Far from the “28,000 fried birds!!” touted by desert solar opponents, the Ivanpah solar power tower project yielded only 695 actual avian detections in its first year of operations.

Far from the “28,000 fried birds!!” touted by desert solar opponents, the Ivanpah solar power tower project yielded only 695 actual avian detections in its first year of operations. An annual fatality estimate of 3,504 for the first year was arrived at as a result of the rigorous environmental reporting required by the state of California of large solar projects like the 392 MW Ivanpah Concentrated Solar Power (CSP) Plant.

According to the independent environmental monitoring firm HT Harvey & Associates, there were 695 “avian detections” and another 8 injured birds found over the first four seasons, from October of 2013 (during the initial pre-production commissioning) and October of 2014.

“Avian detections” are not necessarily dead birds but rather presumed fatalities based on feather spots on the ground from which assumptions and estimates are made, to arrive at the estimate for the year of 3,504.

Potential for overestimate

However, in the Ivanpah Solar Electric Generating System Avian & Bat Technical Advisory Committee (TAC) Meeting on March 6, 2015, in response to a question from the California Energy Commission (CEC), HT Harvey noted that there was more chance of overestimating fatalities than of underestimating them. For example, the modeling estimates did not consider that multiple feather spots could be from a single bird.

“HT Harvey & Associates explained that the estimator model accounts for potential under-counting. However, the estimator does not account for the potential for over-counting, where more than one feather spot could occur from a single fatality.”

So, the approximately 3,500 figure for estimated fatalities from the 695 ‘avian detections’ (birds or feather spots) is very probably on the high side.

So why has “bird-killing solar” fallen so far short of the much touted 28,000?

Engineering solutions are not beyond the imagination of those in the clean energy world, something opponents overlooked.

“It’s mind-numbingly simple to just set the heliostats into more varying angles when going into standby rather than creating a ‘false target’ in mid air just away from the receiver that — until it turned out to have this effect — was a seemingly practical practice,” says former Abengoa Solar COO Scott Frier.

“They merely need to angle the heliostats into non-transecting beams, thus creating a single sun reflection into space.”

Solar engineers are not the only ones able to adapt to solve problems:

Birds also learned — to fly around the project

Birds learned to fly around Ivanpah

Over the year’s observations, there were approximately five times as many birds and species sighted by biologists outside in the desert next to the facility, an equal-sized control area termed the “desert bajada” grids  — as were sighted within the heliostat grids.

“As with species richness, avian abundance was highest in the two desert bajada grids in all seasons (1,988 total observations) and substantially lower on the three heliostat grids (363 total observations).

“The extent of area surveyed was identical for the two habitats (40 points in each habitat). Thus, comparison of general avian abundance metrics such as total observations, as was done above, is appropriate for elucidating relative abundance, both overall and by species.”

The first commercial solar power towers were built in Spain. Masdar was part of the consortium that helped develop Gemasolar in Spain; a much smaller project at 20 MW but with 15 hours of storage.

When I spoke to Nicolas Calvet, who leads the thermal energy storage group at the Masdar Institute of Science and Technology, he appeared to be confused by Ivanpah’s problems, but apparently because Spain’s solar power tower CSP plants have had no incidence of avian mortality.

“No; I heard the story of birds in America,” said Calvet in his charming French accent.

“I think it’s ridiculous. We have plenty of birds at the beam down. The problem is they are shitting on our solar receiver, and I can tell you they are not dead at all. They are in good health. And if you have occasion to come and visit our plant you will see we have lots of birds and they are very happy. We haven’t had any dead birds at Gemasolar.”

The inclusion of storage does also contribute to preventing avian mortality by reducing the need for standby heliostat focus during the day. It is only standby points that are a potential danger, and only when 3,000 “suns” worth of mirrors are focused any one point. This is easily avoidable.

Regulators slowed deterrent implementation

Ivanpah owners NRG Energy and BrightSource Energy began testing of heliostat diffusion in July. But permission to test various other options they proposed appears to have been granted quite slowly and in a piecemeal way, judging by the laborious process revealed by the various TAC meeting notes at the CEC going back over the year.

It appears as if regulators are trying to create a control case to see what might be the worst case scenario for such a plant before actually letting the owners tackle the problem. For example, the sonic deterrents being examined were first proposed by the owners last spring and have only just this month been approved for testing, after the end of the first year’s study.

“CEC suggested that the deterrence system be installed in Unit 3 to be able to discern the effects from an existing test in Unit 1 of the chemosensory deterrent.

“The project explained that the sonic test deterrent is intended to affect migratory birds, whereas the chemosensory deterrent is intended to affect resident birds, so different groups of birds populations are targeted by each deterrent. The use of both deterrents at Unit 1 is expected to provide greater statistical power for reductions in mortality in comparison to other units and to previous monitoring at Unit 1.Thus, Unit 1 was proposed instead of Unit 3, where mortalities are lower. The project would also like to test a complementary suite of deterrents at one location and not confound the existing surveys at the other units. TAC concurs with testing at Unit 1.”

But, the project has been permitted to replace lighting with LEDs and to contain waste and water to reduce attractions like food and water.

No endangered species

Not only does the final count fall far short of opponents’ hopes, but the assortment of birds represented in the detections also will fail to satisfy, with virtually no endangered species in the lot, as noted by the report.

“Species most recorded as a detection was the mourning dove, with a total of 412 detections (118 fatalities from known causes and 294 from unknown causes). This represents 0.00011% of the mourning doves North American population (349 million) and 0.0029% of the annual take by hunters (14.5 million mourning doves).

“Total detections (and fatality estimates) of any one species represent a small proportion of local, regional, or national populations.

“Avian detections at the site included 83 different bird species with 64 having fewer than 10 detections. Of the remaining 19 species, all have populations that are great enough locally (either as breeders, wintering birds, or migrants), regionally, and nationally that the magnitude of mortality detected and/or estimated at Ivanpah during the first four seasons of monitoring would have a minimal impact on populations at any of these geographic scales.

“Furthermore, the cause of death for 42.2% of the detections of species with 10 or more detections was unknown and thus cannot be determined with certainty to have been ‘facility-caused.’ “

Most of the large birds (65%) were ravens, which are routinely poisoned by the thousands at landfills, to no objection by the people claiming that advanced solar energy is such a dreadful threat.

“They’re flying rats. They’re nasty birds. They hang out on top of the equipment. If unchecked they get out of control,” Doug “Stretch” Baker at the Tonopah Landfill related.

“If 200 birds roost on the same piece of equipment, the guys can’t hardly clear the poop off the window, because it’s so nasty when they’re roosting there; it gets stuck on the things so bad. The worst issue we have with birds are the European starlings. The DRC-1339 — that’s the poison that’s used here — is specially engineered, and they just lay down and go to sleep.”