GRID:

Solar storm triggers slow-moving earthbound tempest at FERC

First of two articles.

Correction appended.

Just after 2:44 on the morning of March 13, 1989, rogue electrical currents caused a large voltage regulation unit to shut down on the Hydro-Québec power system 300 miles north of Montreal. Other controls automatically tripped off to protect the network.

Within one minute, the massive La Grande Hydroelectric Complex east of Hudson's Bay was cut off from Quebec cities to the south, triggering a cascading blackout that temporarily cut power to nearly 6 million people in the province.

The currents came from a powerful solar eruption that has made the incident the center of a debate before the Federal Energy Regulatory Commission over the potential damage a solar superstorm might do to the U.S. electric power grid.

In essence, the sun sent an electromagnetic cloud coursing to the Earth, where transmission lines acted like antennae, picking up the current and sending an overload through Quebec's grid. Because the system shut itself down automatically, no major grid components were damaged and power was restored in about nine hours.

But the event continues to create heat at FERC, which has started a controversial rulemaking on the subject. It's timely because a new cycle of heavy solar flare activity is under way, but there is no resolution on the horizon. There is also no scientific consensus on the degree of risk to expect, but the Department of Energy's Pacific Northwest National Laboratory gave this ominous warning in a 2011 report: "Without doubt, a major geomagnetic storm will again hit Earth. It is not a matter of if, but when."

The issue comes at a time when climate policies by states and the Obama administration are putting additional burdens on the nation's three aging electricity grids. Thirty states have passed renewable portfolio standards that require rising percentages of electricity to come from solar and wind power, forcing grid managers to deal with more on-and-off power supplies. Meanwhile, President Obama's push to build more electric cars will create more power demands.

It also dovetails with another climate-related problem. A first line of defense against solar storms involves quickly dividing the grid into smaller, survivable segments to limit widespread damage to vital equipment. Such "islanding" strategies are also related to proposals to reduce greenhouse gases by relying on more energy-efficient distributed power generation for future grid renovations.

How fast the industry can move on these issues remains a question. The industry's reliability monitor says it is accelerating research, but the full extent of the solar threat and its solutions may take several years of monitoring and equipment testing, according to the North American Electric Reliability Corp. (NERC) in its filing with FERC.

A standoff over potential damage

James Fama, vice president for energy delivery at the Edison Electric Institute, representing investor-owned power companies, said the solutions may come more quickly. "Individual companies and grid operators are already working on the issue," he explained, "so this is not going to go on and on."

But the industry is pushing back against fixed timetables for action and insisting that the industry's consensus-based process for setting reliability standards be allowed to play out.

FERC has sided with consultants' warnings that currents from a massive solar electromagnetic pulse -- if not blocked -- could overheat and possibly destroy a large number of vital transformers that currently lack replacements, leaving affected cities without power for months.

The U.S. power industry and NERC argue in filings with FERC that the Quebec incident shows the currents would touch off disruptive power flows that would take the grid down automatically, before transformers were damaged. There would be temporary blackouts, but equipment would remain unscathed, according to Richard Lordan, senior technical expert at the industry's Electric Power Research Institute (EPRI).

FERC has not accepted that view. The commission proposed in October a two-step defense that would first require U.S. transmission line and generation owners to prepare emergency operating plans to defend the grid against solar geomagnetically induced currents, known to the experts as "GICs."

Under the proposed rule, the emergency plans would be followed by a second mandate requiring companies to protect vital equipment -- and prevent a cascading grid blackout. That second mandate could compel power companies to purchase blocking devices to protect many hundreds of transformers, some costing $1 million or more apiece, industry officials say.

Can there be a safe shutdown?

Four major U.S. industry groups are fighting both FERC initiatives. The Edison Electric Institute, American Public Power Association, Large Public Power Council and National Rural Electric Cooperative Association argue that FERC lacks the scientific certainty and technical consensus to act.

Instead, they urge the commission to support continued research to define the threat, being conducted by an industry task force led by NERC.

All the rest of FERC's proposed plan would be postponed for several years of research followed by attempts to form an industrywide consensus on new defensive measures before any plan would go to FERC for approval.

John Kappenman, an expert on solar storms who runs a consulting firm based in Duluth, Minn., contends there isn't clear evidence that the grid could protect itself from a record solar storm by automatically shutting itself down, as NERC predicts.

"We have no agreed-upon test protocols, test facilities or even numerical simulation models to certify in any way that transformers or other power grid equipment or systems will be safe to high levels of GIC," Kappenman said. He is co-author of a report by Oak Ridge National Laboratory warning that several hundred big transformers could be knocked out by a massive storm. FERC's proposed rulemaking is based on that analysis.

"Where is the data? Where are the models? Where did this rosy conclusion come from?" he asked in comments to FERC. There is no legal or technical basis to rely on EPRI's safe shutdown scenario, Kappenman contends.

Which scenario is more likely? Industry officials say the Quebec event proves minimal harm. But some experts aren't certain. "I'm not aware of any studies, tools or models that would do that analysis and give an answer to that question," said Diwakar Tewari, senior consultant for power delivery for SAIC Inc. in Sacramento, Calif.

Large unknowns linger

NERC, working with EPRI and industry experts, says it must study the complex interactions of solar currents on different types of transformers at different North American latitudes. "We need models that describe how the transformers heat up during a storm. There aren't very many of them," said Luis Marti, manager of special studies at Hydro One, which delivers power to Ontario province.

The 1989 solar storm did knock out one transformer, an older model being used at a nuclear power plant in Salem, N.J. Kappenman said this illustrates transformers' vulnerabilities.

The extent of that threat to the older transformers has not yet been documented, however.

"I do not know how many of those transformers are out there today. I know it is a limited number," EPRI's Lordan said. "They are more vulnerable to quicker heating than the other transformer."

He added, "When we talk with the transformer manufacturers, they say a handful may be out there." It's not the kind of numbers Kappenman cites, he said.

"There are two principal things we need to know," Lordan said. "Ultimately, from a highest level, is the system vulnerable, and what is a reasonable, cost-effective mitigation strategy?" There are 2,000 big transformers that may be at risk, with many different designs.

"The questions we're still trying to figure out is exactly how all these different transformers respond to a geomagnetic disturbance," he added. There isn't time or money to test them all, so EPRI hopes to isolate six or eight major classes of transformers and test their resistance to the low-voltage GICs.

Kappenman accuses EPRI of sitting on years of data measuring the effects of smaller GICs.

Lordan counters that EPRI has been measuring GICs since 1990, drawing on data from monitors at different places on the grid. It assists researchers who need specific information about parts of the grid they are studying.

"There are certain things we can't do," Lordan explained. EPRI is prohibited by homeland security regulations from providing that grid data in order to protect the grid against sabotage, he said.

An 'imperfect' set of defenses

The potential threat of solar storms has been on Washington's agenda for a decade, since a congressional commission was formed to investigate the issue. And the Quebec blackout was a quarter-century ago. EPRI has a long-running "Sunburst" research program.

"Very few of these tests have been done, unfortunately, to date," explained Mark McGranaghan, EPRI vice president of power delivery and utilization. "So we're living with limited information even after all these years of doing research on [geomagnetic disturbances]. That's why it's such a critical thing right now. "

Testing the eight or 10 transformer types costs $100,000 to $150,000 per test, Lordan said. "It's not inexpensive, but it's manageable.

"The original plan that we had on the project did not include testing of transformers," he said of EPRI's solar storm research project. Now that is a priority, but EPRI needs more money from industry to do the work. "We have sufficient funding in the project now to do two transformer tests. We need funding for half a dozen more," he added.

If the first part of FERC's proposed rule is made final, NERC will be given two months to issue a new reliability standard requiring grid operators and owners to prepare emergency plans to protect against solar storms.

Industry officials say grid operators can "effectively manage" the risk as the research agenda is completed, by using advance warning of solar storms via satellites to put planned operating defenses in place, isolating vulnerable transformers, bringing more generators online or even deliberately blacking out cities to protect key components.

"Operational procedures continue to be the only effective solution even though they remain imperfect due to the state of the art of supporting technologies," the trade groups said.

Correction: An earlier version misidentified Hydro One's role. It delivers power to Ontario.