Some of the best businesses in the world are successful because they know how to sweat their assets: maximizing the amount of work they get out of their major investments in property, plant, machinery and, naturally, staff.

Yet in the data center sector some of the most vital infrastructure assets often play a marginal role on a day-to-day operational basis. For example, the backup engines and UPS, which form part of a highly redundant architecture, may only fully come into play when anything from anomalies in the power supply to a full-scale emergency occurs.

But perhaps there are ways such major investments can be profitably put to work for the operator, while helping utilities more efficiently and cost-effectively run their power grids?

That idea forms the basis of Eaton’s data centers as a grid concept, in which the data center, instead of being a passive consumer of grid power, provides critical power services to help utilities tackle their grid balancing and other challenges, which have become more acute in recent years with the shift towards renewable energy sources.

These services include what is called ‘peak shaving’, frequency and voltage regulation, virtual inertia, and fast frequency reserve (FFR) services.

“It's all about transforming the assets that the data center already has, or could have in the future, to be more interactive with the grid,” says Forrest D. Secosky, commercial marketing manager, data centers, at Eaton.

He continues: “For instance, data center facilities have a range of storage assets, such as UPS or battery, and energy storage. Increasingly, they might also have alternative ways to generate power, such as a microgrid incorporating solar or wind. Most will have diesel or gas generators for backup, too.”

These could act as either a system reserve or a fast-frequency response mechanism, without compromising their primary purpose for the data center. Indeed, the data center operator could set the parameters for which the UPS provides power to the utility for grid services, ensuring they always retain sufficient back-up capacity to handle pretty much any emergency that may arise.

“So there's a multitude of ways that a data center could participate in either the power generation to support their own operations or sharing that power back with the utility to help manage the ups and downs of demand on the grid,” Secosky adds.

It’s not just the vagaries of minute-by-minute demand from consumers that utilities are grappling with, but the even harder to predict perturbations in supply wrought by the roll-out of renewables, particularly in the form of wind and solar. So much so, that the cost of balancing power grids has gone through the roof.

In the UK, for example, shrinking baseload power as coal and nuclear plants have closed has seen grid balancing costs balloon from £1.2 billion ($1.5bn) in 2019 to more than £4 billion ($5bn) in 2022 – and with further closures of both looming in the coming years, those costs are not going to be coming down.

Hence, the provision of grid balancing and other power services will not only enable data center operators to put their investments towards increasingly profitable work, but should also help contain those costs as more coal and nuclear power plants are closed for good – a classic win-win.

“It all comes down to the energy they have on site, and the batteries – the UPS – in particular,” says Secosky. “There’s usually plenty of additional capacity built into the system just because of the minimum sizing requirement of the UPS.”

After all, for safety’s sake – perhaps a fault means that the backup engines don’t automatically start-up as intended – there’s typically a large margin of error built-in to the calculations when UPS and backup engines are specified prior to installation. In addition, they are typically over-specified in order to cover the very worst-case scenarios, so there is always plenty of unutilized capacity to spare.

Moreover, while it may take standard diesel backup generators no more than a minute, at most, to take over the running of the facility, the UPS infrastructure is typically designed to be able to keep things ticking over for five or more minutes. But data center operators will need to make a few investments in their next round of upgrades in order to be ‘grid ready.’

Battery power!

This will mean upgrading UPS systems from old-style lead acid batteries to Lithium-ion as valve-regulated lead acid (VRLA) batteries are not designed to handle the number and frequency of cycles, and the longer service life these new grid-interactive services will entail.

“Historically, VRLA batteries have been most popular. There’s now a lot of new battery chemistries available, but our focus at Eaton is primarily on Li-ion, at the moment, because of the sheer number of charge and discharge cycles possible with Li-ion compared to lead acid,” says Secosky.

“As a result, more and more UPS systems are being shipped with Li-ion batteries these days, which can be leveraged in this way.”

Lead acid batteries, by contrast, are considerably less flexible. While they can be adapted to support Fast Frequency Reserve services, due to the small amount of activation and short discharge required, it’s not possible to provide the full gamut of potential services. “You’d wear out the batteries. But on the other hand, Li-ion batteries today are probably not being cycled as much as they could be,” says Secosky

While the upfront cost of Li-ion batteries is greater, their overall total cost of ownership is ultimately lower, adds Secosky.

On top of that, of course, data center operators will need to ensure that their UPS can support the provision of grid-balancing services, and that their data center software is capable of handling the interface between the facility and the power grid.

Eaton’s latest UPS systems can be equipped with EnergyAware firmware built-in, which means that it is actively ready to provide grid balancing and other services to the grid – and already tried and tested across North America, Ireland and Scandinavia. When paired with the company’s Brightlayer Data Centers suite, data center operators can automate responses to grid anomalies, such as peak demand occurrences or frequency response issues.

The EnergyAware algorithms mean that data center operators can allocate a specific portion of the stored energy in their UPS system for these services, but they always retain overall control.

For the grid operators, on the other hand, such grid-interactive infrastructure is akin to a virtual machine that they can spin-up under particular conditions, backed by a pre-defined agreement with the data center facility. The Brightlayer Data Centers suite coordinates and documents these actions for regulatory compliance and financial reporting.

Giving back

While grid balancing is currently the number one service grid operators need, in the future, new applications could contribute even more, suggests Secosky.

This could even, perhaps, invert the current dynamic in many parts of the world where data center organizations need to wait until the grid operator is able to provide sufficient capacity before they can open or expand a facility, to one where the operator can provide on-site generated power to the grid, enabling them to open and operate regardless.

There is another element, too, that also needs to be addressed, admits Secosky: grid balancing services also need to be supported by the power utilities and that entails investments in grid upgrades on their part.

This is where utilities in the EMEA region, beset by some of the highest power prices in the world in recent years, have taken a global lead, he adds, but much of the work required to support grid-interactive services is already being done in order to support renewable power. Moreover, a number of data center operators have also been exploring these capabilities in partnership with Eaton.

So in the future, believes Secosky, new data center developments can – and arguably should – be constructed with grid-interactive capabilities built-in at the design stage, not just for perfectly sensible financial reasons, but to support sustainability throughout the lifecycle of the data center’s UPS infrastructure, too.

For more on how Eaton is helping optimize data centers for the digital, low-carbon future, visit Eaton.com/DataCenters