Time has a great photo essay on the Ivanpah solar thermal power project - The Ivanpah Solar Project: Generating Energy Through Fields of Mirrors.

When I visited the Ivanpah Solar Electric Generating System, which sits in the Mojave Desert on the border between California and Nevada, I had to be careful where I looked. The engineers warned me not to look directly at the receivers arrayed on top of the centralized solar towers, which collected the desert sunlight concentrated by thousands of mirrors on the desert floor. The solar receiver was as bright as the heart of the sun, glowing with a retina-melting white. I had to force myself to look away.

Jamey Stillings, though, has far better eyes than I do. A photographer known for his work capturing mega-scale projects like the new bridge at the Hoover Dam, Stillings has been tracking the construction of Ivanpah since 2010, when he began an aerial survey of the site. His epic black-and-white images of Ivanpah reveal how different this solar plant is from other major infrastructure projects. Unlike solar photovoltaic plants, which generate electricity directly from sunlight, Ivanpah uses hundreds of thousands of curved mirrors to reflect and concentrate the desert sunshine. Three tall solar towers, each ringed by the mirrors, collect the heat and generate steam, which drives electric turbines. When it finally opens later this year, it will be the biggest solar thermal plant in the world.

NPR has a report on the looming completion of the 377 MW Ivanpah solar thermal power project in California - Massive Solar Plant A Stepping Stone For Future Projects.

The largest solar power plant of its kind is about to turn on in California's Mojave Desert.

The Ivanpah Solar Electric Generating System will power about 140,000 homes and will be a boon to the state's renewable energy goals, but it was no slam dunk. Now, California is trying to bring conservationists and energy companies together to create a smoother path for future projects.

To get the best view of the Ivanpah solar project, you have to go up to the top of a 400-foot concrete tower. Below, close to 200,000 mirrors shimmer across a dry, dusty valley. "It's very exciting," says Dave Beaudoin, the construction manager for the $2 billion project located about an hour southwest of Las Vegas. Each mirror is about the size of a garage door, and it's mounted on a pole so it can be pointed at the tower. "We can keep the sun's energy — the rays of the sun — targeted back to the solar tower," Beaudoin says.

All of those mirrors generate about a thousand degrees of heat. It isn't the solar technology most of us think of: dark panels on rooftops. These mirrors heat a giant boiler on top of the tower, where water turns into steam. Beaudoin says that steam powers a turbine that generates electricity.

Greentech Media reports that Brightsource has needed to get some additional funding to complete the plant and is now looking to sell the technology in future rather than build projects - BrightSource Raises Another $35M for Ivanpah and CSP.

BrightSource Energy just collected $15 million of a modest $35 million tranche of venture funding. (It's modest relative to the hundreds of millions the company has raised over the last decade.) ...

Woolard's resignation came on the heels of a BrightSource press release that described the company "evolving from being a U.S. project developer to becoming a global technology provider that also offers development support as well as engineering and operational services." That's tough language to decode, but forgoing project development to become a "technology provider" is reminiscent of a startup's transition to a licensing model -- not always a good sign for a startup. ...

Several months ago, we reported that BrightSource's giant Ivanpah solar thermal project in the Mojave Desert was 92 percent complete. The 377-megawatt project consists of three 459-foot-tall towers encircled by arrays of garage-door-sized heliostats. A total of 173,500 computer-controlled heliostats will eventually reflect the sun onto the receiving towers, heating water to create steam that will drive turbines that produce electricity. Future projects from BrightSource will include thermal energy storage as per Solar Reserve's projects. Another CSP vendor, GlassPoint, directs its steam toward enhanced oil recovery, rather than electrical power. Two BrightSource Energy projects have recently been shelved due to permitting issues. BSE terminated power purchase agreements for the proposed Hidden Hills and Rio Mesa CSP solar power tower projects....

Former CEO Woolard said, "The problem we're trying to solve is [... how to] decarbonize the power supply and maintain system reliability at the lowest total cost to customers." Woolard noted that each picture-window-sized heliostat mirror, installed at the rate of one per minute at the $2.2 billion Ivanpah project, is capable of providing power to approximately one home, without the "hidden integration costs to the consumer" that come with wind and solar.

Since BrightSource was founded, its competition -- natural gas and solar photovoltaics -- has gone through disruptive price drops. CSP has not yet had the opportunity to scale like those two technologies.

Researchers at MIT in the US have stumbled upon a new method to trap light that could lead to a wide variety of applications, not least of all a vast improvement in the efficiency of concentrated solar power generation.

The breakthrough involves what is being described as a kind of “perfect” mirror, which works in a way that deviates from known scientific laws, pitting light waves against light waves, and setting up two waves that have the same wavelength, but exactly opposite phases — where one wave has a peak, the other has a trough — so that the waves cancel each other out. Meanwhile, light of other wavelengths (or colors) can pass through freely.

The Economist has an article on Brightsource's solar thermal power power project(which recently received a US$168 million investment from Google) at Ivanpah in the Mojave desert - Solar Power: Desert Dawn.

IT LOOKS like a planetary tattoo designed to be seen from space, a vast set of concentric circles inscribed in the skin of southern California’s desert. Ground was broken on the Ivanpah power plant, which is to be one of the biggest solar installations in the world, last October. Already, some of the rings of mirrors which will eventually concentrate acres-worth of desert sunshine on to collectors perched atop 140-metre-high towers are in place. And as of this week, so is the financing.

BrightSource, based in Oakland, California, announced on April 11th that it had finalised $1.6 billion in loans for Ivanpah from America’s government. At the same time it announced that Google had taken a $168m stake in the project.

Ivanpah needs all this money because BrightSource’s technology requires it to be vast compared with other types of solar installation. Most solar power comes from photovoltaic cells that turn sunlight directly into electricity: installations of this type can be any size. BrightSource’s system, like other “solar thermal” technologies, concentrates the sun’s heat to drive turbines; and the high-performance steam turbines it relies on are big. The three to be installed at Ivanpah will together have a greater capacity than all the “utility scale” photovoltaic plants yet built in America.

It was once thought that photovoltaic installations might attain a similar size as they spread across America’s West (a prospect viewed with alarm by some environmentalists). There are now indications that this won’t happen. Nathaniel Bullard of Bloomberg New Energy Finance has been looking at photovoltaic projects registered with California ISO, the state’s grid operator, since 2007. Their median size started off close to 100MW; now it is around 20MW. Not all these projects will be completed—but it seems a reasonable assumption that bigger ones may be more likely to fall by the wayside. If so, the average size will drop even more dramatically.

Mr Bullard thinks the photovoltaic business is learning that small, if not exactly beautiful, is easier to get past environmental controls and planning consents, and handier if you want to feed into existing grids. “Brownfield” industrial sites near towns beat desert skies.

This is not to say that big photovoltaic projects are finished. The day after the Department of Energy bestowed its beneficence on Ivanpah, it offered a conditional loan of $1.2 billion to SunPower, a maker of high-efficiency photovoltaic cells, for a 250MW project, the California Valley Solar Ranch near San Luis Obispo. SunPower will build and operate the plant; NRG Solar, a subsidiary of NRG Energy of New Jersey, will own it. (NRG Solar is also investing up to $300m in Ivanpah.)

Such big projects make sense for large solar-cell producers like SunPower and Arizona-based First Solar, since they provide reliable demand with which to keep their manufacturing plants running at peak efficiency. Tom Werner, SunPower’s chief executive, says that although the Solar Ranch project is “on the large side”, there is a role for photovoltaic plants of all sizes, and his company has plenty more of similar scale in the pipeline. As experience grows, he hopes to find banks, rather than governments, to finance them.

Whereas being extremely big remains optional for photovoltaics, for thermal-solar companies such as BrightSource it is a must. BrightSource hopes that in time its technology will prove sufficiently efficient and reliable to overcome the disadvantage of having to raise so much capital. If so, Ivanpah will be the ground on which it makes its case.

TechPulse has a look at some of the operating parameters predicted for the proposed BrightSource solar thermal power plant at Ivanpah in California - Is Ivanpah The World’s Most Efficient Solar Plant?.

BrightSource Energy’s planned Ivanpah plant will be one of the world’s largest solar farms and possibly its most efficient.

When the solar-thermal plant is built on the edge of the Mojave National Preserve (construction is expected to start this year), it will operate at 18 percent efficiency and earn a capacity factor of 30 percent.

This performance should make the 392-MW facility more efficient than plants with crystalline-silicon panels, thin-film cells or rival thermal technologies using parabolic mirrors, according to analysts.

The plant is to be laid out on three nearby tracts covering 3,500 acres of desert and should run at full capacity 10 to 11 hours a day. The company says a back-up natural gas system will aid performance during its long hours of operation, easing power fluctuations on cloudy days. This consistency of power should put electricity costs on par with natural-gas plants, something photovoltaic plants will take another two years to achieve, some analysts say.

While comparing plants is complex and imperfect, the newly available figures from BrightSource make the exercise a useful chore. Sun intensity, atmospheric moisture levels and power transmission costs of course differ plant location to plant location.

But determining who holds the industry’s bragging rights – as well as who deserves project investment dollars – is a task utilities attempt everyday, despite the difficulties.

In an interview, BrightSource Product Manager Andy Taylor described Ivanpah’s efficiency as a sunlight-to-electricity calculation based on two years of testing the company’s Luz Power Tower 550 in Israel’s Negev Desert. At the top of the towers, boilers absorb sunlight reflected from 7-square-meter ground-mounted mirrors and heat water to more than 1,000 degrees Fahrenheit, the highest temperature in the industry. The super-heated steam drives turbines.

The company says a back-up natural gas system permits the long operating hours and the ability to run most of the day at full capacity. The gas is used to warm boilers in the morning and augment solar power on cloudy days to keep output high.

“We’re pretty much a sun-up-to-sun-down resource,” Taylor says.

BrightSource, which has so far raised more than $300 million in financing, expects the plant’s efficiency to rise as the company moves beyond its first-generation technology. Higher-efficiency turbines are already in the market, and additional mirrors, or heliostats, can be deployed. Water temperatures also will rise to above 1,100 degrees.

In contrast to Ivanpah’s 18 percent efficiency, the efficiency of utility-scale crystalline silicon and thin-film plants is likely less than 12 percent. Solar-thermal plants with parabolic mirrors also have difficulties keeping up. Ivanpah’s higher boiler temperatures give it an advantage, and dual-axis tracking can more accurately follow the sun through the seasons. The average efficiency of other solar thermal plants is 13 to 15 percent, says Cara Libby, project manager at the Electric Power Research Institute.

That doesn’t mean Ivanpah won’t have competition, One crystalline-silicon vendor, SunPower, with industry leading 18 percent efficient solar cells, could give BrightSource a run for its money, says Travis Bradford, president of the public-policy think tank, Prometheus Institute. A SunPower farm with a single axis tracking could have an efficiency of 15 percent, maybe slightly higher depending on the location, he says.

Broader competition will come with falling solar-panels prices, unless a stronger Chinese currency slows the trend. Panel prices tumbled about 40 percent last year and, while they are more stable this year, they continue to decline more rapidly than solar thermal efficiency is improving.

BrightSource responds that plant efficiency is only one measure of performance, and not necessarily the best. Capacity factor, a calculation of a farm’s ability to deliver full power over time, may be more important, the company says.

Ivanpah’s capacity factor (including the use of natural gas) should be 30 percent, Taylor claims. A wind farm in an ideal location (think Tehachapi) can have a factor of 40 percent. Photovoltaic plants generally are lower. A Carnegie Mellon Electricity Industry Center study estimates a PV plant in Arizona should be closer to 20 percent.

The NYT reports that the US Government is offering loan guarantees for a large scale solar thermal power project in California - U.S. Offers Solar Project a Crucial Loan Guarantee.

The United States Department of Energy offered a $1.37 billion loan guarantee on Monday to a California company planning to build a large-scale solar power plant in the Southern California desert, The New York Times’s Todd Woody reported.

The loan guarantee for BrightSource Energy of Oakland, Calif., is the largest the department has given for a solar power project. BrightSource’s planned project, the Ivanpah Solar Electric Generating System, is the first utility-scale solar power plant to undergo licensing in California in nearly two decades.

It would use solar thermal technology, in which mirrors concentrate sunlight to heat a fluid and generate steam. If built, it would be the largest of its kind.

“We’re not going to sit on the sidelines while other countries capture the jobs of the future — we’re committed to becoming the global leader in the clean energy economy,” Steven Chu, the energy secretary, said in a statement.

The loan guarantee is contingent on the Ivanpah project passing state and federal environmental reviews. ...

Executives at BrightSource, which is backed by Google, Morgan Stanley, Chevron and BP, have said the loan guarantee is crucial to obtaining financing to build the plant at a time when banks are reluctant to finance new technologies. The company will not disclose the total projected cost of the power plant.

The Ivanpah plant will deploy thousands of mirrors, called heliostats, that focus the sun on three towers that will each contain a boiler filled with water. The focused heat creates steam that drives a turbine to generate electricity. The plant, to be built by Bechtel, is expected to create 1,000 construction jobs.

BrightSource has signed contracts to deliver 2,600 megawatts of electricity to the utilities Pacific Gas and Electric and Southern California Edison.

Chevron Corp.'s emerging technologies unit will build the largest U.S. power plant that uses lenses to focus sunlight onto photovoltaic cells, company officials said yesterday

Chevron Technology Ventures will build the 1 megawatt concentrating photovoltaic power array on the tailing site of Chevron Mining Inc.'s molybdenum mine in Questa, N.M. The project will use lenses --- instead of mirrors, like those employed at solar thermal arrays --- to focus sunlight onto 175 photovoltaic panels. Germany's Concentrix Solar GmbH will provide the concentrating photovoltaic system. ...

The array will be the largest concentrated photovoltaic (CPV) installation in the United States and one of the largest in the world, Chevron Technology Ventures President Des King said. The technology is expected to work best in areas such as New Mexico's desert, which have high direct solar radiation.