The global demand for data has seen near-exponential growth, fueled by the pandemic. When many of our jobs moved online, the demand for data increased dramatically. Since then, we’ve added unpredictable workloads, 5G build-outs, and the rise of AI, and this demand continues to grow.

It’s no surprise that both colocation and enterprise data centers are forecasting enormous growth in the coming years, a CAGR of over 14% between 2022 and 2030. The wrinkle? Reliable power. To quote right from the horse’s mouth, the Department of Energy states, “Much of the U.S. electric grid was built in the 1960s and 1970s. While the system has been improved with automation and some emerging technologies, our aging infrastructure is struggling to meet our modern electricity needs.”

By 2030, data centers in the U.S. may be drawing over 350 terawatt hours of power. Our power grid can’t handle this in its current state.

Enter Microgrids

The national U.S. grid is the “macrogrid.” “Microgrids” are small, local- or even business-level grids meant to support only that small area. They’re sometimes partially connected to the macrogrid and sometimes totally separate, and they are often powered by renewable sources.

Microgrids are desirable because they are more controllable. Operating on a smaller scale lets the operator decide the electricity source(s) to cut or eliminate CO2 emissions if they want, minimize line losses, plan for future capacity and scaling, and enhance resiliency by bypassing macrogrid congestion or outages.

These aren’t a new concept. The National Renewable Energy Laboratory and organizations like it have been helping develop microgrids since the early 2000s. What is new is the extent to which they’re likely to boom in the mission-critical sector in the coming years. Due to their huge demand for power, data centers could be at the forefront of microgrid power buildout, but other mission-critical facilities such as hospitals, defense, airports and seaports, food and water processing, waste processing, and more are likely to adopt microgrid power in the near-term.

But investing in this emerging mission-critical technology will be a waste without the proper backup in place.

Battery Technologies for Microgrid Backup

Every mission-critical industry has its preferred Uninterruptible Power Supply (UPS) and many choose a Battery Energy Storage System (BESS) for longer outages or when grids take longer to stabilize. A standalone BESS is pretty much a non-starter for mission-critical industries looking into microgrid power due to limited autonomy. As designed, the power will flip over to the BESS during grid instability or an outage with zero interruption or issue. But in practice, that’s not always how it works out. And some BESS solutions have other “side effects.” Let’s look at some of the rapidly expanding battery technologies that are backing up microgrid power.

Traditional Batteries

Diesel generators and lead-acid batteries were the de facto standard for decades because they were the only commercially available options. These came with obvious environmental drawbacks, in addition to being bulky and noisy. To be effective in a BESS, mission-critical facilities also need quite a lot of them. This means not only more maintenance and repair work but, for diesel generators, it also means careful coordination to ensure all the generators turn on together when a power event occurs. Lead-acid batteries require a bit less orchestration, but they are less efficient when power must be discharged rapidly and have a relatively short lifespan.

Lithium-Ion

Lithium-ion batteries came onstage in recent years with improvements over some traditional battery shortcomings. These batteries can offer a much longer lifespan and higher energy density than lead-acid and are lower-maintenance and lower-pollution than diesel generators. They can be more efficient and versatile than traditional options.

But lithium-ion batteries aren’t a magic bullet. The biggest drawback to these batteries is safety, as lithium-ion batteries can be induced to thermal runaway and catch fire. Mission-critical applications assume no small risk when trusting a lithium-ion BESS, which have been implicated in some high-profile data center fires in the last few years. As a secondary concern, lithium-ion batteries are produced with geopolitically fraught minerals, including cobalt, which have implications for human rights. Combined with their extremely long, risky, and questionable supply, lithium batteries fail to meet many firms’ ESG and local sourcing requirements.

For decades, traditional batteries were the only option. Lithium-ion is now seen as a viable option because it is better than its predecessors. But it’s not the only game in town. Backing a microgrid with a highly flammable technology is a risk that many mission-critical facility operators won’t take. That’s why researchers continue to develop other battery technologies that push the boundaries of sustainability and safety.

Fuel Cells

Hydrogen fuel cells have been proposed and tested as a potentially sustainable alternative backup battery system. These fuel cells have high energy density and near zero emissions, so – in theory – they’re an ideal BESS battery for a microgrid powered completely by renewables.

The trouble with hydrogen fuel cells is that, essentially, we’re not there yet. The production of hydrogen is such an intensive process that, ironically, it often requires natural gas. Hydrogen is also hard to store once it’s produced. And because the hydrogen fuel cells have a slower start-up (not ideal for something as nanoseconds-critical as backup power), they’d need to be paired with another battery or supercapacitor to function properly, essentially defeating the purpose.

Flow Batteries

Flow batteries, which store energy in fluid electrolytes that “flow” through the battery’s electrochemical cell, are another battery technology. These come in many forms, including VRFBs, Zinc-Bromine, and a very creative, highly sustainable version.

Where there’s metal, there’s rust. Iron oxide is readily available. Chemists figured out how to turn this plentiful resource into iron flow battery technology. These batteries don’t use conflict minerals, have a long life cycle, and cannot be induced to thermal runaway, making them a sustainable, safe complement to a microgrid.

The main drawback to flow batteries, like fuel cells, is their comparatively slow discharge speed. When responding to dynamic loads and when fractions of fractions of seconds matter, this may pose a major risk.

Sodium-Ion

Sodium is bountiful all over the world—a big reason why sodium-ion battery research is gaining momentum. It’s a truly sustainable, conflict-free material supply. The chemistry is showing excellent results: around four times higher power-per-energy than lithium-ion, full recharge in a quarter of the time, and five times more deep discharge cycles. And essential to microgrid backup power is that sodium-ion batteries can immediately discharge without warm-up, and are completely nonflammable, even if punctured. Immediate power supply, zero fire risk.

Sodium-ion batteries like Natron’s Prussian blue chemistry enable new microgrid architectures that are more reliable, more resilient, and more responsive than those backed by other battery technologies.

Batteries: A Critical Choice

Mission-critical facilities that rely on uninterrupted power need a truly uninterruptible supply. We all know examples of when the mission was jeopardized: the Ever Given blocking the Suez for six days. AT&T’s half-day total network outage. Hospitals running on generators after severe storms. Downtime can have serious—in some cases, life-threatening—consequences. Microgrids are very likely the next frontier for keeping mission-critical industries supplied with reliable power. These power structures should be protected with a battery technology that ticks all the boxes: meeting or exceeding power needs, made from abundant, sustainable resources, and ready to deploy now.

Jack Pouchet is the Vice President of Sales and Marketing for Natron Energy. Jack works closely with major OEMs, large Telecom and data center owners and operators, BESS/ESS integrators, industrial power users driving towards decarbonization, and leading mission-critical engineering firms to help define, architect, and create opportunities for advanced battery and power technologies that improve day-to-day business and operational efficiencies. Jack brings over twenty years of related OEM power supply, power generation, distribution, and power product sales and marketing experience to Natron giving him a unique end-to-end perspective of the entire AC and DC power path.