IN DEPTH: CPV's time to shine

John Paul Morgan was staring bankruptcy in the face two years ago.

The founder of Toronto-based solar start-up Morgan Solar was weeks away from starting mass production of its innovative Sun Simba concentrating PV (CPV) module at a new factory in San Diego, California. Then the price of silicon fell through the floor.

“Coming into that year we saw the collapsing price of PV and the factory — for which we had a loan from the California Energy Commission [CEC] and in which we had invested millions [of dollars] — and it became clear that there was huge risk that we would launch this project and it wouldn’t be able to compete with falling PV prices and we would simply go bust,” says Morgan.

The management team called an emergency shareholder meeting with its investors, including Spain’s Iberdrola and Canadian energy major Enbridge, and, after repaying the CEC and shuttering the factory, the company’s engineers headed back into the lab to refine their product.

“A lot of companies ploughed ahead with the plans they had written in 2009 and suffered catastrophic financial consequences,” notes Morgan, “but we were in the fortunate position where we weren’t as far down the investment track — and doubly fortunate that we had the support of investors who understood the writing on the wall.”

CPV companies that survived the annus horribilis of 2012 are now poised to be repaid for their tenacity, particularly in the world’s sun-rich regions, where the high-efficiency concentrator-based technology can generate the highest electricity production levels.

International analyst group IHS sees a bull market coming on at a gallop: it predicts that the CPV build-out will mushroom by 750% by the end of the decade, with installed capacity reaching 1.3GW, up from only 160MW last year.

“If we look in the past, only a few megawatts of CPV technology were available through 2010-12 globally, and most of them were test or demo projects,” says IHS solar analyst Karl Melkonyan.

“Only in 2013-14 do we see several commercial projects with 10, 50 or 100MW... this is just a beginning with a high growth potential.”

The key to the anticipated success of CPV will be its cost per MWh over a project’s lifetime, the so-called levelised cost of energy (LCoE).

“Although conventional PV is a more attractive option based on upfront system costs,” says Melkonyan, “this does not take into account the overall cost of the system over its lifetime, nor does it consider the energy yield of the system. It is all in the LCoE.”

The segment’s technology-first ethos is driving CPV systems to superior efficiencies, and making it “an increasingly viable rival” to conventional PV, he explains.

“Recent achievements of Soitec and Semprius in developing four-junction solar cells are very promising in this sector. We believe this will help to achieve efficiencies greater than 50% in the near future [compared to around 18%for conventional PV and 20.4% for thin-flim].

“Efficiency is the most important requirement in CPV technology in order to generate competitive energy costs.”

André-Jacques Auberton-Hervé, chief executive of CPV and semi-conductor outfit Soitec, agrees: “CPV is not just an incremental improvement of the existing PV technology. It is already disruptive in providing a breakthrough in efficiency: 50% is not beyond our reach and we have already achieved nearly 45% from a four-junction cell.”

The star of the Soitec CPV module is the high-efficiency III-V multi-junction cell — descended from space-proven satellite solar panel technology — onto which Fresnel lenses concentrate sunlight 500-fold. Shown in tests at Germany’s Fraunhofer Institute for Solar Energy (ISE) last year to have a 44.7% efficiency, the record-setting cell is fabricated using an output-boosting technique called wafer bonding that makes it possible to efficiently connect two semiconductor crystals.

Soitec’s “innovation and initiative” strategy has led it to wire in 20MW worth of pilot-scale projects in 18 countries around the world as it readies itself for the boom time ahead. This year has been busy, with the sale of the 7MW Desert Green solar farm in California to US developer Invenergy; being chosen to deliver 80% of a French government tender for up to 70MW of ground-mounted CPV; and in March, commissioning of the first half of the breakthrough 44MW Touwsrivier project in South Africa.

“This project makes us one of the first into the African market, and at the same time involved our raising a 1bn-rand [$96.6m] bond, which in its way was also disruptive, a different way of financing a utility-scale solar farm,” says Auberton-Hervé.

Soitec’s pipeline of CPV “opportunities”, as Auberton-Hervé calls them, not wanting to talk up his company’s prospects, nonetheless stands at around 2GW, including a grid-connected 3MW foothold project in western China. However, not everything has gone Soitec’s way — US developer Tenaska Energy recently backed out of plans to install Soitec systems at its CSolar IV project in California, opting for conventional PV instead.

US-based Semprius leapt to the fore last year when it created the first four-junction, four-terminal solar cell, using a proprietary micro transfer technique that prints stackable layers made up thousands of 0.6mm-wide cells onto a reusable substrate. Tested to have efficiencies of 43.9%, the new III-V cell boosts energy yield by capturing light across a broader portion of the solar spectrum.

Last year, the company set a new standard for mass produced lens-based CPV module efficiency, hitting 35.5% in the Fraunhofer ISE test beds with a three-junction-cell-based unit fabricated on its pilot fabrication line at its North Carolina factory.

Within a month, its compatriot CPV rival Amonix hit a module efficiency of 35.9% with a prototype at the National Renewable Energy Laboratory in Colorado.

“We continue to be very bullish about CPV,” says Semprius chief technology officer Scott Burroughs. “It has taken longer than expected — but then it takes time for new technology to gain acceptance, particularly at the utility-scale.”

Semprius, which has 15 small-scale pilot projects dotted around the world, is targeting an LCoE “in the $0.06-0.07/kWh range” off the back of a predicted 200MW annual orderbook.

“That would doubtless change opinions [of the competiveness of CPV],” says Burroughs. “At higher [manufacturing] volumes we expect to be competitive with natural gas.”

“And there is no reason why we can’t develop ever more efficient five-, six-junction cells in the future — 46% is achievable with a four-junction, so 50% is definitely within reach with a six-junction. With a cell this efficient, we would be able to build a 42% efficient module.”

Morgan Solar has bounced back from its near-death experience with plans to unveil this autumn a vastly improved module, which boasts better than 30% efficiency and a manufacturing cost of under $0.30 per watt thanks to a lower-cost, sharper concentrator, a more efficient PV cell and new money from the Kuwaiti Investment Authority (KIA).

The two CPV market leaders, Soitec and China’s Suncore Photovoltaics, are cueing up installations of over 100MW between them in the world’s “high DNI” (direct normal irradiation) regions by the end of this year.

“We perceive that utility-scale projects in areas of high DNI are the future,” says Auberton-Hervé. “And our technologies were made for these environments.”

High DNI parts of the US and Central America are widely seen to the best hunting ground for CPV developers in the short term, with the Middle East, Africa, and China emerging in the coming decade. Being ultra-high-efficiency compared to conventional PV, CPV is seen as having particularly attractive production estimates for the world’s solar resource hot-spots.

According to IHS, installed CPV capacity for the Middle East and Africa (excluding the more advanced market in South Africa) is expected to swell to 155MW in 2017from just 1.8MW in 2012, revved up by Saudi Arabia.

The kingdom’s recent declaration of plans for strategic build-out of 41GW of solar energy generating capacity over the next two decades, underwritten by a capital spend of $109bn, shows how quickly market sands can shift.

Soitec and Australian dish-based CPV outfit Solar Systems have been fast to set up offices in the kingdom, and both have deals to switch on 1MW pilot installations this year.

“The Middle East will doubtless take some time to mature as a major market but it has such an economic imperative — they won’t be doing solar to feel good — because they need to find ways of making electricity without burning oil, and solar is the fastest way to get there, and in gigawatts,” says Morgan, who sees the potential for its investment relationship with the KIA to open doors in the wider Arab region.

Auberton-Hervé notes: “Saudi Arabia is definitely a key CPV sweet-spot and now [the kingdom’s] plans for a very large construction programme of solar power is going to make it a very interesting market for us.”

Much as CPV promises to see stratospheric growth before the decade is out, the idea of it outstripping conventional PV is unlikely, as lower-DNI areas such as Northern Europe, swathes of China and most of North America remain better suited to black-tops.

“Overall, the situation today is very similar to that of the overall PV space in 2007,” says Melkonyan, “beset by high costs and uncertain outlook, but still a positive and good feeling that it will happen.”

Morgan is even more optimistic. “We continue to believe that CPV will be world-changing,” he says, undoubtedly speaking for many in the industry. “We feel reborn.”