April 15, 2008

Reducing gridlock

Dr. Robert Peltier, PE, Editor-in-Chief

North America’s electricity grid has been described as the world’s most complex machine. The grid is unique among utility infrastructure systems for its need to have supply and demand—generation and load—balanced at all times. There still are no technologies for storing large quantities of electricity akin to liquefied natural gas tanks, voice mail, or e-mail servers. Because power consumption is instantaneous, dispatching generating capacity and switching feeders on and off are the only controls available to grid operators.

 

The spoils of power

Short power outages are a mere inconvenience for the average American household, which has been spoiled by highly reliable electric service. But reliability is essential for large factories’ profitability. To them, any outage—even one of just a few milliseconds—may cause a key manufacturing process to crash and shut down an entire assembly line.

Longer outages take bigger tolls. Here are some examples of the big business impact of a major power failure. Hewlett-Packard recently estimated that a 20-minute outage at one of its wafer fabrication plants would cause the loss of an entire day’s production, valued at $30 million. In California, a blackout in June 2000 cost Silicon Valley businesses $100 million, according to the Silicon Valley Manufacturers Group. According to the DOE, the great Northeast blackout of August 2003 cost the U.S. economy about $6 billion, including $4 billion in lost wages and profits. The joint U.S.-Canada task force assembled to determine why the blackout occurred put its cost at between $4 billion and $10 billion.

As the complexity of the grid grows, so do the costs of a grid disturbance and the ease with which one can propagate.

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