Our electric grid

Posted on April 27, 2007


Look around you at all the things you use that need electricity to operate. Your lights, coffee maker, radio, television, and computer. Your cell phone may have a battery, but it’s useless if the cell tower’s battery dies too. If the weather’s really cold and the power goes out your furnace won’t turn on because the thermostat is electrical, and even if the thermostat has a battery backup, the blower is electric even if the furnace is gas or oil. So when the power goes out, pretty much everything we consider as a benefit of civilization comes to an abrupt halt.

Last week, a former contract employee for the organization responsible for controlling California’s power grid, the California Independent System Operator (Cal-ISO), got through security at around midnight and sabotaged the computers. Somehow the alleged saboteur got through a set of card scanners and a biometric handprint scanner and was able to access the high-security inner rooms where he activated the emergency shutdown (complete story). Had the sabotage occurred during a high-usage period like a summer afternoon, the outage could have caused significant problems with California’s electric grid. And for an idea of what I mean by “significant problems,” think problems similar to the 2003 North American Power Blackout.

Our electric grid is a mesh of high-voltage transmission lines that connect power plants located tens or hundreds of miles away from their customers, and the transmission lines are monitored by 1970’s-era technologies that cannot provide real-time information to the independent system operators. In the case of the 2003 North American Blackout, a single overloaded transmission line sagging into a tree set off the cascade of events that led to 50 million people in the United States and Canada being blacked out for hours or, in some cases, days. The entire might have been avoided (and it certainly could have been mitigated) if the Midwest Independent System Operator (MISO) had more accurate information regarding the conditions of their transmission lines.

Both of these incidents illustrate just how fragile and vulnerable our power grid is. The contractor’s employer had told Cal-ISO that the contractor’s access should be revoked, yet the contractor still got access to the emergency shutdown. Whether this was because of bureaucratic inefficiency, a failure of technology, or a problem with personnel training remains to be determined, but if a disgruntled employee can get access to the inner workings of Cal-ISO, then it’s reasonable to assume that some other sufficiently motivated person could do the same and drop a significant number of California’s 35 million people in to the dark. Similarly, if a sagging transmission line shorting out to a tree could instigate a black out affecting 50 million people, imagine for a moment what a group of terrorists with stolen dynamite could do to the grid.

One problem is that transmission lines can’t be monitored in real time. Transmission line data is always out of date, and so the independent system operators lack the accurate and current information they need to make smart decisions. And sometimes seconds could mean the difference between a blackout and normal operations of the grid. Technologies are being developed to alleviate this problem, but they will take years if not decades and billions of dollars to deploy, assuming that the state and federal governments of Canada and the United States mandate the upgrades.

A second problem is that the power grid simply isn’t robust enough. There aren’t enough transmission lines running in parallel to effectively handle the load in key parts of the country, and there aren’t enough regional transformers for one region of the country to supply power to another, so a break or shutdown in one part of the grid causes a cascade of problems throughout the rest of the grid. People understandably don’t want high-voltage transmission lines nearby their neighborhoods (NIMBY, anyone?), and because power transmission is a regulatory black hole, there isn’t a significant profit motive for the construction of more transmission lines. But without building more transmission lines, we can’t offload enough power from overloaded lines to prevent the very cascade that caused the North American Power Blackout of 2003.

And a third problem is that the power grid cannot be secured. The power grid itself consists of thousands of miles of high-voltage transmission line running through plains, mountains, deserts, and forests. It also consists of several key transformer stations that, if they go offline or are damaged, take entire regions down with them. It also consists of the power control stations, like Cal-ISO and MISO, whose security can no longer be taken for granted. At the moment, since the power grid is not sufficiently robust, the lack of security around the power grid is a major problem and puts the power grids of both Canada and the United States at serious risk of disruption.

The power grid we depend on for the benefits of civilization is presently both vulnerable and fragile. There are only a few ways to make is less so. The first thing we must do is build more transmission lines in order to take the load of the existing, often overloaded lines. Parallel lines reduce overall loading and provide the ISOs an alternative line to route electricity should one line go down for whatever natural or human-induced reason. Greater interconnection between regional power grids is also vital both to reduce the threat of a single transformer failure and to reduce the scope of a power outage. The ISOs responsible for controlling the flow of electricity need to have accurate information on the grid so that they can control the grid effectively (new technologies exist that can automate most of the ISO’s functions, but these technologies also need accurate and up-to-date data to be effective). And the ISOs need to be secure so that, in the event that their direct control is required, they’re on-line when they’re needed.

[Thanks to fellow S&R blogger Edmundo Rocha for pointing this one out.]

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