WASHINGTON--(BUSINESS WIRE)--As the world’s first solar-powered airplane to fly both day and night touched down early Sunday in Washington, all eyes focused on the odd-shaped plane and its pioneering pilots.
Equally significant is the science and innovative technology behind the concept of the Solar Impulse aircraft. From lightweight, high-strength plastics, to thin, protective films covering the solar panels, new technologies in advanced materials have provided durability and energy efficiency to propel Solar Impulse thousands of miles “Across America” without a drop of fossil fuel.
Special materials and expertise from Solvay, a global producer of chemicals and advanced materials, optimize the aircraft’s energy chain and contribute to the plane’s remarkably light, yet sturdy, structure.
Solvay is a founding partner of the Solar Impulse consortium that also includes companies with expertise in solar technologies, aviation, engineering, electronics, mechanics and controls.
In a panel discussion today at Washington’s National Press Club, Solvay’s Solar Impulse Partnership Manager Claude Michel described the challenges in designing and building the plane. “Weight is an obsession with Solar Impulse,” he said.
According to Michel, for every 8kg — whether it’s 8kg of plane, pilot or equipment — Solar Impulse needs one square meter of solar panels. The solar panels are spread across the upper portion of the aircraft’s horizontal stabilizer and wings which, at 63 meters, are the span of a commercial jet. That wingspan accommodates enough panels that Solar Impulse can carry just 1600kg. A typical four-engine propeller-driven commercial airliner weighs about 30 times more.
“Every piece of the plane is evaluated for its weight as well as its effectiveness,” he said. “Every gram is measured.”
Michel explained key ratios of solar panel surface areas to energy produced, stored and consumed on board, and how high-strength plastics, insulation, lubricants and protective films contribute to the plane’s light weight as well as its energy efficiency.
“Many of these technologies found novel applications on Solar Impulse,” Michel explained, “but the specific products already existed, and are commercially available today for many manufacturing uses.”
George Corbin, head of research, development and technology for Solvay Specialty Polymers, provided several examples of Solvay products with new uses on Solar Impulse. He cited Halar® ECTFE, a copolymer of ethylene and chlorotrifluoroethylene, that is specially processed for Solar Impulse into a film that it is just 20 microns, or about .001 inches---thinner than a human hair.
Traditionally designed as a coating material for protection and anti-corrosion applications, Halar was adapted in 2008 for Solar Impulse, where it is the photovoltaic front sheet.
Corbin also explained how key components of the Solar Impulse wings came together---literally. He explained how Solar Impulse’s wing spar is formed from a lightweight paper honeycomb sandwiched between two layers of carbon fiber.
The paper honeycomb structure is coated with Solvay’s Torlon®, an aqueous solution polyamide-imide (PAI) with the highest strength and stiffness of any thermoplastic up to 275°C (525°F). Torlon resins serve as an adhesive that sticks together the pieces of paper that create the honeycomb.
In addition to adhesives products, Solvay also offers a version of Torlon PAI that can be injection molded or extruded into parts. Components made from Torlon PAI are also found on the Solar Impulse and commercial aircraft as well.
Eleven different Solvay products are used in 20 different applications and 6,000 parts of the Solar Impulse. “Solvay has sponsored this project since its inception in 2004 because we are deeply committed to sustainability principles including alternate energy technologies, and we wanted to challenge ourselves in this domain,” explained Corbin. “We're proud to see our sustainability vision realized through this remarkable technical achievement.”
In addition to Michel and Corbin, today’s science and technology panel at the National Press Club included Darcy Gentleman of the American Chemical Society’s office of public affairs, Science & the Congress Project. ACS co-hosted the Solar Impulse panel presentation at the National Press Club.
As an international chemical group, SOLVAY assists industry in finding and implementing ever more responsible and value-creating solutions. The Group is firmly committed to sustainable development and focused on innovation and operational excellence. Solvay serves diversified markets, generating 90% of its turnover in activities where it is one of the top three worldwide. The group is headquartered in Brussels, employs about 29,000 people in 55 countries and generated 12.4 billion euros in net sales in 2012. Solvay SA (SOLB.BE) is listed on NYSE Euronext in Brussels and Paris (Bloomberg: SOLB.BB - Reuters: SOLBt.BR).
