With a major shakeout still ongoing in the solar-energy industry, new sun-harvesting technologies are dying on the vine - perhaps deservedly so, in some cases.

But homegrown solar technology pioneered at the University of Arizona recently got a big vote of confidence from Uncle Sam.

REhnu Inc., a company co-founded by famed UA astronomy professor Roger Angel, recently was awarded $1 million by the U.S. Department of Energy to help commercialize its proprietary concentrating photovoltaic (CPV) technology.

The grant was awarded through the DOE's SunShot Initiative, which aims to boost solar technology startups. Under terms of the grant, REhnu will spend about $1.5 million of its own capital, for a total project cost of $2.5 million.

The award was notable on several levels, REhnu CEO Justin Elliott said.

REhnu was one of just 10 companies to receive SunShot awards and the only recipient specializing in concentrating PV technology, which involves concentrating the sun's rays onto photovoltaic cells.

"This was an intensely competitive process," said Elliott, adding that though the number of applicants wasn't released, it is believed to be in the hundreds.

Under terms of the DOE award, he said, the company won't get any money upfront but instead will apply for reimbursement as it reaches specific milestones.

Elliott said the company will use the money to drive toward a low-cost, mass-producible product.

REhnu already has cut more costs and eked more power out of Angel's original design, which concentrates sunlight through a spherical lens onto high-efficiency photovoltaic cells, said Elliott, who joined REhnu in January as chief operating officer.

"We're really pleased that we came through as the only representative of CPV," Elliott said. "A large number of CPV players have gone by the wayside because the technology was too complex or the component cost was too high."

Those CPV failures include last year's much-publicized bankruptcy of Solyndra, which received $535 million in federal loan guarantees. More recently, Silicon Valley-based SolFocus shut down operations and is seeking a buyer, and California-based Amonix - which has a demonstration array at the UA Science and Technology Park - shut down its year-old Nevada factory last summer.

Against that backdrop, REhnu's renewed mission is to get manufacturing costs as low as possible.

The original design involved a large cooling box and a lightweight, yet rigid space frame to house mirror arrays.

The new design, Elliott says, uses just one square, parabolic mirror per light receiver, instead of four, and the cooling radiator unit has been streamlined to reduce weight and shading on the mirrors. The latest design allows the cooling apparatus to be moved to the pedestal of each unit, Elliott said.

The lighter design eliminates the need for a complex space frame - a design borrowed from telescopes - and allows the use of sun-tracking mounts currently being mass-produced, Elliott said.

"What we're trying to do with the technology that Roger and his team came up with is to keep its core functionality but in a form that allows us to make much more use of existing factories and manufacturing equipment," he said.

The design also makes it possible, and economical, to change out the system's high-efficiency, triple-junction PV cells - which now offer twice the energy-conversion efficiency of standard rooftop PV cells - to even more efficient versions as they become available, Elliott said.

For example, he said, after 10 years PV cells with a nominal efficiency of 40 percent could be swapped out with cells offering 50 percent efficiency.

Unlike standard PV panels, which degrade over a lifespan typically pegged at 25 years, REhnu's robust and rebuildable design could last upwards of 40 years, commensurately driving down per-watt costs, Elliott said.

But much work remains to be done.

REhnu built a foundation for a prototype solar-power unit at the UA Tech Park's Solar Zone demonstration site, but the working prototype has remained on the main UA campus in the old pool behind Bear Down Gym.

The company will move the prototype to the tech park site in the coming months, Elliott said.

REhnu, which raised about $1 million in an initial venture-capital funding round in January, is looking to raise $8 million in its next round, Elliott said.

Helping seed companies for further private investment is a major goal of the DOE, which has awarded more than $92 million through the SunShot incubator program since 2007.

The DOE says those investments have attracted nearly $1.7 billion in follow-on private investment.

Contact Assistant Business Editor David Wichner at dwichner@azstarnet.com or 573-4181.