A photo taken in late February by members of Basin and Range Watch points up a persistent problem with siting utility-scale solar facilities in the desert: once disturbed by construction, desert soils can loose huge amounts of particulate matter into the air.
Posted to the group's Facebook page on Monday, the photo appeared with a caption reading:
We were told by the California Energy Commission, the Bureau of Land Management and BrightSource Energy that dust emissions on their Ivanpah Project in San Bernardino County, CA are under control. This is a photo of the Ivanpah 1 power block on February 23, 2013 on a windy day.
Ivanpah was far from the only place venting dust into the wind on February 23: on that same day in Joshua Tree National Park, visibility was cut severely as northerly winds blew fine sediments off the Johnson Valley Off-Road Vehicle area.
But Ivanpah's builder, Oakland-based BrightSource Energy, has maintained that its method of construction of its Ivanpah Solar Electric Generating System would minimize the kind of disturbance to the soil likely to result in dust problems. The plant's three 459-foot power towers are surrounded by thousands of mirrored heliostats, but rather than grading the land to mount those garage-door-sized mirrors BrightSource installed them on pylons pile-driven into the ground. Vegetation surrounding the heliostats was trimmed rather than bulldozed away, according to the company, and the remaining roots were expected to hold the soil in place where bulldozing would have left the soil vulnerable to wind erosion.
Wind-driven erosion of dust can affect wildlife and plants, even interfering with pollination. But dust means more than an environmental threat: it's a public health threat as well. Desert soils are known to harbor the spores of Valley Fever, a respiratory ailment that disproportionately affects the poor, and to which certain ethnic groups seem to suffer a genetic vulnerability. Even without pathogens, the fine suspended dust particles are hazardous to children, the elderly, and people with existing respiratory problems. Particulate matter pollution is strictly regulated by the state of California, and some of the worst "non-attainment areas" in the state are in the deserts. That's precisely because desert soils are so ready to give up dust once disturbed.
It's unknown whether the dust shown in the Basin and Range Watch photo blew off the land with the "trimmed" vegetation, or off the network of access roads that crisscross the facility. Either way, based on ReWire's months of experience witnessing wind storms in the Ivanpah Valley before construction began, dust storms like that did not occur very often on the site before construction.
BrightSource representatives contacted by ReWire declined to offer comment on the photo. That may be due to having a full agenda for the last couple of days: on Wednesday, the plant focused more than a thousand heliostats on the boiler atop Unit 1's tower, the first time the project has directed concentrated solar radiation at one of the boilers. The resulting "solar flux" heated water in the boiler to just below the point of steam generation. Further tests will "stress test" the unit's hydraulics for pressure-worthiness. According to BrightSource, the 377-megawatt plant, covering about 3,500 acres of public lands, is 84 percent complete.