RayGen Resources of Australia and the University of New South Wales have built asolarsystem with a world-record efficiency of 40.4 percent. The results were verified at NREL's test facility and handily beat the previous module record of 36.7 percent, which was set in a collaboration between the Fraunhofer Institute and CPV developer Soitec using a four-junction solar cell.

In a release, John Lasich, RayGen CTO, said the company is capable of achieving "close to 45 percent system efficiency in the next few years." John Lasich was a founder of Australia's Solar Systems.

RayGen is helmed by Bob Cart, whom you might recognize as the former CEO of GreenVolts, one of the earlier commercial CPV attempts. The startup had signed a multi-megawatt power-purchase agreement with PG&E in 2008, one of the more sizable CPV projects at the time. But GreenVolts had some troubles and a bit of a boardroom shift: founder Bob Cart was replaced as CEO by JDSU executive David Gudmundson. GreenVolts returned, armed with a new $35 million VC round, which included $20 million from ABB Technology Ventures, the VC arm of ABB. Corporate issues and unprecedented price pressure from Chinese silicon modules prevented GreenVolts from being able to to compete. ABB withdrew its support, and the firm sold off its assets in 2012 after winning more than $100 million in VC funding.

Cart notes that he "left GreenVolts in 2010 to start RayGen," adding that this design is the "next generation" of CPV and it is both capital- and technologically efficient.

RenewEconomy, an Australian energy news website, reported back in 2012 that RayGen collected "$1.6 million in a funding round from private investors, including software entrepreneur Craig Winkler, which will allow it to match grants from the Victorian government and the Australian Solar Institute (totaling $2.75 million)." The report notes that the design combines "high-efficiency solar cells with a low-cost heliostat collector systems" akin to the design of the technology of Australia's Solar Systems, a firm now owned by Silex Systems.

The Australian government's funding documents include a description of the RayGen technology: "The CSPV technology employs an ultra-efficient concentrated photovoltaic (CPV) receiver combined with an optimized heliostat collector field (an array of sun-tracking mirrors). In this system, the heliostats concentrate sunlight onto the photovoltaic cells in the central receiver, which is located at the top of a mast alongside the heliostat field. By using large arrays of inexpensive mirrors, the CSPV technology can sidestep cost issues facing other solar technologies and therefore significantly reduce the cost of large-scale solar energy."

As we've reported, CPV has a 0.25 percent global market share of the 40 gigawatts of PV being installed in 2014. That figure comes courtesy of an optimistic forecast of 100 megawatts installed this year. Proponents tout CPV's benefits as being its low water requirements, low environmental impact, ease of permitting and less degradation. But compared to crystalline silicon, CPV's riskiness in terms of price, reliability and bankability have prevented the technology from achieving commercialization and scale.

Perhaps RayGen will change that with its CPV power tower architecture. The company did not divulge details about the semiconductors, lensing, tracking or cooling used in the design -- nor which device NREL actually tested at its U.S. facility.

Right now, there are three CPV firms developing viable commercial projects: Soitech, SunPower, and Suncore.

Soitec's vertically integrated CPV

The vertically integrated French firm Soitec builds its own multi-junction semiconductor, high-concentration PV systems, and also helps develop and finance its projects. Soitec's technology allows photovoltaic III-V semiconductor layers to bond together with a minimum of lattice-mismatch drama. The firm aims to get to 50 percent chip efficiency within the next few years and to reach module efficiencies approaching 40 percent.

Soitec built the 1.5-megawatt Newberry Solar 1 project in San Bernardino County, California, with power sold to Southern California Edison under a twenty-year PPA. Recently, Soitec christened the 1.3-megawatt Alcoutim CPV plant in Portugal and the 10.8-megawatt Borrego Springs site. Chinese solar project developer Focusic New Energy claims to have a 100-megawatt CPV pipeline, including the 20.5-megawatt Hami CPV power plant using Soitec modules. Soitec has a 44-megawatt project in Touws River, South Africa still in development and approximately 75 megawatts' worth of CPV projects in the ground.

The Touws River project will be the third-largest CPV plant in the world, behind Suncore's 50-megawatt and 60-megawatt CPV plants in Golmud, China.

Soitec just hit a multi-junction cell efficiency record of 46 percent

SunPower's C7 low-concentration tracker in China

SunPower's C7 is a low-concentration (7X), high-efficiency silicon system.

When we last spoke with SunPower CEO Tom Werner, he said that the company was seeing "further traction" with the C7 tracker joint venture in China. Werner said that China is showing "accelerating demand" above the 15 megawatts  of C7 cell receiver packages shipped in Q2 and the more than 115 megawatts of construction backlog, along with a claimed pipeline of approximately 1 gigawatt. Werner noted that while SunPower maintains its IP and ships the high-efficiency silicon receiver assembly, the balance of system (steel, trackers, concrete, etc.) gets sourced and supplied cheaply and appropriately in China, providing some hope for the embattled concentrator technology.

Suncore mixes homegrown technology and acquisitions

Owned by LED chipmaker San'an Optoelectronics, Suncore offers a mix of CPV products and project services. Over the last few years, Suncore acquired the assets of Israel-based ZenithSolar, a combined heat and power CPV vendor, which claimed more than 70 percent combined efficiency. Suncore also acquired the remaining interest in Emcore's CPV business.

Like Soitec and SunPower, Suncore is backed by a large established entity with deep pockets and some patience, two traits necessary to play in CPV.

There are other CPV firms: Arzon is the company that remains after the venture capitalists departed from Amonix. Semprius, REhnu, Morgan Solar, Solar Junction, Banyan Energy, Zytech Solar, Magpower, Ravano Green Power, Cool Earth Solar and a few other startups are still hoping to innovate in the sector and keep up with the price of commodity silicon PV and natural gas. Cogenra's LCPV system is a 14X concentration system using flat mirrors and high-efficiency solar cells mounted on single-axis trackers.