Ivanpah, the Glowing Solar Towers Off I-15, Was a Bold Bet That Didn’t Pay Off
Those three blinding towers near the Nevada line are the Ivanpah solar plant, once the future of solar power. Here’s how it works, why it struggled and what it means for California’s clean energy push.
Updated
Update (February 2025): The Ivanpah Solar Electric Generating System, once a milestone in renewable energy, now faces possible closure. Pacific Gas & Electric has agreed to terminate its contracts, citing the higher cost of Ivanpah’s solar-thermal technology compared to photovoltaics. If approved, two of the plant’s three units could shut down by 2026. Southern California Edison is also considering a contract buyout, adding to uncertainty. Environmental concerns, including bird and tortoise deaths from intense solar radiation, have further complicated Ivanpah’s legacy, reflecting the challenges of large-scale clean energy projects.
If you’ve driven between Los Angeles and Las Vegas, you’ve seen it: three towers near the Nevada line, glowing so bright it hurts to look at them, surrounded by 3,500 acres of mirrors. It looks like an alien spaceport. From a plane, it’s even stranger, like three small suns sitting on the desert floor.
That’s the Ivanpah Solar Electric Generating System, one of the largest concentrated solar power plants in the world. When it opened in 2014, it was hailed as the future of solar energy. It hasn’t quite worked out that way.
Ivanpah was the brainchild of BrightSource Energy and Arnold Goldman, a solar thermal pioneer who had earlier been involved with Luz International, which built solar plants in the 1980s before high costs, cheap oil and gas and a lack of government support sank it. By the mid-2000s, things had changed. California’s Renewable Portfolio Standard required utilities to buy more and more clean power, and suddenly big solar projects made sense again.
Ivanpah Solar Power Facility, with 3,500 acres of mirrors in the Mojave. (Erik Olsen)
With money from NRG Energy, Google, and a $1.6 billion loan guarantee from the U.S. Department of Energy, construction started in 2010 and the plant came online in 2014. It could produce 392 megawatts, enough for about 140,000 homes at peak, and it was meant to prove that concentrated solar could work at a huge scale.
Ivanpah doesn’t use the photovoltaic panels you see on rooftops, which turn sunlight straight into electricity. It works more like an old-fashioned power plant with a giant magnifying glass. There are 173,500 computer-controlled mirrors, called heliostats, and each one follows the sun all day, bouncing its light onto a boiler at the top of one of three 450-foot towers.
Photovoltaic solar array in the Mojave Desert in California (Erik Olsen)
Up there, the focused sunlight heats water to more than 1,000°F (537°C), turning it into steam that spins turbines. The problem is that every step, from light to heat to steam to electricity, loses some energy, and some of those losses were bigger than the designers expected.
Plants like Ivanpah convert roughly 15 to 20 percent of the sunlight they catch into electricity. Modern solar panels do 15 to 22 percent, and the best top 25 percent, without all the steam and turbines in between. And panels kept getting cheaper. That doesn’t mean Ivanpah was a waste, but it hasn’t lived up to the early hype.
Ivanpah Solar Power Facility from an airplane. (Erik Olsen)
The problems started early. In its first years, the plant made less electricity than anticipated, thanks to technical glitches, less sunshine than expected and a long learning curve.
It also burns natural gas to warm up its boilers in the morning and on cloudy days, so the turbines are ready when the sun comes up. That led critics to ask how green a solar plant really is if it burns fossil fuel. The amount of gas is small compared to what the plant produces, but it shows the basic weakness of solar thermal: the sun doesn’t shine all the time.
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Then there are the birds. The beams of light reflected toward the towers create a zone of intense heat, called solar flux, that gets hot enough to injure or kill birds that fly through it. Workers call them “streamers,” for the trail of smoke they leave as their feathers burn in midair. (Here’s a video.) A California Energy Commission report described the plant as a “megatrap”: the bright towers attract insects, the insects attract birds, and the birds fly into the beams. Conservation groups have been upset about it for years, and the plant has tested ways to scare birds off.
A burned MacGillivray’s Warbler found at the Ivanpah solar plant during a visit by U.S. Fish and Wildlife Service in October 2013.
U.S. Fish and Wildlife Service/AP Photo
And building something this big wipes out a lot of desert. The Mojave is fragile, and Ivanpah became part of a larger argument about whether clean energy projects belong on undisturbed wild land.
Other countries have built big solar thermal plants too. One of the largest is the Noor Ouarzazate Solar Complex in Morocco. The big difference is that Noor stores heat in molten salt, so it can keep making electricity after the sun goes down, something Ivanpah, which heats water directly, can’t really do.
The Crescent Dunes Solar Energy Project in Nevada, with its 640-foot tower and more than 10,000 mirrors, became a cautionary tale after technical problems shut it down.
(U.S. Department of Energy)
Molten salt isn’t a magic fix, though. Crescent Dunes, just across the line in Nevada, used it too, but leaks in its salt tanks, expensive maintenance and missed targets shut it down in 2019. Its developer, SolarReserve, went bankrupt after its utility customer, NV Energy, sued.
It isn’t completely dead. ACS Cobra, the Spanish company that built it, now runs it at reduced capacity, mostly for evening peak demand, producing far less than originally planned.
Still, storage is solar thermal’s best argument. Heat is easier to store than electricity, and that’s an advantage over plants like Ivanpah that can’t save much for later.
But solar panels plus batteries have gotten so cheap, so fast, that they’ve taken over almost everything, from rooftops to giant solar farms. Some projects now combine the two approaches, like Phase IV of the Mohammed bin Rashid Al Maktoum Solar Park in Dubai.
Photovoltaic solar array in the Mojave Desert in California (Erik Olsen)
So Ivanpah ended up as a giant experiment. It showed what concentrated solar can do and what it can’t, and it got overtaken by cheaper panels and better batteries while it was still new.
Solar thermal probably won’t catch up with panels, but it may still have a role in very sunny places that need to store a lot of energy, and whoever builds the next one will be learning from Ivanpah’s mistakes.
Mohammed bin Rashid Al Maktoum Solar Park (Government of Dubai)
Meanwhile, California’s clean energy buildout has taken off as the state works toward 100 percent clean electricity by 2045. As of 2024, the state had more than 35,000 megawatts of renewable capacity on the grid, 16,000 of it added since 2020. Batteries are the big story, because they cover the evening hours when solar fades. Battery capacity jumped by more than 3,000 megawatts in 2024 alone, to over 13,000 megawatts, a 30 percent increase in six months.
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New projects like the Blythe Solar Power Project, with 485 megawatts of solar panels and 387 megawatts of batteries, power more than 145,000 homes, and help keep the grid up during heat waves.
There’s still a long way to go. California will need about 148,000 more megawatts of clean power by 2045 to hit its goal.
Google arranged the mirrors at Ivanpah to create a tribute to Margaret Hamilton, the pioneering computer scientist who led the software engineering efforts for the Apollo space missions. (Google)
One fun footnote: Ivanpah’s mirrors have also been used as a giant canvas. Google once angled them to make a portrait of Margaret Hamilton, the computer scientist who led the software engineering for the Apollo moon missions, visible from the air.
So next time you’re driving to Vegas and those three towers start glowing on the horizon, now you know what you’re looking at: a bold bet on the sun that got beaten by cheaper panels.
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