July 2001

A Smarter Power Grid

New "power electronics" that swap voltage from line to line may be the best-and cheapest-fix for our aging electric grid.

By Peter Fairley

Thousands of megawatts of cheap, clean hydroelectricity from Canada are continuously rushing into the New York Power Authority's sprawling substation in Marcy, NY-enough juice to light up 40 World Trade Centers. For almost a half-century, the Marcy facility, located just a few miles from the remote Adirondack National Park in upstate New York, has transformed this torrent of electricity from a blistering 765,000 volts to the slightly more manageable 345,000 volts used by the overhead transmission cables that feed power-hungry Manhattan 300 kilometers to the southeast.

But the real action at Marcy these days takes place in a nondescript metal building, easily overlooked amidst the 40-meter-high towers supporting the mass of transmission cables. Here, European engineering giant Siemens has just installed the world's most sophisticated high-power switch. If things get really hot this summer, the ability of the specialized chips inside the device to route electricity exactly where it's needed just might save New York City's cool.

The novel Siemens switch that holds these electric-power processors stands four meters high, and its silicon valves juggle electrons at power levels that would blow your cell phone or PC to bits. But just as silicon chips in your cell phone process electromagnetic signals to transmit information, Siemens's brawny electrical-power processor can filter and manipulate the alternating current flowing through the Marcy station. The immediate goal is to stabilize central New York's stressed electric grid, making it safe to transmit more energy through the lines. Then next summer, with a few more patch cables and a hefty new fuse added to the system, the power switch should be ready for an even more sophisticated trick: nimbly swapping electricity between high-power transmission cables-a feat never before attempted.

If it succeeds, the electricity swap will be like a coronary bypass for a critical artery in the increasingly sclerotic national power grid. In many ways, the energy "crisis" that is gripping California and threatening the rest of North America is as much about getting electricity to flow where you need it-when you need it-as it is about a lack of energy. The problem is that the existing network of high-power transmission lines, the interconnected web of electricity that keeps the continent charged (power grids in northern Mexico and in Canada are closely intertwined with those in the United States), was built in the middle of the last century and was never meant to handle the complexity and congestion of today's ever growing energy demands and changing markets.

In light of this situation, the North American Electric Reliability Council, the industry's voluntary watchdog group, is telling just about anyone who will listen that the system is at risk. "The question is not whether, but when, the next major failure of the grid will occur," wrote the group's general counsel David Cook in a recent entreaty to the U.S. Department of Energy in Washington, DC.