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Harnessing the Sun

Scientists at the UA work to help Tucson become a solar-energy-research powerhouse

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In the bowels of the UA Chemical Sciences Building, a solar-energy revolution is brewing.

Solar research at the UA could soon redefine how Americans power their homes, cars, personal computers and iPods. How? UA chemist Neal Armstrong envisions rooftops, cars and clothing covered with a light, flexible plastic infused with microscopic solar cells.

In the basement of the Chemical Sciences Building, the doors of a large steel service elevator opened to reveal a dim corridor lined with state-of-the-art clean rooms and multi-million-dollar imaging equipment.

"This is where the juicy toys are at," said Armstrong, head of the UA Energy Frontier Research Center. Armstrong opened the door of a small lab that's full of electron microscopes, purchased as part of a $15 million U.S. Department of Energy grant supporting his project.

"Optical microscopes, electron microscopes—and here, we have a real graduate student, by the way," said Armstrong, introducing Gordon McDonald.

McDonald was using an atomic force microscope to determine the precise alignment of tiny light-producing particles. The particles are so tiny—one ten-thousandth the thickness of a human hair—that it would be comparable to a mouse looking up at the Empire State Building. By working on aligning these particles at the microscopic level, Armstrong and his team hope to create a more efficient solar cell.

Armstrong's research center is one of 46 centers nationwide funded by a $777 million grant from the U.S. Department of Energy that was announced in April 2009.

"And life around here has changed forever as a result of that," said Armstrong.

His nearly 40-year career in solar-energy research has been marked by energy concerns that motivated the U.S. government to open its checkbook.

"During the Arab oil embargo from 1971 to 1974, there was a panic. People were lined up at the gas stations," said Armstrong. "We got a directive from the government to go and start looking at research areas looking at energy. So I did that."

He came to the UA in 1978 and was involved in an early version of solar-photovoltaic research, working in a field that uses light-conducting particles to convert sunlight directly into energy.

But the oil embargo would soon be over. The cost of gasoline went down to a quarter per gallon, and funding for solar energy dwindled.

"The money went away, but my interest did not subside," he said.

In 2000, the Bush administration named solar-energy research as one of the "Grand Challenges" to achieve energy sufficiency by the middle part of the 21st century.

"In 2005, it became clear that we were going to have an energy renaissance," said Armstrong. "You can say that my entire career has been building up for what we are doing now."

Armstrong handed over an individual solar cell developed in his lab—a 1-inch-square piece of glass containing a light-conducting liquid material. On top of this sat a thin film, like the coating on the screen of an iPod or laptop.

Armstrong said most of the technology his team uses now didn't exist when he started out 40 years ago. Advances in technology, coupled with a maelstrom of solar legislation and funding, have provided fuel for the furnace of solar research in Southern Arizona.

In fact, Tucson is aiming to become the solar research and production capital of the world, said Congresswoman Gabrielle Giffords at the end of a day-long tour of Tucson's leading solar facilities on April 1.

Armstrong's solar-research effort is one of several projects that could help put Tucson at the forefront of solar power. In another project, UA astronomer Roger Angel, founder of the Steward Observatory Mirror Laboratory, is perfecting the use of mirrors to concentrate sunlight onto an array of highly efficient photovoltaic cells. Concentrating mirrors could lower the production costs of solar panels substantially.

In addition to the research, the Arizona Corporation Commission recently approved two new solar-power systems that will produce enough energy to power more than 6,000 Tucson homes. The package includes a 25 megawatt array northwest of Tucson, and a 5 megawatt concentrating solar power plant at the UA Science and Technology Park. Both are scheduled for completion in January 2012.

"We are at the point where we are taking a big idea and making it into a commercial reality," said Tucson Electric Power CEO Paul Bonavia.

While the gears of solar development are definitely turning, there are still some kinks to be worked out before technology like Armstrong's photovoltaic cells hit the shelves of hardware stores.

"Current solar photovoltaic technology can produce a watt of electricity for between 30 cents to a dollar," said Armstrong. "Our goal is to develop a technology that gets close to the cost of coal, which is 4 cents per watt."

By reducing solar photovoltaic costs, Armstrong hopes to make his technology commercially viable. More importantly, he said, he hopes it will become part of the solution for the world's growing energy needs. By the middle of the century, the amount of energy used by the world's people is projected to double, said Armstrong.

"You guys are going to need every available energy conversion technology to work at peak performance by the middle of the century," said Armstrong, referring to young, college-age Americans. "And you are probably going to want to mitigate global climate change at the same time."

Armstrong said it is theoretically possible for solar energy to displace fossil fuels, but it is highly unlikely. In the meantime, do we have time to sit around and debate the virtues of a solar-powered world? Armstrong said no.

"We have got to get busy. And we have got to get busy on every energy source you guys are going to use," he said.

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