Planning the future of America's vast electric grid

America's electric grid is one of the largest and most complicated pieces of infrastructure ever built. It is intended to deliver electricity nearly 100% of the time in any situation. The electric grid must be resilient, secure, cost-effective and equitable. This means that the grid must be able to operate under a wide variety of different scenarios, including normal operating conditions as well as during disasters. Additionally, the grid must produce electricity inexpensively, and in theory, provide electricity to everyone equally.

Managing tradeoffs while maintaining those four key characteristics is really difficult, said Mark Petri, director of the Electric Power Grid Program at the U.S. Department of Energy's (DOE) Argonne National Laboratory.

Petri noted that America's power grid was initially conceived in the early 20th century to distribute power unidirectionally from plants powered by fossil fuels to buildings and residences.

Recently, as electric cars have entered the landscape, scientists and grid operators have encountered an additional challenge and opportunity. Electric cars and their batteries can form two-way connections with the grid, both drawing power to charge but also potentially supplying energy back to the grid. The electrification of America's transportation sector will represent a huge additional source of demand on the grid for which operators will need to prepare, Petri said.

Electric vehicles will not be the only new source of demand for electricity, Petri explained. "You think of not only electric vehicles but also industry changing out natural gas for electricity for heating and manufacturing or data centers for artificial intelligence or cryptocurrency mining—these things require huge amounts of electricity that has never been needed before."

All these systems have multiple interconnection points at which the grid interacts with other infrastructure.

"We're not just looking at the electric power grid in isolation, but how it intersects with natural gas and telecommunications. We want to see how it interacts with our critical infrastructure, and through that we're able to look at how interdependent systems behave in both normal and abnormal conditions," Petri said. This way, he said, researchers can understand the potential implications of and strategies for mitigating risks to the grid system, whether they're natural (as in the case of extreme weather) or man-made (like a cyberattack).

Contributions to Argonne's grid research come from over 100 scientists and engineers working in basic and applied science, in areas that include nuclear energy, decision science, computational science, materials and systems analysis. The laboratory's approach is to understand and evaluate infrastructure; translate knowledge gained into practical technologies that solve grid challenges; and collaborate with industry and government to take action.

Balancing act: Daily challenges and long-term strategies of grid management

Argonne has several aims when it comes to long-term management of the grid—understanding it, translating and collaborating with different partners and entities. These must be balanced with the grid's more immediate challenges.

First, the grid must be operated. It must do the day-to-day or moment-to-moment work of balancing the demands on it.

"At any moment, you could have new demands on the system, like people plugging in their air conditioners in the summer or plugging in electric vehicles in the afternoon," Petri said. "You need to be able to anticipate those demands and respond quickly so that you don't have cascading failure."

Second, the grid must be planned. "Grid managers need to be able to think ahead. Where are we going to be in five years, or in 10 years?" Petri said. "What are the new technologies that will be coming online and what are the environmental conditions going to be like? How are we going to keep the system reliable, equitable, sustainable and secure?"

Third, grid disruptions must be prevented and managed. In addition to conducting risk analyses with other agencies, Argonne works with the DOE to respond to incoming hurricanes and assess their impact on the grid. Argonne also works with system operators to walk them through hypothetical emergencies.

"Being able to optimize the restoration of the grid if and when it is impacted by a big storm is extremely helpful for planning and helping communities," Petri said.

One big disruption event in which Argonne played a role in helping a community to recover was the 2017 Hurricane Maria that totally shut down the grid in Puerto Rico and left millions without power for almost a year. Argonne was one of the first groups to travel to the island after the storm on behalf of the Army Corps of Engineers and FEMA to assess the damage to critical infrastructure.

After the storm, Argonne began working with the local utility in Puerto Rico to help it be better prepared for the next extreme event. Argonne identified the most critical pieces of infrastructure that needed electricity as soon as possible and helped direct investments of relief and recovery funds to the appropriate parts of the island.

"We couldn't do everything we wanted to immediately, so we needed to figure out how to prioritize," Petri said. "Argonne tools were used to figure out what would be the best options for adding new generation near the population centers of the island, so even if transmission lines were to be knocked out by another storm, you could get power to where it's needed instead of having to transport it long distances."

Argonne researchers looked to see what level of new generation would be able to cost effectively minimize the number of power outages.

The effort in Puerto Rico has become the basis for a new grid-related platform called the North American Energy Resilience Model, which involves a group of laboratories building tools for planning resilient infrastructure investments in the mainland U.S. More recently, the infrastructure work in Puerto Rico earned the Argonne team a Secretary of Energy Honor Award.

Petri explained that Argonne's strengths in understanding and helping to refine the operations and development of the grid lie in applying mathematical methods for grid optimization and dynamics modeling. Once those are developed, Argonne researchers can translate them into useful tools, software and technologies that can ultimately be deployed by industry.

As America looks to move away from fossil fuels and work to lower the carbon dependence of its electricity generation, additional complexities will be introduced to the grid.

"It's not like one day we're going to be using fossil fuels and the next only renewables," Petri said. "There will definitely be a transition."

In a world in which the grid is supplied primarily by renewables with incorporated large-scale energy storage, it will have to be sensitive to the fact that there are certain times a day when the wind is not blowing or the sun is not shining, and manage the demand appropriately.

"Maybe we need more batteries to back up the grid in that case, and we will need to accommodate new devices at the edge of the grid," Petri said, "but no matter what, it's going to certainly be a historic change to the way you would expect the grid to operate."

Provided by Argonne National Laboratory