Photovoltaic Glass Stands Up to 'Wall of Wind'

Photovoltaic Glass Stands Up to 'Wall of Wind'

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July 2010

Set-up of the module testing at Florida International University’s Wall of Wind facility. Using an elevated ramp to maximize wind stress, six 500-horsepower driven fans generated top wind speeds of 115 mph (185 kph).

Corning technician Shaun Congdon prepares for data collection prior to testing. Multiple sensors fed data to the team’s computer for further analysis.

Corning’s Jim Webb (left) inspects the module after testing with Girma Bitsuamlak of Florida International University, and Corning’s Kevin Wasson in front of the Wall of Wind fans.

The Wall of Wind generates hurricane force winds through a series of 6 – 502 horse power “Chevy Big Block” racing engines connected to fan boat propellers.

Corning’s thin-film photovoltaic (PV) glass is barely thicker than a dime, but it recently proved its ability to withstand hurricane-force winds in a full-scale field test at Florida International University’s Wall of Wind facility. The testing yielded data that makes an important point to customers considering Corning’s PV glass for manufacture of thin-film solar modules: Corning’s PV glass can endure some of nature’s harshest conditions, making it well suited for large-scale solar installations that need to last for 25 to 30 years.

Florida International University’s research facility is typically used to test roofing and other architectural materials. The team mounted an array of modules built with Corning’s fusion-formed PV glass in a specially built aluminum frame tilted to a 40-degree angle – the pitch that would take the most brutal force of an oncoming wind in a real solar field setting.

The thin-film module withstood great wind stresses, resisting breakage through sustained winds of 81 mph (130 kph) and gusts up to 115 mph (185 kph).

Strain gauges, strategically located on the glass, measured the wind stresses from a variety of speeds and angles, while force transducers measured wind loads on the entire module. Dust and small pieces of debris from the surrounding fields were caught up in the wind and hit the glass as well. “It vibrated in the turbulent environment – you could see it shake – but the glass never broke,” said Dr. Kevin Wasson, senior Corning project engineer on the team. “It was very impressive.”

Dr. Jim Webb, who leads the Corning PV Reliability & Mechanics Team, said data collected in Florida builds on the research already done in Corning's own PV reliability lab at the company’s Sullivan Park Research facility.

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“We have many tools available to us internally to ensure the reliability of thin glass for PV applications,” Webb said. “We do hail testing. We have equipment to apply uniform pressure on the glass, comparable to that of a heavy snowfall.  However, it’s very useful to conduct testing at a facility such as the FIU Wall of Wind, which simulates real-life conditions.”

“We now have an immense amount of data that validates our confidence in this product’s reliability,” said Dr. Mark Krol, commercial technology director. “This is a milestone in challenging the misconception of fragility when it comes to thin glass.”
 
Reliability is not the only factor considered when customers are evaluating thin glass for PV modules. Conversion efficiency – the rate at which the module converts sunlight into electricity – is also a key consideration. “Corning has already demonstrated increased conversion efficiency vs. soda-lime glass at selected customers,” said Krol.
 
“The test brings us closer to market by demonstrating that thin glass is reliable and suitable for PV applications,” said Commercial Director John Duke.

“Our customers certainly appreciate the depth of testing that we’re conducting,” added Duke. “We’re not just looking at basic qualifications to meet PV industry standards.  We now have confidence that our thin glass can withstand significant, sustained stress, which is exactly what our customers expect, as we move forward with commercialization of a specialty glass ideally suited for photovoltaic applications.”

Note:  The analyses and conclusions contained herein are solely those of Corning and not those of Florida International University (FIU).  FIU makes no endorsement of any kind of any product nor does FIU express an opinion as to the accuracy of Corning's analyses or conclusions.