Solar concentration mirror for PV energy generation. Credit: Replex Plastics.

Yesterday, the DOE announced $27 million in new funding for projects aimed at reducing the non-hardware costs of solar energy – things like streamlining zoning, building codes, regulations, etc. and the IT systems that will support them. It’s part of meeting the Obama administration’s SunShot initiative goal of making solar energy cost-competitive with fossil fuels by 2020, and a pretty strong indicator that DOE and the administration are confident that the hardware side of the technology will be ready.

As with all infrastructure, the taxpaying public will expect the nation’s energy systems to be reliable, affordable, and safe. In the case of solar-generated power, key issues include cell efficiency, producibility, and durability.

Roger French, professor at Case Western Reserve University in Cleveland, Ohio, is leading an effort to look at the long-term durability and lifetime of PV systems and materials. According to a university press release, the recent award of $2.88 million by the Ohio Third Frontier Wright Projects Program, will support the Solar-Degradation and Lifetime Extension Center, for which French will serve as director. Industrial partners for S-DLE include DuPont Photovoltaic Solutions, Underwriters Laboratories, material durability testing experts Q-Lab, micro inverter maker eQED and CdTe thin film company Xunlight26.

S-DLE will have the ability to test PV systems in accelerated weathering conditions and to test the boundaries of extremes in temperature, humidity, freeze-thaw cycles and solar radiation (exposure equivalents of up to 1000 suns). The center will have indoor and outdoor testing facilities for evaluating materials, components, or systems.

The grant builds on another project French is working on with Replex Plastics (Mt. Vernon, Ohio), funded by the Ohio Third Frontier Commission, to develop mirrors and study the lifetime and durability of mirror augmented PV systems.

Some background is provided in the Third Frontier’s pdf of the proposal evaluation for this round of funding. Replex first started developing solar concentration mirrors in 2008. Especially useful in northern regions where clouds can be as plentiful as sunshine, parabolic mirrors can concentrate the solar energy up to 10x. Concentrators can also reduce the amount of silicon needed to generate a Watt of power. When Replex went to market with their solar mirrors, they quickly ran into the “Carissa Plains” problem that made PV system manufacturers unwilling to warrant their products for 20-25 years when solar concentrator mirrors were included.

Back in the 1980s, a PV module array with mirror augmentation located in Carissa Plains, Calif., experienced a 40% loss of power output in just four years, and the mirrors were thought to be the culprit. Follow-up testing pointed to accelerated browning of the ethylene-vinyl acetate as the source of power degradation, probably exacerbated by the high temperatures and concentrated UV light generated by the mirrors. Replex has resolved some of the problems with a mirror that cuts of UV reflectance at 400 nm. An improved understanding of the degradation mechanisms in concentration mirrors and PV modules should lead to improved designs and systems that manufacturers will feel confident about warranting

In previous posts, CTT has been following the activities of 1366 and Emanuel Sachs’ work to improve the manufacturability of silicon for solar cells. Since our latest update in December, the company has announced an additional $8.4 million of funding from GE Energy Financial Services and venture capital firm, VantagePoint, and brings the total raised by the company raised by the company to about $46 million.

Author

Eileen De Guire

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