SBIR-STTR Award

This Small Business Innovation Research Phase I project will develop a novel low-cost, high-performance fabric suitable for long service life helium inflatable structures, including aerostats and airships. Traditional fabrics for lighter-than-air (LTA) applications utilize woven polyester or vectran basecloths laminated with various materials that improve gas retention, environmental resistance and allow the material to be thermally bonded. This combination has excellent performance, providing a useful service life in excess of seven years, but comes at a high cost, which limits the commercial application of helium inflatable structures. The proposed low-cost, high performance fabric replaces the woven basecloth with a scrim of high-strength synthetic fibers, similar to those in high-end sailcloth. This type of material has not seen wide use in helium inflatable structures where seams are subject to long-term loading from internal pressure. The impact of scrim pattern and yarn alignment on seam stiffness and long-term holding strength is considered. This Phase I research will investigate the behavior of these materials, as well as one or more alternative woven fabrics, under long-term loading, UV exposure, and mechanical wear and tear, in order to evaluate their suitability for helium inflatables. The broader impact/commercial potential of this project will be a step toward the widespread commercialization of LTA inflatable structures in traditional and new application areas. Helium inflatable structures are traditionally used for transporting or elevating high value payloads, such as military surveillance equipment or advertising, where the relatively high cost of the fabric envelope is not a barrier to commercial feasibility. The advent of a low-cost, high performance helium inflatable fabric will make LTA structures economically viable for a number of industries that are cost-sensitive, including remote and emergency wireless communication; low-cost freight transport; and airborne wind energy production. The research will also enhance the understanding of the behavior of scrim-based fabrics under loading conditions, which may benefit a wide range of industries that could use these fabrics, including sailing, architectural fabrics and air inflatable structures

This Small Business Innovation Research (SBIR) Phase II project will develop an ultra-light, modular wind turbine for use in buoyant airborne wind energy systems. Reduced turbine weight has a cascading effect on total airborne system mass, allowing a significantly smaller, lower cost buoyant structure to be used to access high altitude winds. At heights up to 2,000 feet winds are strong and consistent, allowing for the production of low-cost, reliable power at a broad array of sites. High altitude winds have over five times the energy potential of ground winds accessed by tower-mounted turbines, opening the potential for a major new renewable energy resource to be harnessed. In addition, the containerized deployment of airborne wind turbines has the potential to expand wind development to sites that are not feasible today, including sites that are remote or have weak ground-level winds. Overall, the technology holds the potential to significantly lower energy costs and improve reliability for remote industrial, community, and military customers and represents a major step forward in unlocking the abundant high-altitude wind resource to help in the global pursuit of greater adoption of renewable energy sources. This SBIR Phase II project will focus on reducing the total weight of the wind turbine system. Turbine weight is one of the most critical cost drivers of buoyant airborne wind energy systems. For each kilogram removed from the turbine, an additional kilogram can be removed from the inflatable shell and tethers, resulting in a significantly smaller and lower cost system. The lightest commercially available small- to medium-sized wind turbine weighs 31.1 kilograms per kilowatt of capacity, which is too heavy for an economically-viable airborne turbine. By incorporating a compact, modular architecture, a lightweight permanent magnet direct-drive (PMDD) generator and high-strength composite materials, the proposed Phase II research effort aims to double the power density of traditional medium size turbines, making the proposed system suitable for use in an airborne application, while maintaining a high level of reliability and cost performance.