Sunday, March 4, 2012

ENERGY: Birds Big Concern for Solar Project

A solar energy company wants to blanket nearly 12 square miles of desert in eastern Riverside County with 85,000 mirrors and three skyscraping towers, the latest in a series of renewable energy mega-developments to ignite anticipation and worry.
Colorado River at the west boundary of Cibola Wildlife Refuge south of Blythe.

BrightSource Energy Co.’s Rio Mesa solar farm would cover a plateau above the Palo Verde Valley farming area five miles from the Colorado River. The mirrors would focus the sun’s energy on the 760-foot-tall towers, creating steam to generate electricity.

At peak capacity, it could produce about 750 megawatts of clean energy, enough to power an estimated 300,000 homes. Four commercial-scale solar energy projects under construction in Riverside and San Bernardino counties are expected to help California meet its renewable energy goal: 33 percent by 2020.

With a promise of 2,500 construction jobs and about 150 permanent positions, the $3 billion Rio Mesa development has enthusiastic backing from labor unions and from civic leaders and many residents in the nearby town of Blythe. The city’s unemployment rate is about 15 percent, and the median household brings in less than $42,000.

But questions linger about whether the technology would harm birds in an important avian flyway that parallels the river. Some biologists are concerned that the tremendous heat involved in the technology will burn birds on the wing.

State energy officials will host a meeting focusing on such questions Monday in Sacramento. Officials from the company and state and federal wildlife agencies are expected to hash out what additional studies are needed to determine how the Rio Mesa project would affect wildlife.


Eddy Caldera, 44, a cook at a Blythe restaurant, attended a bus tour of the Rio Mesa site that BrightSource hosted earlier this month. He said he was born on a bridge in the farming area just two miles to the east when his mother couldn’t get to the hospital in time.

Caldera said he can’t wait to give up his apron to take a job maintaining the mirrors, called heliostats, at Rio Mesa or another solar energy project. He recently completed a community college class and earned certification for such work. As the tour bus crossed his birthplace, he eagerly explained how the mirrors are kept clean with special high-pressure sprayers that minimize the use of water.

“I want to operate the cleaning machine,” he said.

Significant hurdles still face BrightSource. The company was first out of the gate in the current solar-energy rush with its Ivanpah solar array now under construction near Primm, Nev. That development has encountered delays because of wildlife issues — specifically desert tortoises, a protected species found in far greater numbers than the company estimated.

The Rio Mesa project, to be built on land mostly owned by Metropolitan Water District of Southern California, must go through comprehensive environmental reviews before the California Energy Commission can decide to permit it. BrightSource also needs a federal right-of-way grant for 1,600 acres under the jurisdiction of the U.S. Bureau of Land Management.

The big issue is how the technology could affect winged life.

Migratory birds “may be burned as a result of flying through the heat beams transmitted by the heliostats,” according to a Dec. 16 letter to the California Energy Commission from members of a task force consisting of biology staff with the U.S. Fish and Wildlife Service, California Department of Fish and Game, U.S. Bureau of Land Management and the commission.

Another concern is the mirrors themselves. Birds often have trouble distinguishing reflective surfaces and crash into them, dying from broken wings and other injuries.

The inter-agency task force is calling for a year of study and site surveys to determine what species and how many birds might be harmed.

BrightSource officials declined to be interviewed for this story. Kristen Hunter, a company spokeswoman, said in an email that BrightSource has completed several bird surveys and would work collaboratively with state and federal wildlife officials to determine what additional information should be gathered.

Hunter’s email also said boilers located atop the towers would be designed to absorb heat, reducing potential harm to birds.

During the recent site tour, the company’s project manager, Todd Stewart, noted that helicopter surveys found the nearest golden eagle nest a little more than six miles away, and it was inactive.


The Rio Mesa site is at the edge of the Colorado River valley, which the Audubon Society has dubbed a Globally Important Bird Area. It is a little more than five miles from Cibola National Wildlife Refuge, on the Arizona side of the river, one of four national wildlife refuges in the lower Colorado River valley.

The Cibola refuge boasts 288 bird species ranging from sparrows and barn swallows to Canada geese and golden eagles. Tens of thousands of birds fly along the river’s route on any given day.

Bob McKernan is director of the San Bernardino County Museum and an expert who has studied the birdlife in the river valley.

The river is a geological marker that guides birds on their spring and fall migrations and provides water, food and shelter for migrant and residents, McKernan said. Nearby farms fields also attract birds, he said.

In the late 1980s, McKernan and his colleagues counted an average of 7,700 birds an hour crossing a one-mile line straddling the river about five miles north of Blythe during a migration season. The peak was about 20,000 birds an hour, he said.

Birds traveling the river route use a wide swath, going as far west as Desert Center, about 45 miles from the river, McKernan said. The Rio Mesa towers would only be a tiny point in that vast area, he said.

McKernan co-wrote the only known study of how power towers like those planned at Rio Mesa affect birds in Southern California. In the early 1980s, the authors tracked bird deaths for 10 months at Southern California Edison’s now-defunct Solar One project in the Daggett area east of Barstow. At 10 megawatts, the solar installation was tiny in comparison to Rio Mesa.

Results published in 1986 in the Journal of Field Ornithology found that 70 birds representing 26 species died. Most — 57 — died by crashing into mirrors and other structures. The other 13 were burned by the heat beams the mirrors focused on the tower. The authors concluded that the effect on bird life was minimal. But they also said such projects should avoid locating near farm fields or water bodies that attract birds.

As for Rio Mesa, McKernan said wildlife biologists should survey the Rio Mesa site for a year, because different species migrate at different times.

Hunter’s email said the Solar One site attracted more birds than the Rio Mesa area because of its proximity to 80 acres of evaporation ponds. She also said the Rio Mesa mirrors won’t stand as tall, reducing the potential for bird collisions.

Beyond wildlife, the environmental review will cover air quality, water use and Native American and other cultural resources.


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