ECN Forum Forums General Topics of the Trade General Discussion Area Electrical Dependence?.

Scott35, I think you are referring to GICs, or geomagnetically induced currents related to solar-flare activity. That can be a real bad problem in power transmission, for they cause DC currents to circulate from one switchyard ground grid to another. High-voltage transformers are usually wye-grounded, and DC currents of <10 amperes can fry transformer windings in fairly short order. Because current transformers are AC devices, they cannot reflect DC to be sensed by protective relays that are used for a major part of transformer protection.

Solar-flare activity is supposed to peak on an 11-year cycle, so effort and money to invest in solving the problem varies. I haven’t read anything that related the NE 14-August outage to solar activity, although there have been well-documented cases of GICs being a problem at other times in the northeast. Apparently rock content in soil determines an area’s susceptibility to the problem.

A few extra-geekey links are http://ieeexplore.ieee.org/xpl/abs_free.jsp?arNumber=141760 http://wham.phys.ucalgary.ca/satellites/html/sp_weather.html http://www.estec.esa.nl/wmwww/WMA/spweather/workshops/spw_w4/proceedings/PulkkinenPoster.pdf

A couple of decent outage links:
http://www.spectrum.ieee.org/WEBONLY/special/aug03/black03.html
http://platts.com/features/poweroutage/index.shtml

Another not-too-geekey link is: http://www.itctransco.com/documents/B_8-14-2003_ITC_Analysis.pdf

On the electrical dependence:

Saturday I visited a 17th century palace, which had been kept intact. The owners kept it more or less like a museum already in the 19th century and it's now a real museum. It has only had some minor modifications since it was constructed. To this day, there is no central heating, no running water and no electricity. The only light is the daylight coming in through the windows. And the guide's torchlight.

What surprised me was that you really didn't miss the electric light. One could probably get by really well at night too with just an oil lamp.

But here comes the shocker: The lack of heating meant that it was far below freezing indoors during the winter. There's ice in the attic and top floor in winter. "Doesn't the cold damage all the paintings?", I asked the guide. "No, on the contrary. The paintings and wallpapers have been excellently preserved for 300 years because of the cold and the lack of light."

The palace was never completely finished. You can see the ongoing construction work in the largest room as the worker left it off 300 years ago. No cables and no water pipes there, just the beams