The University of Arizona Tech Park capped off the first phase of its massive solar-energy test yard Wednesday with the dedication of a 1.1-megawatt concentrating photovoltaic system built by California-based Cogenra Solar.
UA officials also announced an expansion of the Solar Zone — which now provides enough solar power for more than 3,200 homes — in a second phase still in the planning stages.
The system inaugurated Wednesday, which will supply Tucson Electric Power Co., is the UA test site’s first trough-type concentrating PV system. It also is the biggest and first utility-scale project for Cogenra, which has installed about 40 commercial-scale systems.
“I think for many years there will be more projects like this, but this is a turning point,” Cogenra CEO Gilad Almogy said, noting that the Mountain View, California, company’s aim is to make its technology cost-competitive with fossil fuels.
“It’s a big step to make it so people do renewable (energy) not because it’s renewable, but because it’s the lowest-cost solution.”
Almogy noted that his company recently set world records for three types of silicon-based PV modules, using a patent-pending design to eliminate much of the wiring that ties individual PV cells into larger modules or panels. The company makes its own multi-cell modules in California from commercially available PV cells.
Cogenra’s “dense cell interconnect” design — which eliminates power loss between cells — was so successful that the company is now marketing standard-size flat PV modules for use without concentrators, he said.
The project’s owner is Washington Gas Energy Services, which will sell the energy for an undisclosed price to TEP under a 20-year contract. TEP is adding solar generation to meet a mandate that state-regulated power companies increase the share of renewable energy to 15 percent of their retail sales by 2025.
“This is by far the most unique setting I’ve seen in the country,” Nate Greenberg, Washington Gas Energy senior account manager for solar, said of the Solar Zone. “It was really a no-brainer for us.”
Cogenra’s T-14 concentrating PV array features long, parabolic troughs of mirror-glass strips that focus sunlight on monocrystalline silicon photovoltaic cells — which convert light directly into electricity — mounted on a bar above the troughs. The troughs are set on motorized pivots that track the sun’s movement from east to west, to maximize light collection.
The Cogenra system also can be configured to capture and use heat. Though the test-yard installation is only set up for photovoltaic generation, a smaller setup installed last year provides power and hot water to one of the Tech Park’s office buildings.
TEP is buying the power from all of the Solar Zone installations at varying costs under power purchase agreements. The Cogenra system will provide enough power for about 96 homes.
The cost of such agreements generally is kept confidential. Almogy declined to divulge the cost of the Solar Zone project, which qualifies for a 30 percent federal investment tax credit.
With the installed cost of PV generation running at just over $2 per watt according to industry and government estimates, Almogy said the company is working toward a goal of $1 per installed watt.
TEP officials said last year the utility’s cost for power from renewable-energy purchase projects had ranged from about 10 cents to 14 cents per kilowatt hour.
Last week, Cogenra was awarded a $2 million grant through the Department of Energy’s SunShot program to build a solar-module plant in the U.S. The company says the UA Tech Park installation my reach the SunShot program goal of generating power for 5 cents per kilowatt hour.
With the first phase in place, the Solar Zone boasts 22 megawatts of solar power generating capacity featuring a mix of solar technologies over eight installations on 165 acres.
Bruce Wright, UA associate vice president for tech parks, announced Wednesday that in the project’s second phase, 29 acres will be added to the Solar Zone and research will branch out into renewable-energy storage and related systems. While UA students already benefit from cutting-edge research at the test zone, a public educational component will be added with a planned information and visitors’ center, still in design.
The Cogenra system is the second concentrating photovoltaic system installed at the Solar Zone, along with a 2MW system made by Amonix that uses a dual-axis tracking system and special lenses to focus sunlight on high-efficiency PV cells.
Groundwork for another concentrating PV system — under development by Tucson-based startup REhnu Solar — has been laid but the company put off installing its optics-based solar system as it developed new generations of the system.
REhnu, founded by UA optical scientist and regents’ professor Roger Angel, plans to install an 840-kilowatt dual-axis tracking system with the latest third-generation design in the near future, said Thomas Stalcup, the company’s chief engineer.