Hours or days may pass before power can be restored. 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. This is excerpted from an article by John G. Kappenman, the head of Transmission Power Engineering at Minnesota Power. Solar flares are related to sunspots on the sun and they go through a cycle about 11 years in length.
Solar wind is steady and relatively low speed.
At the peak of the 11-year cycle, flares and sunspots are numerous and the solar wind varies greatly in speed. When major flares and eruptions occur and the energized, fast moving stream encounters the earth, the earth s magnetic field is disturbed. Note that we are currently approaching a solar maximum. As the previous cycles suggest, relatively high solar activity is likely for the next 2 to 3 years. As the 1989 event showed, the enhanced solar wind near the solar maximum can wreak havoc on technological systems both in space and here on earth.