Data centers should sell spare UPS capacity to the grid

The energy storage capacity in uninterruptable power supply (UPS) batteries, languishing often dormant in data centers, could provide new revenue streams for those data centers, says Eaton, a major electrical power management company.

Excess, grid-generated power, created during times of low demand, should be stored on the now-proliferating lithium-backup power systems strewn worldwide in data centers, Eaton says. Then, using an algorithm tied to grid-demand, electricity should be withdrawn as necessary for grid use. It would then be slid back onto the backup batteries when not needed.

The concept is called Distributed Energy and has been gaining traction in part because electrical generation is changing—emerging green power, such as wind and solar, being used now at the grid-level have considerations that differ from the now-retiring, fossil-fuel power generation. You can generate solar only in daylight, yet much demand takes place on dark evenings, for example.

Coal, gas, and oil deliveries have always been, to a great extent, pre-planned, just-in-time, and used for electrical generation in real time. Nowadays, though, fluctuations between supply, storage, and demand are kicking in. Electricity storage on the grid is required.

Eaton says that by piggy-backing on existing power banks, electricity distribution could be evened out better. The utilities would deliver power more efficiently, despite the peaks and troughs in demand—with the data center UPS, in effect, acting like a quasi-grid-power storage battery bank, or virtual power plant.

The objective of this UPS use case, called EnergyAware, is to regulate frequency in the grid. That’s related to the tolerances needed to make the grid work—the cycles per second, or hertz, inherent in electrical current can’t deviate too much. Abnormalities happen if there’s a suddent spike in demand but no power on hand to supply the surge. 

Often, not much power will need to be removed, just “micro-bursts of energy,” explains Sean James, director of Energy Research at Microsoft, in an Eaton-published promotional video. Microsoft Innovation Center in Virginia has been working with Eaton on the project. Those bursts are enough to get the frequency tolerances back on track, but the UPS still functions as designed.

Eaton says data centers should start participating in energy markets. That could mean bidding, as a producer of power, to those who need to buy it—the electricity market, also known as the grid. Data centers could conceivably even switch on generators to operate the data halls if the price for its battery-stored power was particularly lucrative at certain times.

“A data center in the future wouldn’t just be a huge load on the grid,” James says. “In the future, you don’t have a data center or a power plant. It’s something in the middle. A data plant,” he says on the Eaton website.