SunCatcher Noise May Sink CO Project

Pilot SunCatcher plant (slv renewable communities alliance photo)

It would be a noisy Space Age intrusion in one of Colorado’s last pure Old West landscapes, and more industrialization would  follow it into the northern San Luis Valley.

Except for a couple of protestors yelling about jobs, most of the estimated 150 people in the packed crowd of Saguache County ranchers, retirees and quiescent Crestonians raised their voices against it.

The applicants antagonized them with a trust-us-now, ask-questions-later attitude. Their scientific experts failed to prove they had spent much time, if any, at the site. Aware they will have to make a decision in a few weeks, the Saguache County Commission sat in silence except for the chairman’s angry attempts to hurry things along.

The Dec. 6 hearing in the county court house on the application by Tessera Solar North America was recessed after six contentious hours, to be continued at a date not yet announced. The Houston-based company seeks a permit under Colorado’s “1041” law on local development to install about 5,800 innovative “SunCatchers” on about 1,500 acres of ranch land between U.S. 285 and State Highway 17 south of the town of Saguache.

The relatively low-output project (145 megawatts, or one third of 1 percent of the coal-fired Farmington, NM, plants) is a response to Colorado legislation forcing electric utilities to go 20 per cent green. But so far no power purchase agreements have been signed.

A SunCatcher is based on an invention two centuries ago by a Scot named Stirling – an engine driven by the rapid heating and cooling (and therefore expansion and contraction) of a gas in sealed cylinders. In this application each four-cylinder  engine turns a small generator. The heat source is a 30-foot parabolic dish aimed at the sun. The gas is hydrogen, which is explosive.

The works at the focal point of each dish would make noise, and a recording of the sound played at the hearing was grating. Few technical data were presented.  Tessera representatives even puzzled knowledgeable listeners by promising to put mufflers on the closed-system engines (no exhaust), and permit manager Richard Knox admitted he “misspoke” when he said engines were turbines.

Tessera consultant Matt Jones, who had just flown in from Los Angeles, engaged in a long abstract discourse on mathematical modeling of theoretical acoustical effects at the site, according to maps.  Interrupted by a member of the crowd asking if the plant would be heard at the nearby town of Moffat, he responded, “Where?”

Jones and a consultant hired by the county dueled decibels for an hour without resolving the questions: how loud will 5,800 of these engines be at various distances under various climate conditions and will they violate the state noise-nuisance statute? Vince Palermo of Crestone, who has raised the noise issue with some expertise at previous hearings, dismissed the colloquy as “bullshit,” drawing some applause.

Commission chair Sam Pace, however, summarized that both sides seemed to agree the plant very likely would produce about 65 decibels of noise at the property boundary. If so, this would be in violation of the Colorado noise ordinance for residential environments. But, as they say in philosophy 101, what is the sound of a tree falling in the forest if nobody is there to hear it? More to come. . .

Knox had one obvious reassurance: the plant would not operate at night! So, “There will be no noise except a security guard closing a door.” His reliance on imagery (“We’ll sharpen the pencil on this.”) sometimes brought derisive laughter, as when he called the SunCatcher array an “orchard.”

Knox and a company executive determined later to be Randy Etheridge estimated the plant would afford up to 50 permanent jobs, but they could not classify them at this time. Knox said there would be employment for you “if you can work on an engine, if you can wash windows.” Etheridge said there would be a need for skilled controllers and for maintenance workers “not just washing windows.”

The two officers declined to answer funding questions, although Etheridge said, “We will be applying for some of the DOE (Department of Energy) funds that are out there.” Ceal Smith, chair of an organization opposing the project, said later the main funding for similar ventures  expires at the end of the year. Etheridge brushed her off during a brief break, declining to give his name (“You can call me anything you want.”) He left two hours before the hearing recessed.

The two leading points to be considered under the 1401 statute are, first, the health, welfare and safety of the residents and, second, the effects on the environment, both natural and human.

Hydrogen, the lightest element, dissipates even through metal, so the Stirling engines will need constant hydrogen feeds. The safety of hydrogen processing was questioned by a scientifically trained resident named Larry Ewing. “How are you going to generate hydrogen?” he asked. Knox, conceding  “I’m not the hydrogen guy,” wondered why that was important. Ewing said it was important because a caustic fluid is used in one process and others are also dangerous.  After some argument, Ewing concluded, “The bottom line is you don’t know what you’re going to do.” Knox admitted it, saying, “Correct.”

When Knox read from his Powerpoint that there were “no listed fauna or flora or their associated habitats on the project site,” a woman in the crowd drew applause and laughter when she said, “Does that include cows?”

Rancher John Warner, who has 2,000 acres north of the site, objected to the presentation statement that human impact had been considered and would be mitigated satisfactorily. “Nobody came to me and asked anything about it,” Warner said.

Knox got into trouble when he responded that the point was based on typical studies. “While your ranching activity is important to your world,” he began, but was drowned out by groans from the crowd. “We knew this about you before talking to you,” Knox said. “The point is we have analyzed the visual impact for hundreds of projects.”

Local people who have lived with the capricious weather of the San Luis Valley for decades brought up other questions that the Tessera people could not answer:

– Since the only actual experience with SunCatchers is the test array at temperate Phoenix,  how can it be determined how they would work at 20-below-zero temperatures here?

– SunCatchers have to be folded when winds exceed 35 miles an hour, but the process takes eight minutes – enough warning time for valley gusts and dust devils?

– In response to a finding of “no evidence of standing water during the growing season” at the site, Virginia Sutherland showed a panoramic photo of her normally dry looking pasture in 1997 – a lake. Is it feasible to generate electricity while standing in water?

The potentially disabling issue of wetlands at the site was brought up by Jenny Nehring, a wildlife biologist from Monte Vista concerned about the valley’s bird refuges. Tessera has marked water drainages in blue on its rough map of the development, but Nehring maintains that doesn’t tell the whole story.

The hired consultant, Ecosphere of Durango, said in its report: “Assuming that the wetlands as preliminarily identified are correct, the project appears to avoid significant impact to wetlands.” Nehring says to arrive at this finding Ecosphere had to ignore the hydrous soils at the site as well as decades of Corps of Engineers reports.

“You continue to dismiss decade after decade of wetlands inventories,” she told Knox from the audience.

“We still have work to do,” he responded.

In a brief interview, Nehring elaborated: “Water has changed in the valley in the very recent past, and it is going to change dramatically in the future.”  One change will be increased annual deliveries of water beginning in 2012.

Section 404 of the federal Clean Water Act requires a permit from the Corps of Engineers before virtually any disturbance of wetlands. And any disturbance must be mitigated by replacement of lost wetlands, acre for acre. This could be costly for Tessera if the Ecosphere finding is insufficient. Nehring said Tessera would be wise to apply for a 404 permit . . . now.

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