In 1991 near the peak of Solar Cycle 22, the SUNBURST monitoring system was installed to collect data on the characteristics and effects of geomagnetically induced currents (GIC) in electric power substations and generating plants across North America. This effort by Electric Research was sponsored by Electric Power Research Institute and many cooperating US and Canadian utilities. The immediate impact of GIC on power systems is to cause half cycle saturation of most of the power transformers through which the GIC flows.

SUNBURST data has shown that the harmonic currents and voltages which result from half cycle saturation can disrupt the power system operation, damage generators, and may accelerate transformer failures.

Prior to the initiation of the SUNBURST System, the prevalent power system concern was that GIC could, in extreme cases, fail power transformers. (During the March 1989 storm, a major bank of transformers at Salem Nuclear Plant were irreparably damaged.) SUNBURST data demonstrated that the even harmonics, 2nd and 4th of the power frequency, could induce circulating currents in the end ring of large turbine generators which are connected to the power system through GIC impacted transformers. During major events, these generator currents are predicted to be large enough to cause excessive heating. Many machines had no protection against this effect.

Capacitor banks which help maintain power system voltage may be tripped by the effects of the harmonic currents on the relay system which protect these units. This loss of capacitors, at the same time that the GIC impact on the transformers causes an increase in demand from the voltage support systems, may cause power system collapse if it were to occur at a system peak.

In 1999, SUNBURST-2000 was installed to provide real time data via the Internet. While the SUNBURST System has provided a wealth of data for research into the effects of GIC on power systems, all the data was only available after the solar event was over. A new array of smart sensors will send data directly to an Internet host which will process and display the information with less than a five second delay from the instant of occurrence at any of the worldwide sites.

Thus, Members of SUNBURST-2000 will have data displayed at their desk in time to act or react with full knowledge of the range and extent of the event underway. Also, working with NOAA and other researchers around the world who will have access to the SUNBURST-2000 data, we can quantify computer models to predict GIC events in advance of a storm.