Ivanpah connects to the grid

The 377 MW Ivanpah Solar Electric Generating System is now close to completion in California. Eighteen times the size of the largest CSP tower project online –Torresol’s 20 MW Gemasolar - the huge project has overcome enormous hurdles to be on track for completion on time.

By Susan Kraemer

“Ivanpah Solar Electric Generating Station is a crucial milestone on the road to achieving a clean energy economy and an engineering marvel devised and built by American workers and their unions with financial and other support from the federal government,” says Jeff Holland, speaking for NRG Energy, one of the project’s joint owners with BrightSource and Google.
The gigantic project met a very thrilling milestone on time at the end of September. "The first unit was synced to the grid,” says BrightSource spokesman Jared Blanton. “That doesn’t mean it’s in full operation, but just the first amount of electricity was sent to the grid.”

Unlike Rio Mesa and Hidden Hills, BrightSource’s two other giant CSP projects that failed to make it through the permitting process, Ivanpah has been meeting all the milestones it needed to along the way in order to remain viable. Both its Loan Guarantee and its PPAs are subject to certain milestones being met on time.

At this point, it is almost complete, with startup expected at the end of the year.

PG&E had signed a 25 year PPA in 2009 for the full output of the first and the third units, beginning in 2013. SCE is the off-taker for the second unit. Under these PPAs BrightSource promises to deliver a pre-agreed amount of electricity generation, measured in annual gigawatt-hours of power.

PPAs signed for gigawatt-hours of solar

“The gross is 392 and net is 377 MW," says Blanton. "But when we sign a PPA, we sign it in a certain number of gigawatt-hours of production.”

To supply the PG&E PPA from units 1 and 3, Ivanpah’s expected production is 640 gigawatt hours annually, according to the PG&E contract amended in 2010 (after some changes were made to meet environmental permitting requirements). Unit 2 supplies customers in the SCE ratepayer district.

All three units at Ivanpah will supply 100% of the electricity needed to run 140,000 homes until 2039, under PPAs for 25 years, and likely for much longer. According to SolarReserve CEO Kevin Smith, it is likely that CSP plants could run indefinitely with good maintenance.

BrightSource predecessor Luz built the oldest CSP project in the world, the old 1980s SEGS project in California, which recently completed its first 25 year PPA. As the first of its kind, its first contract was much more expensive. But the new PPA, on the now paid-for plant, is now averaging under 6 cents a kilowatt hour, according to Mark Ulrich at SCE, the off-taker.

This is the cost trajectory that the US Department of Energy SunShot Initiative is hoping to generate - for new plants. Its mission is getting the cost of CSP down to 6 cents a kilowatt hour by 2020. (The 6 cents is figured in levelled cost of energy (LCOE) amortised over the several decades that the plant needs to operate.)

When the SunShot program was planned in 2010, CSP was 21 cents a kilowatt hour without subsidies. Now, SunShot Initiative CSP Director Dr. Pitchumani tells CSP Today, they are getting reports of prices of as low as 13 cents a kilowatt hour.

Unlike the oversupply situation that has decimated PV prices, this is real cost reduction, and not the result of desperate surplus inventory unloading. Another DOE program had much of the credit for this, the Loan Guarantee Program (LGP).

Fruit of the Loan Guarantee Program

BrightSource’s Ivanpah was among several gigantic new CSP projects in the US to receive a loan guarantee through the DOE, back when the Democrats held the purse strings in congress. The idea was to jump start the renewable sector in the US, reducing investor risk by guaranteeing loan repayment, and applicants themselves paid into a fund to insure payouts.

“The first time when somebody ever does something, there’s a tremendous amount of risk,” says Minh Le, Director of the SunShot Initiative. “Like Christopher Columbus, the first time he sailed to the New World: people thought he’d fall off the edge of the world.”

“But once risk has been reduced, in a new tech like CSP, over time the business communities will take over,” he adds. “The DOE Loan Guarantee has taken out some of the risk in the very first large scale projects and that will help enable costs come down.”

Due to political differences within the US congress, the LGP has been ended for renewable energy, shifting away for now to fund nuclear and fossil energy under a Republican congress.

But the DOE’s solar SunShot program has continued on (albeit with a fraction of the LGP budget) and is shifting the focus from reducing financing costs, to reducing construction costs.

SunShot reducing construction costs

“What you’re seeing now is a shift in strategy towards trying to develop a technique to lower cost, because that cost is ultimately what matters,” says Le, who believes that this is really what’s going to enable CSP to scale rapidly.

“There’s some amazing advantages on the technology side,” says Le. “The mirror field represents on the order of 40 to 50 percent of the cost of the project. BrightSource, for example had something like 170,000 mirrors out in the field, each with motors that have to control the mirror very precisely. That represents roughly half the cost of a large scale system. Back in 2010 when we were planning the SunShot Initiative, each of those mirror collectors used to cost around $200 a meter square.”

At this point, SunShot has this cost down to $135 a metre square. The goal is to reduce it even further, to less than $75. Multiplied by 170,000 (for 377 MW) heliostat assembly adds up to big money pretty fast, and so it is precisely this modular aspect of the solar field that lends itself the most to the cost reductions that come from old fashioned assembly line efficiency.

“There’s a number of people working on lowering the costs of the solar field,” says Pitchumani. “Our goal is $70 - $75 a meter square, and to have lightweight structures with fewer assembly requirements, so that you drive down the cost of the structure while still being able to endure the harsh conditions that they withstand in the field.”

Ivanpah onsite mass production

At Ivanpah, BrightSource has sped up the mass production assembly of the 170,000 heliostats in an 48,000 square foot facility onsite, using automated machinery and a conveyor system. Once assembled, these are installed by crane onto the steel pylons.

At peak, this facility is now assembling 500 heliostats a day. The firm was was awarded SunShot funding to develop and demonstrate the facility, to help get CSP costs down by speeding up manufacturing, assembly and installation practices onsite.

“To build a 250 mw plant and a solar field for that, takes about two years or so,” says Pitchumani. “Our challenge that we are presenting to the industry is can they get it down on the order of three to six months.”

The SunShot Initiative hopes to cram into a short period of time the sort of mass production experience that the PV industry gained over decades. “What we do know,” concludes Dr. Pitchumani, “is that there is a learning curve for initial deployment that will translate to cost savings on future projects.”

To comment on this article write to Susan Kraemer,
Or contact the editor, Jennifer Muirhead.