As much as the solar industry pushes to make the world a greener place, the reality is that making solar cells still requires the use of petroleum based-products
BioSolar (OTCBB: BSRC) believes it can change that. The company has developed a protective backing for solar cells that is made from bio-based materials.
When it comes to protecting the backside of traditional, silicon-based cells from the harsh elements of the environment, most manufacturers turn to DuPont for a petroleum-based film called Tedlar.
During a phone interview last week, BioSolar CEO David Lee said his company’s protective backsheet is not only more environmentally sound, but it also will be a cheaper solution once it comes on the market by the end of the year.
That’s quite a promise. But Lee offered few details to back up the claim. He wouldn’t say what materials and processes are involved in making the product, except that it is comprised of two layers made from plant-based materials.
"And they," he said referring to the two layers, "are not coming from a food source."
In recent months, the increased adoption of renewable products such as corn ethanol has come under fire for possibly contributing to rising food prices (see Lester Brown Talks Smack About Ethanol).
Lee plans to unveil the company's technology and discuss what it's made of in August, at SPIE's Solar Energy and Applications conference in San Diego, Calif.
Part of the reason plant-based products haven’t found their way into the components that make up a finished solar system is because of their low melting temperatures and fragile molecular structures, Lee said.
Come rain, snow or unrelenting heat, a solar cell has to be able to handle all that nature can throw at it. At least for as long as the warranty lasts. The solar industry usually slaps a 20- to 25-year average warranty on its panels.
Lee claims that the company's backsheet will hold up for that amount of time. Currently, samples of BioSolar's technology are in the hands of potential customers and industry experts.
James Chaney, president of solar manufacturing consulting firm Arctic Solar Manufacturing, is one of them.
"It doesn't feel like plastic," like Tedlar does, he said. "It feels almost like a thin sheet of cardboard or paper."
Chaney plans to test the product. In one of his experiments, he will heat up the sample to 85 degrees Celsius (185 degrees Fahrenheit) and then freeze it at -40 degrees Celsius (-40 degrees Fahrenheit). He will repeat the same test 200 times.
"It will take me about 40 days to do that," he said. "And if I start seeing deterioration, then we have a problem."
Chaney said he's hoping BioSolar's backsheet will make the grade. He's eager for more renewable solutions for solar manufacturing.
Plus, BioSolar’s entry could help ease the Tedlar shortage that impacts small solar cell makers.
Chaney said some startup cell makers have been known to wait up to six months to get a shipment of the material. Getting Tedlar isn’t so hard for larger solar manufacturers because they usually already have contracts in place.
New companies that want to succeed in the protective coatings business will face a lot of risks, said Tonio Buonassisi, an assistant mechanical engineering professor at MIT.
"You need excellent encapsulation" for solar cells, he said. That's because an acceptable degradation of a cell's performance is around 0.5 percent per year, according to Buonassisi.
If the protective materials fail thus hindering a solar system's performance, companies could find themselves spending a lot of money to make good on warranties, he said.
But despite all that could go wrong, Buonassisi still thinks there are strong incentives for companies to develop better protective back skins.
Solar manufacturers are looking for new options so that they aren't dependent on one company and its delivery timeline.
Some solar manufacturers, like those in thin-film solar, are interested in a higher degree of cell protection.
Thin-film cells, which use little or no silicon, are more sensitive to the elements, such as humidity, than silicon-based ones.
Lee said most thin-film technologies can also use BioSolar's backsheet.
Competing in the same market with a giant like DuPont will no doubt take a lot of money. In total, BioSolar, founded in 2006, has raised about $3 million from a mix of angel investors, friends, family and its public offering in 2007.
Lee said he wants to raise more money to support manufacturing. But he declined to say when and how much.