Power Pools & Reliability
SUMMER IN WISCONSIN. Responding to concerns about the electric shortages of the summer of 1997 and fears that they could happen again, Wisconsin PSC...
unprecedented strains on the system.
During the worst of the heat, however, power flowed where it was needed most, although sometimes at a very high cost in order to overcome transmission congestion and competing demands from buyers. Record prices for baseload and peak power were recorded on France's Powernext Exchange, the Amsterdam Power Exchange, and in Germany's domestic markets, while the export price of energy flowing from England into France also hit record highs.
With fresh memories of the massive North American power failure of Aug. 14, 2003, some European power managers downplayed the possibility that a similar event could strike the Continent. But they were soon proven wrong by three separate outages-though they were unrelated to the heat storms.
The first event affected London on Aug. 28, when a failure on a 275-kV distribution circuit stranded evening commuters and cut power to a quarter of a million people for periods ranging from 30 minutes to several hours.
Less than a month later, power outages struck Denmark and southern Sweden, depriving nearly 4 million residents of electricity for an afternoon. Then, early in the morning of Sept. 28, Italy experienced its worst blackout in history, when a transmission failure in Switzerland cascaded across the Alps, blacking out local systems all the way to Sicily. In all, some 50 million Italians experienced "Black Sunday."
These system failures derived from what might be considered classic outage causes, says David Porter, head of the United Kingdom's Association of Energy Producers. "The problems we had in the U.K. could have arisen just about anywhere at any time," Porter says. "The famous power cut we had here in parts of London was the result of somebody fitting the wrong relay, in effect putting the wrong rate fuse into the system. It was a human error."
The triggering event of the Italian outage was a power line sagging into a tree, although failures in communication made the event far worse. At the time, Italian utility operators were in the process of refilling pumped-storage hydro reservoirs, using approximately 2,500 MW of energy. Had Swiss grid controllers gotten the word out to the Italians to cease the pumping operations, much of the damage might have been contained.
"This does suggest that countries need to look at security of supply in terms of the physical assets and re-evaluate whether systems are strong enough," Porter suggests.
That is exactly how the European Commission has responded-even though a formal memo on the Italian blackout stated, "This incident is independent from the creation of the EU internal market." Re-evaluating the TEN-E list of transmission and distribution priorities, energy officials have proposed expediting development of several projects into the 2005-07 period. Top on the list, of course, was the Italian/Swiss border interchange, along with improved links between the Continent and Scandinavia and Russia, between France and Belgium, and modernizing the Haru-Espoo high-voltage network to improve connections among countries on the Baltic Sea. Also proposed for development by 2008 are upgrades between Spain and Portugal, and a fourth undersea cable connection from Demark and Norway.