Konarka Technologies has announced that the Energy Research Centre of the Netherlands (ECN) has verified that the company’s flexible organic based photovoltaic (PV) solar cells demonstrate outstanding high lifetime after comprehensive environmental testing under accelerated conditions, including high temperature storage and prolonged illumination.

“The environmental testing by ECN further confirms Konarka’s findings,” says Rick Hess, president and CEO at Konarka. “We have been operating PV cells with similar architectures on a roof in Boston, Mass. for more than a year with little or no degradation. Further, contrary to the majority of the research community, claiming that organic solar cells require packaging with either glass or very expensive ‘super barriers,’ we are proud to have demonstrated outstanding high lifetime for flexible cells packaged with commercially available, low cost materials.”

Testing conditions were derived in accordance with the most relevant tests from the Institute of Electrical and Electronics Engineers (IEEE) and the International Engineering Consortium (IEC), and involved high temperature storage in the dark at 65°C, climate chamber test at 65°C combined with 85% relative humidity and illumination under a solar simulator (one sun at 65°C).

The lifetime parameter is defined as greater than 80% of the samples being above 80% of initial performance. Cells surpassed the lifetime requirement after 1,000 hours of testing under a solar simulator (one sun at 65°C), as well as high temperature storage in the dark at 65°C. Cells also exceeded lifetime of 500 hours for the climate chamber test at 65°C, combined with 85% relative humidity.

All solar cells used commercially available, low-cost packaging materials with a water permeation rate in the order of 0.1 g/m2/day and were on flexible substrates.