DOE probes need for an emergency stockpile of transformers to power the grid

By Peter Behr | 03/12/2015 08:29 AM EDT

The Energy Department has begun an inquiry into the vulnerability of large power transformers that are crucial to U.S. electricity delivery, officials confirm. The study could lead to a strategy for expanding a strategic stockpile of spare transformers to help the grid recover from major cyber or physical assaults or solar storms and other natural disasters.

The Energy Department has begun an inquiry into the vulnerability of large power transformers that are crucial to U.S. electricity delivery, officials confirm. The study could lead to a strategy for expanding a strategic stockpile of spare transformers to help the grid recover from major cyber or physical assaults or solar storms and other natural disasters.

The project, at DOE’s Office of Electricity Delivery and Energy Reliability (OE), addresses potentially existential threats to the interstate high-voltage transmission network that have been highlighted in government studies as far back as 1990, and increasingly since the Sept. 11, 2001, attacks.

The DOE study aims at key, still-unresolved questions that have held up a comprehensive federal response on the issue, according to officials.


"The question, as we frame it here, is what the risk is to transformers, and to the overall system, from a loss of transformers, and [what are] appropriate measures to mitigate that risk," said a DOE official, who spoke not for attribution.

The threat to the grid was highlighted by five senators who wrote in December 2014 to Energy Secretary Ernest Moniz, urging DOE to support a larger stockpile of large transformers.

"For well over two decades Congress and successive administrations have recognized this critical vulnerability," the senators said. The power industry has created programs to inventory spares and share them in emergencies, they added. "However fully addressing this issue will require coordination and transparency between utilities, regulators and equipment manufacturers," the senators’ letter said.

The letter was sent by Sen. Roy Blunt (R-Mo.). He was joined by Sens. Claire McCaskill (D-Mo.), Tim Kaine (D-Va.), Cory Booker (D-N.J.) and Johnny Isakson (R-Ga.).

Unresolved issues

The DOE official said that before creating a strategy for stockpiling transformers to bring back parts of the grid, the first step is to define the problem. "You realize you have more questions than answers. We don’t have a good sense for exactly what the scale of risk is," the official added. How many transformers would be damaged under various scenarios? How many would have to be replaced, and under what conditions? What would be the effects on the grid? the official said.

"If we can come to some resolution as to what is needed, that will give us what the solutions may be," the official said.

The Electric Power Research Institute has discussed the study with DOE, EPRI spokesman Clay Perry confirmed.

A confidential analysis by the Federal Energy Regulatory Commission in 2013 warned that an attack that took down as few as nine strategically vital transmission stations on a hot summer day could cause far-reaching cascading outages. If the stations’ transformers were wrecked, recovery could take months. But some DOE staff members privately called the scenario highly unlikely, according to a report by the Energy Department’s inspector general (EnergyWire, Feb. 5).

James Clapper, the director of national intelligence, testified to Congress last month that rather than a "Cyber Armageddon" that wipes out an entire U.S. infrastructure, "we foresee an ongoing series of low- to moderate-level cyberattacks from a variety of sources over time, which will impose cumulative costs on U.S. economic competitiveness and national security."

Another issue is the potential impact of a once-in-a-century solar storm, triggering damaging rogue currents traveling through the grid. In the worst case, several hundred transformers would be fatally damaged, NERC consultants concluded (ClimateWire, Oct. 10, 2012).

The North American Electric Reliability Corp. (NERC), the FERC-appointed grid security monitor, challenged that conclusion. The disruption would most likely cause an immediate but short-lived blackout, so that transformers would not be destroyed, NERC said. The question of the likely damage from a possible massive solar flare is still unresolved, the DOE official said.

Last fall, DOE funded a study of the potential spare transformer reserve for the Western Area Power Administration, a DOE office that markets and transmits electricity over a 17,000-mile transmission system in 15 central and Western states. "The results indicated we need to do a lot more work to understand what the needs for spare transformers are," the official said.

Large transformers are essential to the grid’s operation, boosting voltages to facilitate long-distance power delivery and then stepping voltages back down to connect to utility distribution networks.

But the United States depends heavily on foreign suppliers, contributing to the procurement lead times. A DOE study by ICF International in 2012 found that six U.S.-based transformer manufacturers filled 15 percent of the demand for new units in 2010, and the dependence on foreign sources is even greater for the very large transformers used in the high-voltage grid.

A comprehensive DOE analysis could identify gaps in what is, so far, a voluntary industry response to expand the transformer stockpile.

NERC has created a database of critical transformers at U.S. power companies, and the Edison Electric Institute operates a Spare Transformer Equipment Program (STEP) that requires participating utilities to sell spares to other participants that lose transmission substations to a terrorist attack (EnergyWire, March 28, 2014).

FERC has two standards — one on physical security of grid facilities and the other on the threat of a solar superstorm — that could result in increasing investments in spare transformers.

The physical security standard drafted by NERC requires transmission companies to identify their most critical substations, and that information will feed into an analysis of transformer deployment and requirements for spares, an industry official said.

The Electricity Sub-sector Coordinating Council, an industry/government partnership of which NERC is a partner, will pull together proposals for industry and government collaboration on expanding a transformer stockpile, officials said.

Industry responses

The prospect of expanded orders for large transformers has stirred an industry response.

An email copy of the senators’ letter to Moniz was titled "Final ABB DOE letter," suggesting the involvement of ABB, a leading transformer manufacturer with a production plant in Jefferson City, Mo. ABB did not reply yesterday to a query about the letter, nor did Blunt’s staff.

ABB has developed a mobile, rapid recovery transformer, "RecX," in partnership with the Department of Homeland Security, EPRI and CenterPoint Energy in Houston.

Delta Star, a U.S. transformer manufacturer, says it is drawing up plans for a large mobile unit that would deliver 345 kilovolts — a common size in the high voltage grid.

"We know we have some technology to do that," said Steve Newman, Delta Star vice president based at its Lynchburg, Va., production facility. "We have indicated to a number of customers we think we are prepared to do that."

Newman said the company’s transformers can be delivered on highways and be running inside of four to 10 hours, permitting a much faster recovery than would be possible if a conventional transformer had to be shifted from one substation to another, he said.

"We want to be a good partners with the government, and we have had numerous conversations with them," Newman said. "We think there is a pathway that could allow for mobile units to be staged throughout the country, including military bases.

"A good policymaking decision for Congress and others is understanding the risk and making a determination what they want to do on the budget."

Delta Star’s 230-kilovolt transformer costs under $2.2 million, Newman said. A 345-kV unit would be significantly more, making the analysis of the number of spares the nation requires a big budget question.

"The industry is able to recover costs on spare equipment and is able to work with regulators to build those [grid] resiliency costs into the business," an industry executive said. "But there also is a role for the federal government if we are looking at extraordinary national security issues and big, big scenarios. You get to a point where you outstrip the customers’ ability" to provide enough spares.

Thomas Siebel, chief executive of C3 Energy, a California-based smart grid analytics firm, told House Energy and Commerce Committee members last week that he is pessimistic about a comprehensive grid defense program ever getting through Congress, at least under ordinary circumstances.

"Before we really do something about this … we are going to have the equivalent of 9/11," he predicted. "There is going to be some disaster, and it’s not going to be good. Then we’ll get serious."

Reporter Blake Sobczak contributed.