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Solar Impacts Other Infrastructures
I would like to offer some comments on the July/August 2013 article “Geomagnetic Disturbances” .
While the article clearly identifies its scope as being the “impact on the power grid,” there are significant impacts on other forms of infrastructure that are in need of recognition.
Although not specifically mentioned in the article, goemagnetic induced currents (GICs) are primarily induced in the Earth’s surface and waters, and from this point they enter and the low resistance transmission systems (through transformer neutrals, as shown in Figure 1 of the article) to complete the GIC loops. However, any buried conductors, such as oil, gas, and water pipelines, offering a lower resistance path than the Earth’s surface may be similarly utilized by the GICs. Not unlike the power grid, these buried conductors (oil, gas, and water pipelines) are also susceptible to damage because of the flow of high magnitude GIC currents through them, albeit for different reasons.
All these factors present an underlying concern for facilities in addition to the power grid, such as power plants, refineries, and oil and gas pumping stations. Of particular concern are nuclear plants, which are primarily dependent on power from the grid to shut down and maintain the functioning of structures, systems, and components important to safety. Additionally, there are other nuclear power plant safety systems that may become damaged from solar activity that include onsite power supply systems, buried or surface piping and storage tanks, cooling towers, security systems, communication systems, and GPS-linked controls and communications. Systems totally contained within buildings, and with no links to the outside, may prove to be less vulnerable to GICs.
There is a definite concern for these facilities, in addition to the power grid, to recognize solar activity as an adverse natural phenomenon that may require both contingency planning and government regulations directed at mitigating the consequences to the extent practical, especially since solar activity of the intensity predicted by NASA and NOAA has not been experienced for the past 50 years, so we lack both the knowledge and experience of possible consequences.
 IEEE Power & Energy Society Technical Council Task Force on Geomagnetic Disturbances, “Geomagnetic disturbances,” IEEE Power Energy Mag., vol. 11, no. 4, pp. 71–78, July/Aug. 2013.
New Information for “History”
My “History” article, “An AC Pioneer: United Electric Light & Power Company,” published in the March/April 2013 issue of IEEE Power & Energy Magazine  requires five corrections, primarily due to new information recently coming to light. These corrections are as follows:
- Page 86, right column, line 12 of the second full paragraph: This line should read: “…A pair of 7,500-kW, 60-Hz, two-phase…”
- Page 86, right column, last sentence of the second full paragraph: This sentence should be deleted and replaced with: “After the closure of the East 29th Street power station, the frequency and phase-changing motor-alternator sets were relocated to United’s Elizabeth Street and 146th Street transformer substations and supplied by Edison 25-Hz feeders.”
- Page 88, caption for Figure 1: The correct address of the subject substation was 354 West 45th Street.
- Page 88, left and center columns, second and third sentences under the heading Distribution Issues: These two sentences should be deleted and replaced with: “United had installed 7,500-V transmission to the Elizabeth Street and 146th Street substations by 1906, while the power supplied to distribution transformers had been increased to 3,000 V by that time.”
- Page 96, right column, second and third sentences in the first full paragraph: These two sentences should be deleted and replaced with: “United adopted 3,000-V for the lines to distribution centers early in the 1900s, certainly by 1907, which supplanted the 2,300-V system.”
 J. J. Cunningham, “An AC pioneer: United Electric Light & Power Company,” IEEE Power Energy Mag., vol. 11, no. 3, pp. 84–98, May/June 2013.
–Joseph J. Cunningham