Last week's power outage in the Northeastern United States is reminiscent of the blackout Dec. 8, 1998, on the San Francisco Peninsula that affected nearly a million people. That blackout, as did the one in the Northeast, resulted from the simultaneous loss of several transmission lines.

Five years later, San Francisco still remains the most vulnerable part of the statewide electrical grid. Part of the vulnerability results from San Francisco's location at the tip of a peninsula, with power flowing into the city over just one transmission pathway. The vulnerability is heightened by the obsolescence of the two power plants located in the city.

Recognizing that vulnerability, the city and county of San Francisco and PG&E are taking immediate steps to improve reliability of the existing electrical system. Improving long-term electricity security, however, requires a new approach to electricity investments and planning.

To improve electrical reliability in the near term, the city will install by the summer of 2005 four new, smaller and more efficient power plants in San Francisco. They will allow PG&E to retire the unreliable 44-year-old power plant at Hunters Point. At the same time PG&E, is securing a license from the California Public Utilities Commission to build a new 27-mile transmission line in San Mateo County that will create a second independent transmission pathway for electricity delivered to San Francisco. This transmission project creates a more diverse transmission system for the upper peninsula and significantly reduces the risk of a repetition of the 1998 outage.

But by itself, this new pathway does not allow more electricity to be imported into San Francisco. To bring more power into San Francisco, PG&E must either build new underground cables in the city or operate the existing cables closer to their safety limits. The existing underground cables are capable of delivering more power for short periods. A cascading failure of several underground cables, however, could result in a prolonged power outage. (This occurred in Auckland, New Zealand, in 1998, when the loss of four underground cables blacked out the city's downtown for five weeks.)

A new approach to electricity planning will decrease San Francisco's reliance on aging underground cables and other vulnerable parts of the Bay Area grid. We need to reverse the industry-wide trend of delivering increasing quantities of power over longer distances on high-voltage transmission lines --

a build-up that raises the likelihood of large-scale failures. The long-term solution is to integrate smaller, modular and redundant electrical devices on the grid close to the consumers they serve.

New technologies such as fuel cells, small combined heat and power systems, solar panels, flywheel batteries and ultracapacitors are now entering the power market and have the potential to provide cheaper, more reliable electricity than the highly centralized power grid. But to be used effectively,

these technologies need to be integrated into a much more responsive electrical grid that is more like the Internet than the current system.

The constantly changing demand for power requires a complex balancing of voltage, power and frequency of the electric system. Now, this delicate balance is highly centralized and is achieved mostly by adjusting the operation of large power plants. In the not too distant future, advances in information systems will allow many homes, businesses and industries to be equipped to react in real time to changing conditions on the grid. A grid that accommodates responsive customers will be more resilient, more economical and better for the environment.

Last December, the San Francisco Board of Supervisors adopted a 10-year electricity resource plan, which calls for meeting 20 percent of San Francisco's forecasted need for electricity by 2012 through improved efficiency, load management and advanced and renewable technologies. The recent blackout in the Northeast reinforces the urgency of following through on the implementation of this ambitious plan.

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Find out more
The public can learn more about San Francisco's proposal to install four smaller power plants in the city at four meetings over the next month.

When: Aug. 28 at 7 p.m.; Sept. 4 at noon; Sept. 9 at 6:30 p.m.; and Sept. 20 at 10 a.m.

Where: various locations in San Francisco

More information: Visit www.sfwater.org or call (415) 554-3289 for locations and details.

Ed Smeloff is assistant general manager for power policy and planning at the San Francisco Public Utilities Commission.