How Amazon Rewired Its Data Centers After Mississippi Power Warning

Earlier this year, officials at Mississippi electric utility Entergy had some worrisome news for Amazon: It was going to have to start kicking the company’s Mississippi-based data centers off the grid during peak times to ensure it could support other customers, according to two people with knowledge of the situation.

Amazon’s cloud unit, Amazon Web Services, operates one data center near Jackson, Miss., which it is expanding, and it is building two more data center facilities in the same general area, making the state an important region in its data center buildout. Utilities rarely kick off major customers, but Entergy’s message, which hasn’t been previously reported, reflects how soaring demand for power from AI cloud operators is forcing power companies to take unprecedented measures to balance the needs of their various customers.

Entergy’s message prompted AWS to introduce changes to the automated system it uses to switch its data centers from the grid to backup power like gas-powered generators, the two people said. In a new system, called Project Falcon, Amazon introduced measures that allows the utility on its own to trigger the data center to switch to backup power from the grid, one of the people said—freeing the utility of the need to contact AWS to initiate the change.

“Data centers are so giant, they’re pushing the capabilities of what the grid can do and how fast it can do it, so grid operators and utilities are putting special rules on these guys,” said Mike Sloan, CEO of Synergetic, a power provider to data centers. “[Data centers] have to accept some curtailment, which means then the data center has to have a toolbox that can handle that risk.” (Curtailment is the industry term used when utilities tell customers to either cut back their power consumption or get off the grid entirely).

While Project Falcon was developed for AWS’ Mississippi data centers, Amazon may end up using it elsewhere in the U.S., one of the people said.

Utilities across the country are warning they may have to kick data centers off the grid at times. Last year, the Texas Legislature passed a law allowing grid operator ERCOT to force its large customers to curtail their usage of the grid under certain conditions.

In North Carolina, power provider Duke Energy has recently added new provisions to contracts with large customers, allowing it to kick them off the grid when necessary, according to a spokesperson. PJM, the largest grid operator in the United States, which manages electricity for several states including parts of Virginia and Illinois, has asked federal regulators for permission to kick large customers off the grid in emergencies, before other customers, among a series of measures to PJM has proposed to help it solve a power capacity shortfall. (PJM needs federal permission because its customers are utilities across various states.)

Other cloud providers have devised their own systems that can help spare an overloaded grid. Google, for example, has focused on reducing how much its data centers use utilities that might be overwhelmed. Through a process it calls “demand response,” Google can redirect workloads to data centers in regions with more available electricity.

Earlier this year, Google said it signed agreements with five utilities under this framework. Through those agreements, Google is committing to give up using up to 1 gigawatt of grid electricity should the utilities need to deploy it elsewhere.

Nuclear Efforts

As the AI boom drives a massive expansion of data centers across the U.S. and globally, securing power for the new facilities has become one of the biggest bottlenecks. AWS, as the world’s largest builder of data centers, has been aggressive in devising new ways of getting power—including with solar panels, batteries and nuclear energy, in addition to natural gas power plants.

At the end of September, Constellation Energy said a deal with Amazon would help pay for a $3 billion, 190-megawatt expansion of its nuclear facility in Maryland. Constellation Energy will also power Amazon’s data centers in the PJM region.

Amazon says it views the data center buildout as a way for big companies to help finance additional capacity for the power grid, including in Mississippi, and give utility companies the certainty they need to invest in upgrades. The company also said that utilities in multiple regions have the ability to remotely prompt Amazon to use backup generation for its data centers.

“We work closely with utilities to support grid reliability while ensuring our customers have the resilient infrastructure they depend on,” an Amazon spokesperson said. “As we grow, we’re also investing in newer, cleaner technologies and working with utilities to bring new generation and infrastructure to the grid.”

An Entergy Mississippi spokesperson said it can require that all customers, including data center customers, reduce their use of the grid when demand exceeds Entergy’s available supply.

“Our data center customers—including Amazon Web Services—are obligated to install necessary equipment to protect the power grid from power quality issues that can occur due to the size of their electric load,” a spokesperson said. “We work extensively with [data center customers] to ensure that enough new power generation capacity and appropriate transmission upgrades are added to the system to reliably supply additional demand on the grid while maintaining reliable service to our existing customers.”

Alternate Sources of Power

When cloud firms have to resort to backup power, many use diesel-powered generators. But federal regulations limit data centers from using diesel generators to 100 hours per generator per year in non-emergency situations.

Getting approval to expand generator use has proved difficult. Last year, the Minnesota Public Utilities Commission ruled against Amazon’s attempt to use 250 generators tied to a data center in Becker, Minn. Amazon abandoned plans to build the data center. Minnesota also at the time was weighing new laws that would end some tax breaks around building data centers.

Amazon says that it runs its backup generators minimally, primarily for testing and maintenance. The company also said its use of generators is still subject to regulations, including state permits, and those permits still hold regardless of Amazon’s energy arrangement with a utility.

Amazon has studied the feasibility of using other backup sources of power, including batteries, according to someone with knowledge of the efforts.

But utilities are wary of batteries, worried about the power that batteries will draw from the grid when they charge. A year and a half ago, Amazon began conversations with Dominion, the energy provider in Virginia, about using batteries as a backup and has so far not gotten anywhere, according to a person involved in the conversations.

A sticking point is that Dominion is concerned about the possibility that AWS would undertake the power-intensive process of charging large backup batteries during peak-usage times, the person said, potentially overloading the grid. To use that much power, Amazon would have to pay for upgrades to its own electricity system which would be too expensive to make the idea worth it for Amazon, the person said. Amazon argues that it is willing to never charge its batteries at peak times. But Dominion has taken a more risk-averse approach, the person said.

A Dominion spokesperson said it does not comment on specific customer projects. “Dominion Energy and Amazon have been business partners for a long time,” the spokesperson said. “As part of this partnership, the two companies work on common infrastructure issues to ensure grid reliability.

Other states are on board with the battery effort. Two years ago, Amazon unveiled a new battery power system in Southern California. Several Amazon facilities in the area, including data centers, were getting power from solar panels, and the battery power helped ensure the facilities were using energy free of carbon even after sunset or when the sun was obscured by clouds. Like Project Falcon, the system was able to automate the process of switching between power sources, though this project was more motivated by sustainability concerns than AI data center-fueled power shortfalls.

Amazon has also bought a power plant of its own, in Pecos County, Texas, that would power a data center in the area, its first data center powered completely off the grid, energy research firm Cleanview first . The facility, which is called GW Ranch, received a permit from the state of Texas allowing it to emit 33 million tons of carbon dioxide, more greenhouse gas than the largest coal plant in the United States, though Cleanview notes companies rarely emit the full amount their permits allow. Amazon has also bought a solar farm and battery storage system in Oregon, which is still connected to the grid, said Michael Thomas, Cleanview’s CEO.

“Before the launch of ChatGPT, [Amazon] could find a plot of land, make sure it had water, fiber, it was near power lines….it was just a really standard process,” Thomas said. “It’s gotten slower, it’s gotten more difficult, and it requires a lot more infrastructure.”