Threats to U.S. bulk power grid revive reliability concerns

By Peter Behr | 06/02/2016 07:05 AM EDT

The sharp historical demarcation between federal- and state-regulated portions of the U.S. power grid needs to be rethought as local utilities see more rooftop solar and battery storage technologies in their service areas, grid officials and experts said yesterday.

The sharp historical demarcation between federal- and state-regulated portions of the U.S. power grid needs to be rethought as local utilities see more rooftop solar and battery storage technologies in their service areas, grid officials and experts said yesterday.

Local utilities’ distributed resources, particularly customer-owned solar and storage facilities, may become large enough before long to pose potential threats to the interstate grid. Disruptions in cities or small towns — whether they’re accidental or intentional — could move upstream to the wider grid, said participants at a daylong grid security conference at the Federal Energy Regulatory Commission headquarters.

"There needs to be a lot of work done on distributed resources and how they are effectively integrated into the grid," said FERC Chairman Norman Bay.


"We do need to start thinking about the distribution system, the components that are being added to the distribution system, and especially some of the things on the customer side, as we take a holistic view of the system," said Patricia Hoffman, the Department of Energy’s assistant secretary for electricity delivery and reliability.

Reliability problems at the bulk power level are now showing up at the local distribution level, Hoffman said, noting the need to manage voltage and frequency fluctuations and ensure adequate supplies of reactive power, a critical component of local voltage stability.

"In essence, it is going to be very difficult for ISO [independent transmission system operators] and large utilities to figure out what is happening in some of these rooftop businesses or the batteries in some of these basements," said Mohammad Shahidehpour, an Illinois Institute of Technology professor.

At the same time, local microgrids that can be isolated to withstand massive storms or grid attacks can be vital resources to restoring power, as can customers’ energy resources if they can be managed for the grid’s benefit, other speakers said.

"We are taking proactive efforts to ensure these resources that can provide resilience — real resiliency to the distribution system — are well coordinated and able to be managed," said Mark Rothleder, vice president of market quality and renewable integration for the California Independent System Operator.

"We do not have to manage every rooftop solar resource, but when you have some type of controllability at an aggregate level, the coordination between the distribution system operator and the transmission system operator becomes ever more important," he added.

Chantal-Aimee Hendrzak, executive director of market evolutions for the PJM Interconnection, the grid operator in the Mid-Atlantic and eastern Great Lakes area, said "proliferation of distributed energy resources carries with it some reliability impacts."

She cited a voltage disturbance in Washington, D.C., on April 7, 2015, that caused power demands to be shifted automatically to customers’ backup generation units that were "behind the meter." Neither PJM nor Pepco, the local utility, could see what those units were doing at the very moment the two grid operators were trying to assess and stabilize the grid, she said.

Reliability impacts

Regulation of distribution utilities’ rates by state commissions began in 1887, in Massachusetts, and spread steadily from there, championed by Chicago electric power holding company executive Samuel Insull. Public and political outrage in the Great Depression over the failures of power holding companies — Insull’s and others’ — led to the strengthening of federal control over the interstate system but did not infringe on the states’ role, grid historians note.

Operators and regulators of the interstate grid have decades of experience running those networks, Hoffman said. "By comparison, in the distribution systems we are at the early stage of creating reliability standards, metrics and mechanisms" for sharing operational data about potential disruptions, she said.

Research on this issue is just beginning at the DOE national laboratories, as part of DOE’s Grid Modernization Lab Consortium project, she said.

"Dealing with the reliability aspects of these concerns will raise significant federal/state jurisdictional issues," she added in prepared remarks. But a better understanding of the technical issues must come first, Hoffman said.

The FERC grid security conference produced a paradox of conflicting assessments from officials and panelists. U.S. grid defenses are expanding in strength and sophistication; threat sharing and communication are improving; research is advancing; and the industry is building recovery capacity. But threats are also advancing, and new vulnerabilities emerge.

"The threat of cyber and physical attacks on the grid by nation-states, terrorist groups and criminal actors is at an all-time high; the challenge will continue to grow exponentially," said Marcus Sachs, senior vice president and chief security officer of the North American Electric Reliability Corp.

Paul Stockton, managing director of Sonecon LLC, an economic and security advisory company, and former assistant secretary of the Defense Department, said one threat that needs more focus is a simultaneous terrorist attack on the electric power and communications networks, which depend on one another. "Our adversaries may not do us a favor or kindness of attacking one sector" but may go after both to multiply the impact, he said.

Hoffman and other speakers noted the increasing dependence of the electric power sector on natural gas generation, and thus on the security of natural gas pipelines. DOE has a task for reviewing looking at natural gas issues, including safety conditions at 400 gas storage sites around the United States, following gas leaks that forced the shutdown of the Aliso Canyon gas storage facility in Southern California.

DOE is also working on pinpointing potential attack strategies that might be most threatening to the power network, said Devon Streit, deputy assistant DOE secretary for infrastructure, security and energy restoration.

Near the conference’s conclusion, FERC Commissioner Tony Clark asked members of the final panel for a single recommendation on a top security priority for the commission, noting the adage, "If you are protecting everything, you are protecting nothing."

"If you had a bumper sticker for, here is what the commission should focus on that has the biggest bang for the buck … what would it be?" he asked.

One panelist said it would be installing blocking devices to protect transformers against massive solar flares or electromagnetic pulses from a high-altitude nuclear attack. Another suggested giving grid operators better strategic government intelligence about potential attacks. A third said it would be focusing on workplace training on cyber risks. It became a long bumper sticker.