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Ivanpah: World's Biggest Solar Energy Tower Project Goes Online

Yesterday was the celebration of full operation at the 392-megawatt Ivanpah Solar Electric Generating System, the world’s biggest concentrating solar power tower project. The celebration was attended by technology originator BrightSource Energy (BSE), owner NRG Energy, builder Bechtel, and major equity investor Google.

The application for the project was filed in 2007 and was “just a bold idea,” said Google’s Rick Needham.

DOE Secretary Ernest Moniz was at the celebration and he noted, “Four of the world’s five biggest CSP projects and the first five U.S. utility scale PV projects were supported by DOE loan guarantees,” adding, “As a result, none of the next ten utility scale solar installations required federal support.”

In the face of California’s severe drought, Moniz added, Ivanpah’s dry-cooling technology allows a “parsimonious use of water.”

For Bechtel’s 2,700 employees, Division President Toby Seay said, assembling Ivanpah’s 173,000 heliostats and constructing its three 460-foot tall towers became “this generation’s legacy, its Hoover Dam, its testament to U.S. ingenuity.”

Ivanpah’s integration into California’s grid, BSE Chair/CEO David Ramm said, was performed in planned stages and without unexpected events.

What they did not mention was the giant tent-like facility made from construction materials developed for Iraq that was built at Ivanpah to assemble heliostats. Designed to turn out 500 per day, it turned out 650 twinned, garage-door sized mirrors per day at the height of Ivanpah’s construction.

It is no longer in operation.

The plan was to use the facility to assemble heliostats for the next solar power tower project. But there are no more such projects permitted. NRG plans to use it as a warehouse.

The short term outlook for CSP is a “mixed bag,” reported GTM Research Solar Analyst Cory Honeyman. Two gigawatts of projects with longstanding PPAs are finally coming online, starting with Abengoa‘s Solana Generating Station and the first phase of NextEra’s Genesis solar project. “But the dry spell in new procurement means that installation growth we see over the next two years is rooted in a static pipeline that has been more or less the same since the end of 2012.”


One factor is that, as NRG Energy President Tom Doyle noted, the participation of off-takers Southern California Edison and Pacific Gas & Electric was key. But they and other California utilities have met their near-term renewable energy mandates and are not handing out the power purchase agreements that bring in equity investors like Google.

Demand has shifted to smaller sized projects that can be rapidly deployed in order to meet near term capacity needs, explained Honeyman. “Developers are now bidding into dwindling utility procurement programs at aggressive price points with thin margins that make it increasingly difficult to secure financing.” 

But California and other Southwestern desert states will up their renewables mandates, argued BSE spokesperson Joe Desmond. “Governor Brown said California’s 33 percent mandate is a floor, not a ceiling.”

Another factor is the until-now unproven CSP technology. “Our challenge was to build Ivanpah to demonstrate the technology works at commercial scale,” said Ramm. Investors and policy makers in the U.S. and around the world have been awaiting that proof before committing to it.

A third and crucial factor is the high cost of CSP. Though Ivanpah’s PPA prices are undisclosed, they are thought to be no less than the $0.135 per kilowatt-hour PPA price for SolarReserve’s 110 megawatt Crescent Dunes project in Nevada, far from DOE’s CSP target price of $0.06 per kilowatt-hour.

Through economies of scale, costs can be cut 30 percent to 40 percent, BSE’s Ramm said. BrightSource has said the costs for building Ivanpah’s third tower were significantly lower than for the first.

Between 1981 and 1991, public support allowed developers to build nine parabolic trough projects, CSP Alliance President Tex Wilkins recently recalled. “The first Solar Energy Generating Station (SEGS) cost about $0.24 per kilowatt-hour but the ninth SEGS came in at about $0.12 per kilowatt-hour.”

Both wind and PV were expensive until public support drove market growth and CSP’s price could come down to $0.09 per kilowatt-hour, Wilkins said. “But not until more projects are built.”

Even at $0.09 per kilowatt-hour, CSP will find it difficult to compete in a market place dominated by the still falling PV price and cheap natural gas. One of the keys to getting the cost down and attracting more utility interest will be adding storage capability, Ramm said, and BSE will incorporate molten salt storage into its next project.

The bird-kill sensationalism headlined in a Wall Street Journal is a non-issue, said NRG President David Crane. Only 44 birds were killed by solar radiation at Ivanpah since the project went online in December, he said. Millions are regularly killed by things like urban skyscrapers and house cats. And NRG is involved in intense efforts, in conjunction with state and federal environmental and regulatory agencies, “to take that 44 to 0.”

“The public is convinced there are only a handful of ways to get energy,” said Isaac Slade, lead singer for Grammy winning rock group The Fray, which shot its most recent video at Ivanpah. “But those old school ways do lasting damage and my generation is hip to that.”

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Dustin Mulvaney's picture
Dustin Mulvaney on Feb 15, 2014

Only 44 birds were killed by solar radiation at Ivanpah since the project went online in December, he said. Millions are regularly killed by things like urban skyscrapers and house cats.”

NRG President David Crane needs an avian ecology lesson. When was the last time a cat killed a golden eagle? Not all birds are the same species, and the millions in the cited figure above include very few special status raptors, etc. This skyskrapers and housecats trope should be retired. Being dismissive is unproductive. If we’ve learned anything about the “social gap” in renewable energy, its that all these issues require careful and earnest engagement. 

Nathan Wilson's picture
Nathan Wilson on Feb 15, 2014

CSP will find it difficult to compete in a market place dominated by the still falling PV price and cheap natural gas.”

That’s the real tragedy of the renewable energy movement.  All of the wind power, PV, and even the Ivanpah CSP project are being eagerly installed without energy storage, with the resulting grid problems (such as this Hawaiian example), and the likely fossil fuel lock-in for the other 70%.

California is unique in that it has access to dispatchable/baseload renewable energy resources (desert CSP with storage, geothermal, and part of the Pacific Northwest’s hydro power), which could be combined to produce very high renewable grid penetration (>60%).  It is a shame it does not appreciate baseload, and is wasting money and political capital on wind and PV (which allow only modest targets like 30% renewables).

And this is another bad sign: “ …Ivanpah’s PPA prices are undisclosed…“.

John Miller's picture
John Miller on Feb 16, 2014

Unfortunately, the Ivanpath solar thermal plant is relatively inefficient due to its “parsimonious (low) use of water”.  The dry-cooling technology has been around for 50-100 years and is commonly referred to air or finfan cooling/condensing.  Most conventional power plants that also consist of steam boilers, heated by burning fossil fuels instead of concentrated radiant sun light, normally are built with water cooled condensers and use significant water in the cooling towers/overall energy generation thermal cycles.  However, the use of water allows maximizing the steam-turbine power generation cycle efficiencies, which uses only a fraction of the steam the Ivanpath solar thermal plant does to generate a given level of power-KWh generation.  In other words, if the Ivanpath solar thermal plant steam turbines bottoming cycle was built with a cooling tower and water cooled steam turbine exhaust condensers, the power generation capacity could be directionally double the current design/operating capability.  This would, of course, substantially reduce the cost of power generation of a given solar thermal power plant; perhaps half the power generation cost of the Ivanpath plant.

Installation of a future molten salt heat storage system as referenced in this post is even less efficient than the primary power generation energy cycle of the existing Ivanpath plant.  Yes, such a system will allow the solar thermal unit to generate power when the sun goes down, but at a substantially lower level of efficiency then the Ivanpath plant with air cooling/condensing; i.e. even much higher Btu consumed per KWh generation.

I know this is a lot to technical information, but the bottom line is the Ivanpath solar thermal plant design is generally inefficient and higher cost than the alternative design which uses more water.  Base on the available cost data, solar PV is probably half the cost of this type of renewable power plant.

Paul O's picture
Paul O on Feb 16, 2014

Your point is very well made.

I have learnt to parse the statements made by rnewables advocates very carefully, to discern when they are trying to evade some inconvenient facts or sell something as more beneficial than it actually is.

Rick Engebretson's picture
Rick Engebretson on Feb 16, 2014

Thanks John, you could probably write a lot more on this and it would likely be important in “energy” design discussions.

It seems we consistently equate a watt of electricity with a watt of heating/cooling or transportation energy. Yet our experience shows how different these energy forms are.

Electric power is all about controlled voltage, frequency, and amperage. This control has led to efficient lighting, motors, microwave cooking, computers, etc. When we invite chaos into electric systems, we lose the primary value of this type of energy.

Chemical energy and heat energy have different capabilities. I hesitate to use the words storage and “entropy” but it somewhat applies. These are concepts most of us know and work with as common sense.

How the modern era has so blurred these important energy distinctions politically, to the detriment of energy progress, is hard to understand. I’ve used “concentrated solar” for decades to help heat where I park tractors in a shop. And my one horsepower electric grid average power use helps me try stay sane while listening to classical music. The modern world seems determined to use electric energy to heat the shop, and solar energy to provide classical music.

Nathan Wilson's picture
Nathan Wilson on Feb 16, 2014

John, to be specific, B&W’s brochure describing their upcoming 180 MWatt nuclear reactor claims that its output falls to 155 MWatts (a 14% decrease) when used with air cooling rather than water cooling (but tower CSP plants can use higher temp than LWRs, typically 500C vs 320C, so pay a smaller penalty for suboptimal cooling).  I would guess the air cooled version also has a higher capital cost, so the total increase in levelized cost is likely to be around 20%.  (That’s a fundemental advantage for nuclear, which can be placed in coastal areas near population centers and seawater cooling, unlike desert solar which is generally not near plentiful water.  Air cooling though is important if desert solar is to fulfill its potential to supply a larger chunk of the electricity not just for desert populations, but for the entire world.)

I suppose changing from solar direct steam generation to a design with molten-salt thermal energy storage would also increase the levelized cost, but I would claim that it is worth the increase.  With direct steam generation, the electrical output has similar variation as tracking PV, which as you mention is lower cost.  The addition of storage triples the capacity value of the plant, since unlike power from PV, it doesn’t turn-off just when people are getting home from work to power-up their kitchens, TVs, lights, air conditioners, and EV chargers.

In short, energy storage is necessary to make solar power useful in a grid that is not dominated by fossil fuels.

John Miller's picture
John Miller on Feb 17, 2014

Nathan, if you are familiar with steam-thermal Rankine cycle I am sure you are aware of the many variables that must be optimized to maximize power generation efficiency.  The efficiency of the solar thermal power generation is a function of the supply (generated) steam temperature and pressure, steam turbine design/efficiency, and the turbine’s exhaust temperature-pressure.  Modern (higher efficiency) fossil fuel fired and nuclear boilers typically operate a 1000+ psig and 300+ degree C (super heated steam) and the steam turbines’ exhausts operate under vacuum (water cooled condensers).  If indeed the solar thermal super heats the steam by a couple hundred degrees C, this helps off-set some of the lower efficiency (higher pressure-temperature) of the turbine exhaust air cooled condenser operation.  Despite these directional improvements, the levelized costs of solar thermal are still the highest of all available sources of power generation; over double nuclear and almost double solar PV.

Agreed, power storage is necessary to feasibly displace intermediate/peaking natural gas power.   The largest challenge continues to be the huge cost disadvantage of current-developing energy storage systems (excluding hydropower pumped storage) vs. incremental natural gas power generation.

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