Research Summary provides results from solar storm activity.
Press Release Summary:
EPRI measures geo-magnetically induced currents through its SUNBURST program, a system of strategically positioned monitoring sites throughout U.S. and Canada. It uses data from that system, to provide guidance to utilities on keeping power delivery system functioning during solar storms. According to EPRI, nation's grid system was largely unaffected as 2-day solar storm pummeled Earth starting March 8 with massive blast of plasma that was ejected from the sun at as much as 4 million mph.
Original Press Release:
EPRI Research Summary - Results from Solar Storm Activity
The nation's grid system was largely unaffected as a huge, 2-day solar storm pummeled Earth starting March 8 with a massive blast of plasma that was ejected from the sun at as much as 4 million miles per hour. At its peak the flare activity was the most intense solar event since 2006. No power disruptions were reported from the storm that rapidly dissipated on March 9.
While the research team continues to see activity, it made sense to provide the highlights of this event thus far.
The Electric Power Research Institute (EPRI) measures geo-magnetically induced currents (GIC) through its SUNBURST program, a system of strategically positioned monitoring sites throughout the United States and Canada. It uses data from that system, to provide guidance to utilities on keeping the power delivery system functioning during solar storms and to provide feedback to those developing GIC models and forecasting tools. In the future, models of the power system, designed to evaluate the flow of GIC could be included to enhance the capability of the system.
SUNBURST GIC Activity Summary, March 7-9, 2012
The SUNBURST monitoring system recorded several periods of minor and moderate level GIC between the early morning hours of March 7, 2012 and mid-day on March 9, 2012. This GIC activity was the result of several solar flares from the same active sunspot region on the sun, and it can be broken down into three separate periods of activity with relative calm between.
It should be noted that the GICs recorded during these periods of activity are still quite small relative to the larger storms recorded during the previous solar cycle. During that cycle, SUNBURST recorded several severe events with multiple sites experiencing GICs in excess of 100A.
March 7, 2012
The start of GIC activity coincided with the arrival of a CME at 04:27 UT. For low-level events, the sudden impulse - which signals the start of activity - sometimes produces the largest GICs during an event. This was not the case for this event. The maximum GICs occurred several hours later. This activity lasted for approximately 12 hours.
For this first period of activity, only the Grand Rapids site in Manitoba experienced neutral dc currents in excess of 10A. The peak GIC recorded at this site was 21.9 A, which was also the largest GIC recorded over the entire 3 day period.
The following table lists the neutral current levels by site for March 7, 2012. Only sites that experienced significant GIC levels are included.
Central Hudson - Pleasant Valley: -7.0A to 7.4A
Central Hudson - Hurley Ave.: -9.1 to 6.3A
CMP/BHE - Chester: -4.1A to 6.0A
Manitoba Hydro - Grand Rapids: -21.9A to 9.6A
Con Edison of NY - Goethals: -6.1A to 7.3A
TVA - Paradise: -6.4 to 6.3A
In addition, Jim Kleitsch at ATC reported that one of their sites experienced neutral dc currents in excess of 10A.
March 8, 2012
GIC activity picked up again on March 8th at approximately 11:00 UT with another sudden impulse. NOAA's Space Weather Prediction Center indicated that this sudden impulse was nearly three times as large as the one that occurred a day earlier. In this case, the largest GIC recorded during this period of activity occurred at the time of the sudden onset. However, lower level GICs continued to be recorded for approximately 12 hours.
For this period of activity, two sites experienced GICs great than 10A. The largest was Tennessee Valley Authority's Paradise site which recorded -13.8A of neutral dc current at approximately 11:07 UT.
The following table lists the neutral current levels by site for March 8, 2012. Only sites that experienced significant GIC levels are included.
Central Hudson - Pleasant Valley: -8.2A to 8.8A
Central Hudson - Hurley Ave.: -11.0 to 7.0A
Manitoba Hydro - Grand Rapids: -6.2A to 4.9A
Con Edison of NY - Goethals: -7.3A to 7.4A
TVA - Paradise: -13.8 to 12.8A
March 9, 2012
After another short period of relative quiet, GIC activity again picked up during the very early hours (UT) on March 9th. In this case, there was not another sudden impulse event, so this activity was most likely caused by the more recent coronal mass ejection (CME), or the combined effect of the two CMEs in relatively close succession. Activity started at approximately 02:00 UT with the largest GICs occurring between 06:00 UT and 11:00 UT.
Of the three days of activity, this was the only period during which a "GIC Event" occurred as defined by SUNBURST. This requires at least two sites to experience neutral dc currents over 10A for at least 15 seconds simultaneously. This happened several times during the period mentioned above.
During this event, six SUNBURST monitoring sites experienced GICs over 10A with the largest GICs recorded at the Grand Rapids site in Manitoba. That site experienced neutral dc currents of 20.5A. In addition, Jim Kleitsch has reported that at least two of the ATC GIC monitors recorded neutral dc currents in excess of 10A with the one site recording approximately 25A.
The following table lists the neutral current levels by site for March 9, 2012. Only sites that experienced significant GIC levels are included.
Manitoba Hydro - Grand Rapids: -20.5A to 19.2A
TVA - Paradise: -18.0 to 8.2A
Central Hudson - Pleasant Valley: -13.2A to 13.0A
Central Hudson - Hurley Ave.: -16.3 to 18.9A
Con Edison of NY - Goethals: -11.6A to 14.1A
Con Edison of NY - Sprainbrook: -2.8A to 3.0A
ATC - North Appleton: -1.7A to 3.0A
CMP/BHE - Chester: -7.5A to 13.6A
NGrid US - Kent County: -2.5A to 2.1A
NGrid US - New Scotland: -2.7A to 3.9A
EPRI Research
EPRI is working with NERC and the utility industry to develop, among other things, the capability for utilities to assess the impact of an extreme GMD event on the grid. A few highlights of this research with regards to system planning studies are:
EPRI is also pursuing research in the following areas to assess and reduce the risk of geomagnetic disturbances:
Improved storm warning to increase forecasting accuracy and lead times. This effort involves collaboration among experts, with EPRI SUNBURST data providing key inputs into improved forecasting models. EPRI also is working with the North American Electric Reliability Corporation (NERC) on a project to develop a continental model that will help clarify likely impacts on the grid.
Increased real-time system awareness to support informed utility operations during storm conditions. EPRI is exploring three research areas to increase such awareness. The first is research assessing the use of existing microprocessor-based relays to estimate GIC and transformer response by directly measuring harmonics and voltage in real time. The second is research to explore the use of EPRI's existing network of power quality monitors to examine harmonic generation in transformers during solar storms. The third is research on meaningful signal analysis of these data streams to allow an accurate assessment of the risk to a specific transformer and the risk to the grid as a whole. In addition, the data will serve as valuable input into future storm forecasting and assist with forensics of failed equipment.
Increased utility collaboration. EPRI has established an interest group to shape the research portfolio, better understand geomagnetic disturbances and other high-impact low-frequency (HILF) events; and share and document current industry best practices.
Key technical contacts on the subject at EPRI are:
Rich Lordan, P.E. 650-855-2435 rilordan@epri.com
Randy Horton, Ph.D., P.E. 205-424-3927 rhorton@epri.com
About EPRI
The Electric Power Research Institute, Inc. (EPRI, www.epri.com) conducts research and development relating to the generation, delivery and use of electricity for the benefit of the public. An independent, nonprofit organization, EPRI brings together experts from academia and industry as well as its own scientists and engineers to help address challenges in electricity generation, delivery and use, including health, safety and the environment. EPRI's members represent more than 90 percent of the electricity generated and delivered in the United States, and international participation extends to 40 countries. EPRI's principal offices and laboratories are located in Palo Alto, Calif.; Charlotte, N.C.; Knoxville, Tenn.; and Lenox, Mass.
Contact:
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dkintner@epri.com
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