Location: New York
Author: Ken Silverstein
Date: Tuesday, June 22, 2010
They sound like something from outer space. Well, actually they are. Geomagnetic disturbances can destroy satellites and power grids.
Scientists have the tools to provide some notice when the geomagnetic storms are ready to hit Earth. But the utility industry thinks it can do a better job of preparing for solar weather. To do so, though, requires collaboration between public and private entities -- a process that establishes a risk management paradigm and a cost allocation technique. While the odds of those storms hitting are small, they could cost billions to fix.
"Geomagnetic disturbances, the earthly effects of solar weather, are not a new threat to the electric sector," says a report written by the North American Electric Reliability Corporation and the U.S. Department of Energy. But recent analyses suggest "that the potential extremes of geomagnetic threat environment may be much greater than previously anticipated."
Those experts are citing Metatech Corporation and Storm Analysis Consultants, who are saying that if geomagnetic storms hit the transmission system they could result in widespread tripping of the lines and irreversible physical damage to large transformers. As such, NERC and the Energy Department have set out to prepare in advance for such events and to make recommendations for the industry to follow.
It's not theoretical. Perhaps the most damaging event to date has been the 1989 geomagnetic storm that caused a blackout in Hydro Quebec's systems. The same storm affected several electric utilities across Canada and the U.S., causing tripped transmission lines as well as a blown transformer. If the power grid were to get tripped at one of its interconnections it could cause a series of cascading events along the system.
In 2000 alone, solar storms occurred in April, June and July, with each lasting about four days. During that time, the storms tripped out some filter banks, static VAR compensators, as well as caused some voltage sags in the New York area and a large transformer to be taken out of service in the Pacific Northwest. While relatively benign, it has all affected the equipment running the power system.
Mitigating steps have been taken. But more are needed: The bulk power system is comprised of more than 200,000 miles of high-voltage transmission lines, thousands of generating plants and millions of digital controls -- all operated by at least 1,800 entities.
Among the general ideas espoused by NERC and the Energy Department is the conducting of an assessment of the North American bulk power system to identify areas where upgrades and modifications are most urgently needed. And, having the industry point out the places where extraordinary costs may be incurred before discussing out how such expenditures would be paid -- or whether it is worth it.
Monetary Damages
About every 11 years, the sun enters into what is known as a "solar maximum" when the sun expels bursts of material called "coronal mass ejections." That risk is now present and will be until 2011. The most susceptible regions are Canada, the Northern U.S. and Scandinavia, although the southern U.S. and coastal regions are also vulnerable.
The disturbances released by coronal mass ejections typically take 36 to 48 hours to reach earth -- enough warning to make preparations. Furthermore, the SOHO Spacecraft provides real-time observations of the solar wind, which gives NOAA's forecasters the ability to detect imminent geomagnetic storms and to issue more accurate short-term warnings to utilities, between 20 minutes and 50 minutes.
"The interconnected and interdependent nature of the bulk power system requires that risk management actions be consistently and systematically applied across the entire system to be effective," says the report. "A successful risk management approach will begin by identifying the threat environment and protection goals for the system, balancing expected outcomes against the costs associated with proposed mitigations."
The electric equipment in today's power systems are designed to operate on alternating current (AC). Solar storms introduce "direct current," or DC, into the power system. That can cause transformers to saturate, which degrades their performance and produces other undesirable effects such as equipment heating.
While the risks are difficult to quantify, the monetary damages that could result are much easier to analyze. According to the Oak Ridge National Laboratory in Oak Ridge, Tenn., a single large geomagnetic storm disturbance in the Northeastern U.S. has the potential to cause at least $3 billion to $6 billion in lost production if a transmission grid collapses. Every dollar of lost electric sales costs about $100 in foregone economic output.
What can electric utilities do? They must first use computer-generated models to simulate the effects that increased harmful currents would have on their systems. By studying those results, utilities can understand the nuances of their grids and feel more assured about the strategies they will implement.
They must also depend on their engineers to measure the harmful currents on their own transmission lines. If they are present, danger may be lurking. At certain levels, the damage may be irreversible. Otherwise, precautionary measures can be taken, says Palo Alto, California-based Electric Power Research Institute. For starters, transmission operators can reduce power flow through critical transformers, cut the distances that transmissions are flowing and reset protective relays so that they are less sensitive.
Utilities are well-rehearsed when it comes to fighting ice storms and hurricanes. But they still have plenty to do when it comes to defending against solar-related weather, which is why industry leaders are rallying their troops in advance of any crisis.
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