Solar Power’s 50pc drop in cost underscores urgent need for greener production methods

SANTA CLARITA, USA: Dr. David Lee, CEO of BioSolar, developer of a breakthrough technology to produce bio-based materials from renewable plant sources, commented on a new analysis by New Energy Finance (citing a 50 percent drop in cost per kilowatt hour for solar panels through 2009, the “largest cost reduction in its history,” according to the report.

“Solar is widely hailed as the economic and environmental panacea for a greener future, but if the industry continues growing exponentially without planning ahead, it risks repeating the mistakes made by the microelectronics industry - now dealing with an ongoing legacy of toxic electronic waste,” said Lee.

“Solar is a renewable source of energy, but the upstream process of manufacturing solar panels is petroleum-dependant and involves a surprising number of toxic chemicals. With photovoltaic (PV) solar on track to reach grid party over the next several years, now is the time for the PV industry to get serious about life-cycles of all the materials that go into PV panels, starting from mining to manufacturing to recycling to disposal.”

In a recent article published by Design News, Lee explains the concept his company’s eco-friendlier bio-based backsheet solar cell component and addresses the toxicity concerns associated with polyvinyl fluoride (PVF) films currently used in the construction of 70 percent of solar modules.

According to Design News, “Tedlar is solvent-cast using an industrial solvent called dimethyl acetamide (DMAC), which can produce systemic injury when inhaled or absorbed through the skin in sufficient quantities over a prolonged period of time. If Tedlar® is burned, corrosive hydrogen fluoride fumes can be released. Another important issue: Tedlar has been in very short supply for the past two years because of its growing use in PV cells and aircraft interiors.”

Dr. Stan Levy, chief technology officer at BioSolar, who spent 27 years working on many of DuPont’s premier films, including Teflon, Mylar and Kapton, says he often fields questions within the PV industry regarding the manufacture and recycling of fluoropolymers such as Tedlar, including the most common, “What are the manufacturing issues with fluoropolymers? Are there any issues with burning fluorine-containing materials? Is NF3 (greenhouse gas) potential by-product? Are any fluoropolymers ‘safe’? What about recycling these, or having to put them in landfills?”

He also adds, “some polymers do not burn. Fluorocarbons such as TFE, PFA, and FEP need an atmosphere of at least 90 percent oxygen to ignite. Fluoroploymers, such as ‘Tefzel’ ETFE need an atmosphere of at lease 30% oxygen to ignite.” Levy warns, “they will decompose at a high enough temperature which is potentially extremely hazardous. The best method for disposal is landfill.”

According to November analysis by Norton Rose, a leading international legal practice, “The development of plant based polymers to replace the petroleum-based plastics used in the production of PV cells is taking place at BioSolar in California. It is hoped that their sustainable backsheet will allow c-Si cells to be truly green for the first time resulting in not just an eco-friendly development. By producing a backsheet which is not indexed to the cost of crude oil, it is expected that bio-based polymer technologies will significantly reduce costs.”

“BioSolar's products attack one of the conundrums of the emerging solar cell industry - they use millions of square feet of materials that are based on petroleum or require use of toxic chemicals to produce,” says Design News.

BioSolar recently announced that the BioBacksheet-C, an economical backsheet designed for the traditional c-Si PV modules, was qualified for production. Two more versions of BioBacksheet are currently in the pre-production stage moving towards qualification for full production, including BioBacksheet-A, designed with an absolute moisture barrier for thin-film modules.