By Alan Fischer
TNAZ Senior Writer

Tucson, AZ. It's hard not to notice a solar company whose motto is, "Don't leave the planet to the stupid."

But SOLON Corp. is firmly backing up its somewhat provocative "green" statement with research and results.

The Arizona company is working to improve efficiency of photovoltaic solar cells – and the large-scale solar facilities in which they are used – with less expensive electricity produced from the eco-friendly power of the sun.

Tucson-based SOLON Corp., a subsidiary of German solar giant SOLON SE, manufactures solar modules that are used in utility and municipal solar fields, small businesses and residential applications, said Olaf Koester, CEO.

The company, which provides turnkey solar operations to municipalities, utilities and school districts, is also working to improve efficiencies through better design and execution of large-scale solar plants, Koester said.

"You can really screw up if you have a bad design of a solar field. You are losing up to 25 percent efficiency if you are not doing a good design of the field, using the wrong diameter cables, not using a good design of the (solar module) strings, using the wrong inverter," Koester said. "There are a lot of specifications you can improve to design a better power field.'

SOLON engineers are studying solar field design with the goal of reducing the efficiency loss from 25 percent to 15 percent or less for large-scale solar facilities, he said.

The company is also working on improving solar cell technology, he said. While SOLON Corp. does not produce the solar cells it uses to manufacture modules, it works with suppliers and potential suppliers to improve the quality and efficiency of the material.

"We have stakes in four or five different cells companies and the reason is helping the companies deliver, produce and design the right product – and for getting future deliveries," Koester said.

One such partner is Global Solar Energy Inc., a Tucson company that designs and manufactures thin-film, flexible solar material called CIGS, for the Copper Indium Gallium diSelenide from which it is made.

SOLON SE has a 19 percent ownership stake in Global Solar, and SOLON Corp. uses the CIGS material in about 10 percent of the modules it manufactures. "It is going up because Global Solar is improving the efficiency. The idea is to have 50 percent silicon and 50 percent thin film," he said.

The company has set up a testing site at Tucson Electric Power Co.'s Irvington Road campus, where different solar cell designs and array configurations are tested under Arizona sun and weather conditions.

"Its really testing every new technology, one-axis tracking, dual-axis tracking, solar concentrating systems: everything that could be the next product we will be bringing to market," Koester said.

TEP and its customers benefit several ways, said utility spokesman Joe Salkowski.

SOLON shares with TEP information on solar cell performance, he said. "We are finding which technology works best in our climate and the specific installations that are popular among our customers and it will be helpful to us to understand the characteristics of these technologies from a systems design characteristic," Salkowski said.

The power produced by the solar test site also goes into TEP's grid system, reducing slightly the amount of coal and natural gas burned to produce the power needed by the utility's customers, Salkowski said.

SOLON is also involved in trying to reduce the cost of silicon, upon which solar cells are widely based.

Reducing the cost of silicon is crucial in order to approach cost parity between solar and fossil fuel energy production methods, Koester said.

SOLON's modules can produce electricity for about 15 cents per kilowatt-hour, compared to about 9.5 cents per kilowatt-hour for power purchased from TEP, Koester said. Any increases in electric rates will make solar even more cost effective, he said.

SOLON is working with Solar Technology Research Corp., a Tucson company formed to use technology developed at the University of Arizona to produce solar-grade silicon at significantly reduced costs.

"STRC is perfecting a process to inexpensively purify metallurgical silicon for photovoltaics," said Jeff Baymor, chief financial officer at STRC.

SOLON invested in STRC, and the company is located in SOLON's building at 6950 S. Country Club Road.

Solar silicon need not be as clean, or expensive, as the material used by the semiconductor industry, Koester said.

He expects developments by STRC to drop silicon pricing from the current level of $70 to $80 per kilogram down to $20 per kilogram if the firm's technology proves successful.

The company is also looking at storage devices, since solar panels do not work at night, or work as effectively during cloudy conditions, Koester said.

While most power is used during daylight hours, large cities like Phoenix are seeing peak energy usage continue into the evening. This is due to increased use of air conditioning because heat sinks like concrete and asphalt keep temperatures high long into the night, Koester said.

SOLON has about 140,000 square feet of manufacturing, warehouse and administrative space, recently adding 30,000 square feet. The company uses highly automated production methods, said Jon Sams, manager of administration.

The firm employs about 125, with 75 percent in production with the remainder working in engineering, finance, administration and marketing. Plans call for going from two eight-hour shifts to three next year.

The company receives components from around the world, including solar cells from 10 different providers offering varying technologies.

Production equipment used at the plant comes from Switzerland and German, Sams said.

The manufacturing process begins with washing and inspecting the low-iron tempered white glass used in SOLON's modules that protects the delicate cells in the field.

"If you take the cells outside the lifetime of a cell would be one day or one hour. It's like a potato chip: very, very thin, very, very fragile," Koester said. "What we are doing is protecting the cells in a safe environment, encapsulated in safety glass. Only this way can you use the module for 25, 30 years or longer."

A Team Technik TT900 Stringer robotically laser solders solar cells, each 6 inches by 6 inches, into long strings linked with connective wiring.

The human touch is needed at the manual lay-up station, where skilled workers solder the cell strings into final series parallel configuration. Currently there is no machine that can do the job as well as humans.

Modules typically contain 60 or 72 solar cells, and weigh from 52 to 66 pounds respectively, ready to go.

The product next goes to a 3S Laminator, where the solar cells and protective tempered glass are encapsulated in EVA laminate material. It takes about 12 to 15 minutes for the laminate material to cure.

The Reis Robotics Framing Station features four huge orange robotic arms that build an aluminum frame around the laminated panels to protect the edges and make it easier to handle and mount the final solar module.

Junction boxes are added to the framed modules.

The completed module is than tested in a Berger Lichttechnik Flashing Station, where a bright light is flashed on each panel to determine how much power each will produce while eliminating modules with problems.

Several factors led to SOLON Corp. selecting Tucson as the site for a facility that serves North America, South America, Korea and Australia.

"Arizona is really in the center of the solar market," Koester said. "California is still the biggest market, but you have perfect connections going in every direction. The thought was to get logistics costs low and be very responsive with deliveries to customers.

Close proximity to solar cell provider Global Solar Energy, in which SOLON SE owns a stake, also played into the decision, he said. Low local labor costs were also attractive, Koester said.

Koester sees the area ripe for further expansion: "I'd like to see Tucson as a growing solar industry. It is the prefect place to do this. You have a market here, good location, and you can produce here."

SOLON Corp. is currently building a 1-megawatt turnkey solar installation that will be used to power a Pima County wastewater treatment plant, Koester said. The facility, slated for completion in late November, will be made up of about 4,000 solar modules, all of which come from SOLON in Tucson, he said.