyone from individual consumers to governments to the largest companies in the world.

With power reliability in the U.S. expected to decline over the next decade and power disruptions already responsible for 43% of data center outages, the need for robust, on-site power reliability solutions cannot be overstated. Modern nickel-zinc (NiZn) chemistries are an exciting opportunity to improve the reliability of data centers and to do so through a variety of different services and solutions.

1. Centralized UPSs

During an outage, data centers need to maintain operations while waiting for their backup generators to kick in. Although the time between the initial outage and the generator services could be as short as a few minutes, a loss of power during this period could be devastating for data centers and can cost operators anywhere from $100,000 to millions. To ensure continued operations during these short gaps in power, mid- and large-size data centers rely on centralized UPSs.

These UPS systems power data centers and offer a bridge service between normal operations and backup generators. While this role may seem small, among power-related outages, 53% were caused by a failure of the UPS. And while data center UPS systems are most often powered by lead-acid batteries, UPS systems that utilize NiZn battery technology have specific advantages over lead-acid in terms of performance, reliability, safety, lifetime cost and climate impact.

NiZn batteries have higher power density than lead-acid batteries, the traditional standard battery in the data center, so by choosing NiZn battery backup, data center designers can reduce the footprint needed for energy storage. They are also safer, as NiZn batteries do not exhibit thermal runaway and are, thus, nonflammable. In terms of reliability, when a lead-acid or lithium-ion battery cell fails, it creates an open circuit that halts string operation. On the other hand, a weak or depleted NiZn cell remains conductive and allows the string to continue operating. NiZn solutions also lower operating expenditures as they require simple maintenance and have a long useful life span. And, finally, NiZn batteries have the best climate impact score — 9.4 out of a possible 10 — of backup battery chemistries typically used in data centers, according to a recent climate impact report.

2. Generator starting

While UPSs meet immediate, short duration needs during an outage, should the power remain out longer, data centers will turn to longer duration backup, most commonly provided by a diesel generator. These industry-standard solutions can power data centers on stored fuel for several hours or even days. With regular access to fuel replenishment, the number of days could increase to weeks. Each generator relies on batteries to crank and start, which is the role taken by a battery-powered generator starter.

One of the main problems with emergency generators is starting battery failure. Lead-acid starting batteries on gensets are replaced every one to three years, and can fail suddenly, without warning. The power needs of data centers can be massive, sometimes requiring a number of generators, each featuring their own starters

High-power density Ni-Zn batteries excel in this application, as they require minimal space — only two batteries are typically required per generator — and are suited to endure stress. Similar to their use in UPS systems, NiZn batteries in generator starters offer unparalleled power delivery, smaller footprint, higher reliability, lower maintenance, and major sustainability advantages compared with alternative battery chemistries.

3. Rack-level battery backup

Hyperscale data center design has moved to rack-level battery backup to overcome some of the challenges inherent to centralized backup — excess heat and conversion losses. As data centers take alternating current (AC) grid power and perform double conversion (AC-DC-AC), energy is lost in the form of heat. This is not an issue on a small scale, but the losses are considerable at hyperscale data centers, as is the added heat. Any avoided heat is a win in a sector already challenged by high cooling loads. These losses, coupled with added cooling demands, drag down energy efficiency.

In response, hyperscale data centers are increasingly adopting DC power distribution architectures at the rack level rather than pure AC. When using DC distribution, backup power can be provided by rack-level battery backup units (BBUs) installed within each rack of IT hardware. This approach can improve reliability because an issue with any one BBU only affects a single rack, while a centralized UPS approach can impact a variety of downstream equipment.

This fresh approach demands a battery with a smaller footprint, high safety standards, and affordable costs. Ni-Zn checks all of these boxes. When it comes to in-rack DC back up, Ni-Zn is an ideal choice to meet the energy efficiency and reliability goals of distributed BBUs in data centers. Its high power density meets escalating rack power needs, while it performs reliably with minimal maintenance across a range of temperatures. It is safe to operate next to servers and around personnel, and it enhances data center sustainability because of its environmentally friendly constituents and recyclability.

Steve Jennings

Steve Jennings is vice president at ZincFive. He leads the sales and marketing organization and brings 24 years of executive experience in technology companies serving the energy, clean tech, communications, computing, and semiconductor industries. He is focused on providing superior performing, safe, and green energy storage solutions based on nickel-zinc batteries to mission critical applications in the data center and IT markets.