From above, the Ivanpah Solar Electric Generating System looks like a vision from the future: more than 173,000 curved mirrors that automatically track the sun spread out over five-and-a-half square miles of otherwise barren, ochre-colored desert. Arranged in massive, overlapping circles, these mirrors, which are called heliostats, focus their rays on one of the three 500-foot “power towers” erected at the center of the sphere. From afar, the intensity of the reflected sun makes the entire installation, located in the steaming Mojave Desert, some 40 miles southwest of Las Vegas, glow despite the already blinding desert light.
Since it began commercial operation in late 2013, the $2.2 billion Ivanpah was supposed to light the way to a brighter energy future. The technology it employs, called concentrated solar power (CSP), or solar thermal energy, was considered a game-changer. And Ivanpah was the largest plant of its type ever attempted.
In 2010, President Obama touted the project, which was expected to power 140,000 homes in California, as “the largest such plant in the world,” beating out the likes of those in China and India. At its ribbon cutting ceremony in February of last year, United States Secretary of Energy Ernest Moniz called it “a shining example of how America is becoming a world leader in solar energy.”
So far, though, Ivanpah has struggled to live up to the hype. When the plans were first laid, BrightSource Energy Inc., the project’s lead developer, predicted that production could begin as early as 2011. Power didn’t begin to flow until almost three years later. (BrightSource, however, insists Ivanpah was delivered on time and on budget.) And even when it did finally begin producing energy, the plant was putting out about half of the electricity designers had initially predicted for its first year, though performance has improved of late.
Ivanpah’s image as a model of clean energy production has also been singed by a growing tally of dead birds, which ignite as they fly through the powerful solar beams; mid-day temperature in the Mojave Desert can reach 120 degrees Fahrenheit.
Because Ivanpah was the object of such high hopes, its early struggles have dimmed expectations for concentrated solar power in general. “I think CSP is on its last leg,” says Adam Schultz, program manager for the University of California–Davis Energy Institute, and former senior analyst at the California Public Utilities Commission. Compared with the cost of other renewable energy sources, he says, CSP is just too expensive.
This wasn’t supposed to be the fate of concentrated solar power. A decade ago, as the world began to awake to the perils of climate change, CSP technology was heralded as a potential savior. As the sun’s rays are reflected by the mirrors to a single point in one of the towers, the searing temperatures can reach 800 degrees Fahrenheit, heating water or, in some cases, molten salt. In turn, this creates steam that spins a turbine that generates electricity.
CSP plants, it was thought, could dot the desert terrain that stretches across Arizona, Nevada, and California, turning what many had considered an economic wasteland into a valuable natural resource. Even more attractive was the fact that CSP uses minimal amounts of water and doesn’t throw off any carbon emissions.
Though some form of CSP technology has been around for decades, a new generation of these installations began to pop up over the last 10 years. But no one had attempted anything on the order of Ivanpah. Named after a now-dry nearby lake, the plant’s three power towers were supposed to produce one million megawatt hours of electricity a year—roughly enough to power a small city.
When Ivanpah was first proposed in 2007, it lined a group of blue-chip investors’ pockets, including BrightSource; Google, Inc.; and NRG Energy.
But the developers soon ran into hurdles. The process of acquiring all the necessary permits for land use and environmental certifications was long. The Department of Energy spent over four years evaluating the project before green-lighting a crucial $1.6 billion loan guarantee, though an Ivanpah manager says the process was “thorough and thoughtful.” The longer the hoop-jumping took, the longer investors had to wait before they could pull in any revenue.
As the years dragged on, and Ivanpah still wasn’t operational, it began to run up against another problem: the falling price of photovoltaic power. Photovoltaics, the most widely used form of solar energy, are panels usually made with silicon and other components that turn the sun’s light directly into electricity—the same technology employed in rooftop solar panels. The current cost of photovoltaics in the U.S. is between $1.58 and $1.80 per watt, down from more than $5 just five years ago. Though experts from the non-profit Solar Energy Industries Association insist there is no direct apples-to-apples comparison between the two technologies, a CSP plant such as Ivanpah costs about $5.61 per watt.
While the declining cost of renewables is good news, it was close to a death knell for concentrated solar power, which is now comparatively more expensive. Because CSP’s technology is simple—reflecting mirrors and metal towers—it wasn’t able to keep up with the pace of improvements in photovoltaic power. “There aren’t huge breakthroughs for steel and glass,” U.C. Davis’ Schultz says.
Additionally, when electricity finally began to trickle out of Ivanpah in 2013, the plant proved to be lethal to surrounding wildlife. According to scientific observers from the Department of Energy who studied the plant, bursts of smoke can be seen roughly every two minutes as birds, insects, or other objects cross the mirror’s intense rays. It happens with such frequency that plant workers developed their own term for the phenomenon: “streamers,” so called for the trail of smoke left in the burnt feathers’ wake. Scientists call it “solar flux.”
Ivanpah commissioned an environmental review of the issue in 2013, which classified the impact to avian life as “low.”
“Birds dying from solar flux is unique to [CSP] technology,” says Magdalena Rodriguez, a senior environmental scientist with the California Department of Fish and Wildlife, though she added that there are rare instances of birds perishing near photovoltaic panel arrays as well. Her office has been working with the plant on mitigation techniques, such as sonic deterrents for bats and “anti-perch devices,” as Rodriguez calls them, on the power towers. They are now using canines to sniff out bird carcasses among the mirrors in order to get a more accurate account of the fatalities.
As mentioned, power production in Ivanpah’s first year was only 50 percent of its expected capacity, though Joseph Desmond, a member of BrightSource’s board of directors, said that it was never their expectation for it to reach its full level in the first year. “It is premature to draw any sort of conclusion,” Desmond says. Production in recent months has been on the rise. In March, the plant produced the second most energy it ever had in one month. April surpassed those numbers within the first three-quarters of the month. In May, the plant set new energy production records for total output in a single day.
Yet investor interest in CSP has waned. While there are numerous CSP plants operating around the world, there are currently no plans for new sites in the U.S., according to Solar Energy Industries Association.
“It’s a risky business,” says Ed Feo, chief operating officer and managing director of Coronal Group, which invests in and manages renewable energy projects. “That’s how investment in new technology works.”
Still, the technology has its supporters.
“[CSP] has been eclipsed by the rapid decline in price in [photovoltaic] technologies,” says Carl Zichella of the Natural Resource Defense Council. “But I don’t think this industry is done by any stretch.”
He notes that CSP can do something that wind and other forms of renewable energy cannot: easily store power. The super-hot water or salt created from the solar beams can be kept for hours, and released when power is needed. Traditional solar power, by contrast, can only generate electricity when the sun is shinning.
Desmond, from BrightSource, also notes that, as California attempts to ramp up its production of renewables to as much as 50 percent by 2030, the state will need to invest in a variety of technologies, including CSP. “The biggest challenge we face is that policymakers recognize the different values that these different processes have in finding a diversified energy mix,” he says.
This story is part of a special report on energy issues in California produced in collaboration with the University of Southern California's Annenberg School for Communication and Journalism. For more, visit the project's landing page.