Konarka, Dow Target Bigger Roles for Plastics in Solar Power

Flower
Power fueled the 1960s. Now get ready for Plastics Power.

Third-generation
solar technologies use advanced materials, including conductive plastic, to
achieve acceptable efficiencies and design capabilities not possible with
silicon.

Two of the
cornerstone programs in the federal Solar America
Initiative
(SAI) are building-integrated organic photovoltaic technologies
being developed by Konarka, of Lowell,
MA and Dow Chemical of Midland,
MI. Electricity from the grid costs abut 8 cents per kWh now. Power from currently available solar
technology is triple that. The SAI wants its projects to deliver grid power for
less than 10 cents per kWh by 2015.

One novel but pricey application is a sun umbrella fitted with flexible solar panels
that provide electricity on the spot for laptop computers, cell phones or other
consumer applications. They're already being used on outdoor patios of coffee
shops in sunny locations and on patios near swimming pools.

"These
first units are selling for $10,000," says Joe McKenna, executive vice
president of SkyShades of Longwood, FL.
"I hope to drive the price down to $7,500-$8,000 as volume increases;
the first few are always a bit more expensive. Our umbrella units on their own
sell for $5,200 as they are a structure and must be anchored to a suitable
foundation."

The
electricity in the flexible solar panels comes from Power Plastic, a patented
and highly secretive material. A review of Konarka patents shows that much of
its work has focused on conjugated polymers that behave as metallic conductors and
semiconductors. The polymers include at least the following: polythiophenes, polyalkylthiophene,
polydihexylterthiophene (PDHTT), polythienylene vinylenes and polyfluorene
derivatives.

Photovoltaic
cells are produced using continuous web manufacturing techniques in which a
polymeric system is applied in a tree-like geometry to a substrate and subsequently in a roll-to-roll type manufacturing process.
The substrate is any plastic that can be metalized in a web process. One
preferred material is polyester. Other
candidates include polycarbonate, acrylic and polystyrene. Efficiency can be
improved through application of a 
coating that will prevent the reflection of certain types of light. Some
producers also further enhance performance through doping with conductive
materials. The photovoltaic cells can also be applied through other printing systems.

"Konarka's
innovations lie within its materials, manufacturing processes and form factor
for its light-activated power plastic," says Dan Williams, vice president of
business development at Konarka. "We've brought proven coating and printing
know-how from the chemical, photographic film and flexible electronics
industries to energy via a new class of nano-structured materials."

Konarka's
material is two-thirds less expensive than traditional silicon-based solar
materials. It's also very light – only one to two ounces per square foot. Konarka
recently announced a new strategic collaboration with Total, a major oil
company based in Paris.
Total is investing $45 million in Konarka, becoming its biggest shareholder. Total clearly sees some synergies with its
businesses, which include Cook Composites and Polymers, which develops printing
inks as well as other compounds.

The current
demonstrated efficiency of the system is 6 percent â€“ good but not really good
enough. Typical silicon-based solar systems have efficiencies of around 15
percent.

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