| by
Mitch Battros (ECTV)
Is this
what happened to 30 million people today? The Mayor of
New York hints of this possibility. Mayor Michael Bloomberg
of New York City made the following statement: Today's
events where "Probably a natural
occurrence which disrupted the power system up there," referring
to a power grid based in the Niagara Falls area.
Disturbances
caused by solar activity can disrupt these complex power
grids. When the Earth's magnetic field captures ionized
particles carried by the solar wind, geomagnetically
induced currents (GIC) can flow through the power system,
entering and exiting the many grounding points on a transmission
network. GICs are produced when shocks resulting from
sudden and severe magnetic storms subject portions of
the Earth's surface to fluctuations in the planet's normally
stable magnetic field.
These
fluctuations induce electric fields in the Earth that
create potential differences in voltage between grounding
points which causes GICs to flow through transformers,
power system lines, and grounding points. Only a few
amps are needed to disrupt transformer operation, but
over 100 amps have been measured in the grounding connections
of transformers in affected areas.
Anatomy
of a Blackout
Previous
storms associated with Solar Cycle 22 (the 11-year sunspot
cycle that began in 1986) have had an unprecedented impact
on electric power systems. The great geomagnetic storm
of March 13, 1989, plunged the entire Hydro Quebec system,
which serves more than 6 million customers, into a GIC-triggered
blackout. Most of Hydro Quebec's neighboring systems
in the United States came close to experiencing the same
sort of outage.
Less
severe geomagnetic storm events in September 1989, March
1991, and October 1991 also hampered utility operations.
GIC interactions with new technological devices such
as large electric power controllers affected voltage
regulation and caused undesired relay operations in the
system equipment.
In contrast
to today's more severe solar storm cycle, the preceding,
relatively quiet 30-year period led designers of electrical
systems to overlook the possible influences of GICs.
Conventional threats—such as high winds, ice loading,
or lightning—did not cause the Hydro Quebec collapse.
Rather, it was the consequence of a threat that had never
been considered on a system-wide scale across the continental
network.
Many
portions of the North American power grid are vulnerable
to geomagnetic storms. Much of the grid is located in
northern latitudes, near the north magnetic pole and
the auroral electrojet current and in regions of igneous
rock, a geological formation with high electrical resistivity
(see figure.) Systems in the upper latitudes of North
America are at increased risk because auroral activity
and its effects center on the magnetic poles, and the
Earth's magnetic north pole is tilted toward North America
The network
depends on remote generation sources linked by long transmission
lines to delivery points. The effects of GICs build cumulatively
over a large geographic scale, overwhelming the capability
of the system to regulate voltage and the protection
margins of equipment. The Hydro Quebec outage resulted
from the linked malfunction of more than 15 discrete
protective-system operations. From the initial event
to complete blackout, only one-and-a-half minutes elapsed—hardly
enough time to assess what was occurring, let alone intervene.
Extensive
blackouts are the nightmare of the power industry. Once
power is interrupted in large metropolitan areas, diversity
of electric use on the network is lost. When power is
restored, all thermostatically controlled electric loads
come back on simultaneously. This stress, added to the
higher demands of many devices such as motors and transformers,
can draw up to 600% of normal load during restoration
procedures.
Such
a blackout is also likely to cause transient voltage
stresses and permanent damage to network equipment such
as high-voltage breakers, transformers, and generation
plants, which makes them unavailable for restoring power.
Hours or days may pass before power can be restored.
Oak Ridge National Laboratory assessed the potential
impact of a widespread blackout in the northeastern United
States from a geomagnetic storm event slightly more severe
than the March 1989 blackout as a $3–6 billion loss in
gross domestic product. This figure does not account
for the potential disruption of critical services such
as transportation, fire protection, and public security.
Other assessments placed the 1989 and 1991 geomagnetic
storm effects in a category equivalent to Hurricane Hugo
and the San Francisco earthquake in their relative impact
on the reliability of the electric power grid.
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Mitch
Battros
Producer - Earth Changes TV
http://www.earthchangestv.com
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