Trouble In the Sky!
Solar Activity May Cause Problems for Utilities
Many scientists indicate that we have entered the peak period for solar flares and
solar storms. During this period, from January through April 2000, these storms could
result in disruptions of satellite communications and less reliable electric power. Other
researchers predict potentially serious activity will extend through 2001 and the early
years of the new decade.
National Oceanic and Atmospheric Administration,
U.S. Department of Commerce

What does this mean? Large, expensive utility transformers could be permanently damaged
by GICs (Geomagnetic Induced Currents). For utilities, any power interruptions due to
solar storms would put pressure on the remaining grid. But utilities and owners of large
transformers have more sophisticated advance warning tools than ever before to help them
prepare and prevent loss.
What are GICs?
The geomagnetic effects from solar flares occur when the flare accelerates waves of
material and radiation energy toward the earth. This solar wind package can impact the
earths magnetic field and cause a period of fluctuations. These fluctuations can
induce the electric currents within conductive material on or near the earths
surface, including long utility transmission lines. These events are collectively known as
geomagnetic disturbances.
Industry sources report that transformers are failing at an above-average rate in areas
of the Unites States especially prone to geomagnetic disturbances the Northeast,
particularly the New England states down through the Chesapeake Bay area.
Why are GICs a Concern?
The GIC process is complex and covered in greater detail in the full-text article, but
the bottom line for utilities is that GICs can end up on utility transmission lines. When
transmission transformers are exposed to a GIC component, they are likely to overheat,
even if the low frequency portion is only a small, almost insignificant portion of normal
line current.
This can damage utility-owned electrical equipment and cause widespread power blackouts
like those that occurred in the 1980s in the Unites States and Canada. In March 1989, for
example, 6 million people were left in the dark by a blackout in the Hydro Quebec system.
What would happen if a slightly more severe event than the March 1989 storm caused a
widespread blackout in the Northeast? U.S. officials estimate the potential economic
damage at $3 billion to $6 billion.
Loss Prevention Is Key
The Space Environment Center (SEC) (www.sel.noaa.gov/index.html)
continuously monitors solar-geophysical activity. Alerts, warnings, and forecasts
concerning the state of the space environment, daily predictions and data summaries are
available from the SEC in real time on a variety of communication networks. The SEC also
issues 27-day and long-range forecasts, and similar warning programs and databases are
updated continuously around the world.
Utilities can takes steps to protect against GICs. Capacitor and compensator protection
circuits can be adjusted to make operation more reliable during magnetic storm activity.
Utilities also can monitor transformer neutral current to initiate a critical alarm so the
transformer can be removed from service to prevent overheating and possible catastrophic
failure. Loss prevention action must be fast to avert any physical damage.