Board-Ansicht
Mix-Ansicht- Es geht wieder los: Energiekrise in den USA (und im Osten wird das Wasser knapp) - XERXES, 22.04.2002, 08:57
Es geht wieder los: Energiekrise in den USA (und im Osten wird das Wasser knapp)
SILICON VALLEY power substations and transmission lines have the capacity to handle up to about 2,300 megawatts at one time, just slightly more than the 2,100 megawatts used locally in peak times during the heady days of 2000. And Silicon Valley is expected to exceed that 2,300-megawatt threshold within the next couple of years as the economy improves and business electricity demand increases, says Justin Bradley, energy director for the Silicon Valley Manufacturing Group.
“If a critical component had been lost during a period of high demand, other equipment serving Silicon Valley would have experienced high overloads,” Mr. Bradley says of the state’s power transmission infrastructure. “Even at the lower demands seen [in 2001], a critical equipment outage could have caused problems.”
Silicon Valley has been described as the “most energy deficient area in the state” by the California Energy Commission. Only 15 percent, or 300 megawatts, of ongoing local demand is produced in the area, which means the rest must be imported from as far away as Washington state and Arizona. The Energy Commission recommends that Silicon Valley produce 40 percent of its peak total power, or 1,000 megawatts, to ensure a steady supply, including a steady voltage support, reliability and power quality.
Most of the imported electricity funnels through two major substations, the Metcalf substation in South San Jose and the Newark substation in Fremont.
A substation acts as a conductor and a converter of electricity. After electricity is generated at a power plant, it is transported at 230 kilovolts via wires from substation to substation until it reaches its intended location. Once delivered, a substation converts the power to a 115 kilovolt-level that is used in most homes and businesses.
PG&E is proposing to build a third substation in North San Jose — PG&E’s calling it Los Esteros — as well as a host of new transmission lines in that area to boost its ability to draw power from the state electricity grid.
The project would expand Silicon Valley’s current capacity by 800 megawatts, or more than 30 percent. It includes extending a 230 kilovolt line from the Newark substation to the Los Esteros substation and new 115 kilovolt lines to Fremont, Milpitas, and through North San Jose into Sunnyvale.
However, that $84.6 million project has been held up in the chambers of the California Public Utilities Commission for more than two years and wouldn’t come online until the summer of 2003 at the earliest. Questions regarding whether to route the transmission lines above ground or underground, as well as aesthetic issues at the 21-acre Los Esteros site, have hindered construction.
The project is not related to the 180-megawatt Los Esteros power plant planned in the same general area by Calpine Corp., although Calpine chose that site in part because of PG&E plans to build the substation there, company officials say.
Despite its differences over design and infrastructure, the utilities commission and PG&E agree that the substation is needed.
“The need for [Los Esteros] project is strong,” says CPUC regulatory analyst Brad Wetstone. “It’s bringing power closer to the San Jose power demand.”
The June 14, 2000, blackouts in Silicon Valley that heralded the beginning of California’s energy crisis were caused when transmission lines became overextended and the California Independent System Operator was unable to send more power here. In other words, there was enough power available but no way to get it into Silicon Valley, Mr. Bradley says.
“We don’t have enough transmission lines into Silicon Valley,” says Jeff Smith, a Pacific Gas & Electric Co. spokesman. ”[Los Esteros] gives us another vital link to [the state’s grid system].”
The blackout potential is real enough that PG&E called upon five flatbed trucks to bring a 417-ton transformer from Folsom to its Newark substation to act as a backup should anything break down at that facility this summer, Mr. Smith says.
PG&E does have a small substation west of Saratoga and a Hayward substation that provides power to San Mateo County that also can route power to the South Bay in an emergency.
But rerouting power through these substations would represent little more than a stopgap solution, Mr. Smith says.
Copyright 2002 American City Business Journals Inc.
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