L.A.'s two major power utilities are betting big on an unlikely source: wind energy.

For years, the utilities treated wind power more like a novelty, making token investments in a technology they considered not ready for prime time. But as prices for fossil fuels for conventional power plants have soared and the cost or availability of other forms of renewable energy remain out of reach, the cost for wind power has fallen and is now more competitive with traditional power sources.

That has prompted Southern California Edison, a subsidiary of Rosemead-based Edison International, and the Los Angeles Department of Water & Power to move ahead with two major wind projects as they strive to meet stiff mandates for renewable power in their portfolios.

Edison announced earlier this month that it would build a massive transmission line to carry power from existing and planned wind power projects in the Tehachapi Mountains to its Los Angeles-area power grid. Two months ago, the DWP broke ground on the largest city-owned wind farm in the nation, also situated in the Tehachapis, which are fast emerging as the prime wind power region in California.

"Wind power will now become a significant part of the Southern California marketplace," said C.P. "Case" Van Dam, professor of mechanical and aeronautical engineering at the University of California, Davis, and co-director of the California Wind Energy Collaborative, an industry research group.

Behind this push for wind power is a mandate that utilities in California have 20 percent of their power portfolios coming from renewable (non-fossil fuel) resources by 2010. Edison currently gets about 17 percent of its energy from renewable resources, most of it geothermal. Only 3 percent of its total electricity portfolio comes from wind power.

The DWP lags behind Edison, with about 8 percent of its portfolio coming from renewable sources and less than 1 percent from wind power. The agency has come under pressure from Mayor Antonio Villaraigosa and environmental activists to step up its pace of obtaining renewable energy sources. Villaraigosa has set a goal of 20 percent renewables by 2010 and 35 percent by 2020.

As these utilities come under increasing pressure to beef up their supplies of renewable energy, wind power has emerged as the new favorite. That's because improved technology has brought down the kilowatt-hour production cost, and it's also comparatively easy and quick to set up wind farms.

Production costs have plunged from 80 cents per kilowatt hour 25 years ago to well under 10 cents per kilowatt hour today as wind turbines have become much more efficient. That's now comparable with production costs from conventional natural gas-fired plants; those costs have been rising sharply as natural gas prices have soared.

Back in the early 1980s, during the first wind power rush, the turbine rotors were only about 50 feet across and generated a maximum of 100 kilowatts. With the advent of lighter materials and a better understanding of wind flows, today's blades are as long as 300 feet across, giving them much more wind energy to collect. These new turbines can generate up to 1.5 megawatts 15 times the amount of power as their predecessors.

"With this level of efficiency, wind energy today is the cheapest resource to build new power generation," said Jim Caldwell, assistant general manager of environmental affairs for the Los Angeles Department of Water & Power.

He added that wind turbines are the quickest and easiest to set up and get permitted among all the options for new power generation.

Higher-cost alternatives

Costs for other forms of renewable power remain stubbornly high. Solar power, for example, ranges from 25 cents to 35 cents per kilowatt-hour for conventional photovoltaic panels. In recent years, new mirror-array technology has been developed that can produce electricity at between 9 cents and 12 cents per kilowatt-hour, but it's still so new that it has yet to be applied on a large scale.

Geothermal energy, which now accounts for 60 percent of Edison's renewable energy portfolio and 40 percent of the overall state renewable portfolio, can be produced as cheaply as power from a natural gas-fired plant. But it's a limited resource. The closest geothermal fields to the Los Angeles basin are near the Salton Sea and are nearly tapped out. A much smaller field is in the Mammoth area; DWP, which has nearby power lines, is considering tapping into it. "But this would be only a small drop in the bucket," of the agency's overall power supply, Caldwell said.

Likewise, biomass projects that convert decaying matter into energy generally tend to be small scale, since their size is limited by the size of the adjacent landfills.

But wind power still faces significant hurdles. Because it's an intermittent source of energy that works best when the wind blows at about 40 miles per hour, the turbines only generate electricity about half the time. Therefore, wind energy must always be complemented with other power sources.

More importantly, though, a lack of transmission lines has limited wind power production from Southern California's most potentially lucrative wind region: the Tehachapi Mountain range and adjacent area in the northwest corner of the Mojave Desert. ("Tehachapi" in one local Native American language means "strong wind.")

Because of the zone's remoteness, rough terrain and sparse population, both Edison and the DWP each have only one modest transmission line running through the region. Edison's line is already at capacity.

"There's a real bottleneck developing there," said the Wind Collaborative's Van Dam.

Indeed, in December 2006, when the utility signed a contract with Alta Windpower Development LLC, a subsidiary of Sydney, Australia-based Allco Finance Group Ltd., for 1,500 megawatts to be delivered to the Edison grid, it was stipulated that the power could not be delivered until a long-awaited transmission upgrade was completed. (A megawatt can power about 700 single-family homes.)

With the $1.8 billion transmission upgrade announced March 7, that power is now set to be delivered starting in 2013. In the meantime, according to Stuart Hemphill, vice president of renewable and alternative power for Edison, the utility plans to solicit bids for further wind and alternative energy projects that could take up the remaining capacity on the planned transmission line, which will have a capacity of 4,500 megawatts.

While the DWP's existing transmission line through the Tehachapi area will be able to handle the power from the 120-megawatt, $425 million Pine Tree wind farm that broke ground earlier this year, it won't be able to handle two even more massive projects the L.A. agency has planned.

The DWP has already acquired 12,000 adjacent acres for the Pine Canyon wind farm that would generate 150 megawatts of electricity. And utility officials said they are in negotiations to purchase an additional 33,000 acres of land nearby that would also be used as a wind farm.

"Our plans are to have at least 500 megawatts of wind power flowing from that area by 2013," Caldwell said.

All told, the two utilities plan to have at least 3,000 megawatts of wind power coming in from the Tehachapi area, effectively tripling the current amount of wind power in their two systems.

"Wind power will be the fastest growing component of our power supply," Caldwell said.

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