Power Reliability Is Project Objective

• Underground Line Will Improve Link to Ocean System

BY HANS LAETZ

The underground power line project that will cause Pacific Coast Highway to be dug up near Malibu will be an important reliability link for the entire West Coast electrical grid, Los Angeles Department of Water and Power officials say.

The new power line will allow better grounding for the Pacific DC Intertie: the 500-kilovolt, direct-current circuit that carries vast amounts of electricity back and forth between Washington state and the Los Angeles area.

During the summer, surplus electricity from the Northwest flows south to keep California cool, and is sold to several Southland utilities. In the winter, surplus power from warmer climes helps heat Washington and Oregon.

The giant powerline parallels US 395, and by using DC it can carry more than twice the load of other high-tension lines that bring electricity to the Southland using AC—alternating current. DC lines need to be grounded, and only the Pacific Ocean is big enough to properly ground a power line this enormous, engineers say.

By improving the link to an existing grounding system in Santa Monica Bay, the intertie will operate more reliably and efficiently.

As planned, the expanded line will go out to sea near PCH at Sunset Boulevard, and terminate at existing large underwater electrodes.

These electrodes sit in a concrete cage, about a meter above the seafloor, and dissipate energy into ocean water without affecting sea creatures or people, DWP officials say.