“The industry only changes following a big crisis and we’re about due for another one.” That was a remark made at a recent meeting of utility industry experts. I believe it.
It took the 12 hour Northeast blackout of 1965, which knocked out power to 30 million customers, to get us seriously working on coordinated, interstate transmission standards. The result was the formation of the North American Reliability Council (NERC) in 1968. We can also thank the disaster for pushing the development of transmission SCADA and programmable relays. There have been other less spectacular area-wide transmission outages since then (particularly in the Northeast for some reason). These have also resulted in major (overdue) operating changes.
Waiting for disasters to occur in order to take action may save a few bucks, but sometimes the potential risk is so high you can’t afford to let happenstance happen. You don’t want to check for a possible retinal aneurism by continuing to lift weights at the gym!
When we discuss grid security we usually are thinking ‘cyber-security’. But the power system is far more vulnerable to other types of attacks, such as physical destruction of critical system components. These mostly go ignored. (see Cyber-threat or Cyber-hype?)
Then there’s the 800 pound-gorilla-sleeping-in-the-closet threat: a geomagnetic storm which, if big enough, could shut down the world’s power grids so destructively that they would be out for weeks, possibly months.
Our sun produces ‘solar winds’ of charged particles that can reach the earth. In turn, these streams of particles create magnetic fields that interfere with the earth’s magnetic fields. If the solar winds flare up large enough, the resulting magnetic fields can produce massive, low frequency currents in transmission networks. This, in turn, can easily destroy $10 million high voltage transformers which, in the case of widespread damage, would take weeks or months to replace.
The effects of these Geomagnetic Induced Currents (GIC) are similar to those of an Electromagnetic Pulse (EMP) generated by the detonation of a nuclear bomb. So it figures that there has been plenty of spending on research related to potential impacts of both GIC and EMP on the government and civilian power systems.
The findings? We could be in a heap of trouble if a large, or even moderate geomagnetic storm occurs.
Fortunately they don’t happen often. The last big one was in 1921, before anyone had miles of large scale transmission (the bigger the transmission ‘loop’ the bigger the effect). Then in 1989 we had another geomagnetic storm. This time 6 million customers in Quebec lost power for 9 hours. Not a world-scale calamity, but on the other hand, the 1989 storm has been estimated to be about one-tenth the strength of those that have hit the earth in the past. It was a much larger storm in 1859 that started scientists looking at the phenomenon in the first place. That’s frighteningly recent!
We are in the middle of a solar flare-up that started in January 2009 and is expected to peak in May 2013. Whether this is ‘the big one’ depends on the storm orientation, intensity and duration. Hopefully we’ll make it through okay. But who knows?
So what are we doing about the potential threat of GIC? Not much. I have to admit that I’ve always been skeptical of the potential for any real damage. It seemed to me like it’s just another of the ‘sky is falling’ alarms that go off every few years and then disappear. Now I’m not so sure we should go on ignoring it.
What can we do? Transmission operators already have sensors to monitor transformer currents for GIC effects but no one is seriously planning to make the system radically less vulnerable. There are ways to structurally design the high voltage system to minimize the magnetic interactions. Transformers can have built-in protection circuitry. But at present no utility or agency is going to retrofit or rebuild the grid infrastructure to protect against GIC, and therefore there’ll be no market for new GIC-safe transformer design until we have a crisis. A big part of the seeming complacency is that the biggest threat is to long-mileage interstate transmission where no one utility or other entity is fully responsible. NERC is the watchdog. But NERC is only recommending emergency response procedures and publishing GIC threat assessments.
This complacency could change as we consider looking at a bigger picture of ‘smart grid’. Or even ‘micro-grids’, because when it comes to GIC, smaller/local is better. As we move towards what some call Grid Optimization, why not consider making the system bulletproof against GIC?
For more reading on the topic, check out A Perfect Storm of Planetary Proportions in the March, 2012 issue of the IEEE Spectrum.