Solar Curtain Wall by Konarka

arch article Solar Curtain Wall by Konarka

Konarka Technologies and Arch Aluminum & Glassplan to erect two walls of solar panels in a pilot project to gatherdata for architects and other customers interested in integrating solarcells into building materials.

Glass panels encased with Konarka’s organic solar cells will go upagainst the south- and east-facing walls of an existing Arch officebuilding in Tamarac, Fla., by the end of the year, Konarka saidTuesday. Each solar panel will have a peak power output of 48 watts,and the entire setup with will have 1.5 kilowatts of generationcapacity.

For the pilot project, the solar panels are set alongside thebuilding. But for the commercial products that Konarka and Arch want todevelop, the solar panels would become the "curtain walls," or building façade, said Terri Jordan, vice president of business development at Lowell, Mass.-based Konarka.

"This pilot installation will be used as a living laboratory,"Jordan said. "We will be doing analysis on the levelized cost of energyto ensure that this will have a reasonable payback for customers."

In May this year, Konarka and Arch announced a product developmentplan to tackle the so-called "building integrated photovoltaic" (BIPV)market. The BIPV market is new, and skeptics abound.

Proponents say BIPV is a vast and untapped market, and embeddingsolar cells into materials and components for building construction isa logical extension of putting solar panels on rooftops.

Critics say the added costs of integrating solar cells andinstalling the solar panels and other electronic devices and wiresnecessary for electricity generation make the whole BIPV conceptunfeasible. At least for now. 

There also are costs and hassles with maintaining and replacing allthese electrical equipment, which are likely to have a much shorterlifespan than the building itself.

The BIPV market opens up new opportunities for Konarka, which wasfounded in 2001 and struggled in early days to develop marketablecommercial products. It has attracted more than $150 million in privateinvestments and $20 million in government research grants sinceinception (see Konarka Gets $45M From Total).

The company began mass production of its Power Plastic films inOctober 2008 at a factory in New Bedford, Mass. Konarka has sinceannounced sales agreements with makers of portable electronics andconsumer products embedded with its solar cells, such as shoulder bags and café umbrellas.

Konarka develops organic solar films that use a polymer forconverting light into electricity. The polymer is typically printedonto different types of flexible materials. Jordan declined to disclosethe make-up of the polymer.

The limited efficiencies of organic solar cells make them lessattractive to the conventional solar energy equipment market. Most ofthe solar panels today are made with silicon while some use alternativesemiconductors to convert sunlight into electricity.

The most efficient silicon solar cell can convert 22 percent of thesunlight into electricity. Some other materials could reach more than10 percent efficiencies.

Konarka has produced cells in its lab that could get to 6.4 percent.Lab results tend to be higher than what can be achieved in commercialproduction. Panels of Konarka’s Power Plastic material has about 3percent efficiency, Jordan said.

That 3 percent efficiency is what the company has achieved with itsopaque red Power Plastic films, she added. The green version, whichKonarka plans to roll out in January, should be able to get to 4percent to 5 percent panel efficiency, Jordan said.

The company also plans to make these colorful films transparent nextyear. The company’s researchers developed the transparent films onlythis year, and part of the development pact with Arch calls for Konarkato improve the performance of the transparent films, Jordan said.

Some architects prefer the glass façade to be transparent foraesthetic reasons, though the transparent films tend to have lowerefficiencies, Jordan said. The company has surveyed architects abouttheir color preferences.

"The architects we’ve spoken to in Europe and the U.S. tend to likethe gray because it’s neutral and the green because it’s suggestive ofgreen designs," Jordan said.

Konarka and Arch will experiment with panels with opaque andtransparent films, as well as with different colors in their pilotproject. Arch also will experiment with different glass designs.

Jordan declined to discuss manufacturing and installation costs,saying that the pilot project would provide the necessary data todetermine those numbers. 

archbefore Solar Curtain Wall by Konarka

The "before" image of the solar curtain wall.

archafter Solar Curtain Wall by Konarka

A rendering of what the solar curtain wall will look like once installed.