Abstract: A multi-functional, multi-layer film or skin which may be used as a covering for a structure or platform incorporates an integrated photovoltaic element and an integrated RF antenna element. The film or skin is suitable for use in various applications, including those involving autonomous, self-powered, mobile communication systems and especially for use as a skin or covering for solar powered aircraft and UAVs. Planar PV cells and planar RF antenna are used to facilitate their integration into the film or skin. The PV cells and RF antenna are configured to face operate outward from opposite faces of the skin. The film or skin addresses potential problems arising from conflicting directional requirements for PV orientation and antenna pointing on mobile platforms. This is accomplished by employing wide angle AR coatings on the PV elements and electrical controls to steer the RF antenna.

Abstract: Embodiments of the present invention provide an alternative distributed airborne transportation system. In some embodiments, a method for distributed airborne transportation includes: providing an airborne vehicle with a wing and a wing span, having capacity to carry one or more of passengers or cargo; landing of the airborne vehicle near one or more of passengers or cargo and loading at least one of passengers or cargo; taking-off and determining a flight direction for the airborne vehicle; locating at least one other airborne vehicle, which has substantially the same flight direction; and joining at least one other airborne vehicle in flight formation and forming a fleet, in which airborne vehicles fly with the same speed and direction and in which adjacent airborne vehicles are separated by distance of less than 100 wing spans.

Abstract: Methods and apparatus for supplying power to an electrical line or grid by using high-frequency alternating current (HFAC) are provided herein. In some embodiments, an apparatus for collecting and transmitting electrical power to an AC line operating at a line frequency may include a plurality of high frequency AC power sources; a high frequency AC bus, connected to each of the high frequency AC sources; and a line frequency converter, the input of which is connected to the high frequency AC bus and the output of which is connectable to the AC line.

Abstract: A multi-input electrical power conversion device is provided for converting multiple DC energies each arising from different junctions in a multi-junction solar cells into AC energy. The device includes a plurality of electrical inputs for receiving the multiple DC energies from at least one multi junction solar cell. The number of DC energies id no less than the number of junctions in the multi-junction solar cell. The device also includes at least one DC-to-AC circuit for receiving the multiple DC energies from the plurality of electrical inputs and at least one electrical output receiving at least one AC energy from the DC to AC circuit. The device also includes at least one MPPT circuit operatively coupled to the DC to AC circuit.

Abstract: A multilayer film or skin for free space optical data transmission includes a first outer layer. The first outer layer has a first laterally extending area that transmits optical data signals received over a range of incident angle. A second layer that includes a second laterally extending area underlies the first layer. At least a portion of the optical data signals received by the second layer from the first outer layer is focused or otherwise concentrated into a substantially reduced area. An optical detector receives the concentrated optical data signals from the second layer. An electrical connection extends from the optical detector to an external receiving device. The multilayer film or skin may be used, for example, in applications involving mobile free space optical communication platforms where low profile, volume and mass and/or enhanced platforms are important.

Abstract: Embodiments of methods and apparatus for providing distributed airborne wireless communications are provided herein. In some embodiments, a communication fleet includes: an airborne communication payload subdivided into multiple payload sections; and a plurality of airborne platforms each including a payload section, wherein each airborne platform comprises an airframe, a propulsion system, a power system, and flight control electronics, wherein the propulsion system is configured to provide propulsion power and thrust to maintain level flight, ascend, descend and maneuver the airborne platform, wherein the power system provides electrical power to the propulsion system, the flight control electronics, and the payload section, and wherein the flight control electronics provide capability to control a position, speed, and flight pattern of the airborne platform.

Abstract: Methods and apparatus are provided for using a renewable source of energy such as solar, wind, or geothermal energy. In some embodiments, the method may include generating electric energy from a renewable form of energy at a plurality of locations at which reside an electric power line associated with an electric power grid. The electric energy generated at each location may be transferred to the electric power line to thereby supply electric energy to the electric power grid.

Abstract: A photovoltaic device is provided which includes a plurality of junction layers. Each junction layer includes a plurality of photovoltaic cells electrically connected to one another. At least one of the junction layers is at least in part optically transmissive. The junction layers are arranged in a stack on top of each other.

Abstract: Embodiments of methods and apparatus for providing distributed airborne wireless communications are provided herein. In some embodiments, an airborne wireless communication node includes: an airborne fleet comprising a plurality of airborne platforms having flight control electronics configured to control flight of individual airborne platforms and coordinate a flight plan of the airborne fleet as a whole; and a distributed communication payload, wherein the communication payload is subdivided into constituent parts, wherein the parts are distributed and positioned on respective ones of the plurality of airborne platforms.

Abstract: Methods and apparatus for an adaptable solar airframe are provided herein. In some embodiments, an adaptable solar airframe includes an expandable body having an aerodynamic cross-section that reduces parasitic air drag at any given thickness of the body, further being able to change its shape in flight in response to changes in the relative position of the sun; and a flexible solar PV system attached to the surface of the expandable body.

Abstract: Methods and apparatus to harvest renewable energy are provided herein. In some embodiments, a method to harvest renewable energy includes providing an aircraft suitable for untethered flight in an open airspace and an airborne kinetic energy conversion system attached to the airframe, the airborne kinetic energy conversion system comprising a turbine, a generator connected to the turbine, and electrical storage means connected to the generator; flying the aircraft; gaining excess kinetic energy; and converting excess kinetic energy into electricity using the kinetic energy conversion system.

Abstract: An ice resistant structure is provided which includes a self-supporting, structural platform, a retaining, protective layer and a subsurface anti-icing (AI) and/or de-icing (DI) layer. The retaining, protective layer is disposed over the self-supporting, structural platform. The subsurface anti-icing (AI) and/or de-icing (DI) layer is located between the self-supporting, structural platform and the retaining, protective layer. The subsurface Al and/or DI layer is a functional layer such that an Al and/or DI agent is released to a surface of the retaining protective layer by an activation mechanism responsive to a change in an environmental condition.

Abstract: A stretchable photovoltaic device, a stretchable photovoltaic module and a carrier for facilitating formation of a stretchable photovoltaic device and/or module are provided. The stretchable photovoltaic device includes a stretchable part, at least one photovoltaic cell and a surface over which that at least one photovoltaic cell is disposed. The stretchable part has a given length that is operable to change in response to a force being applied to the device. The given length may, for example, elongate when the force causes the device to elongate. Alternative and/or additionally, the given length may compress when the force causes the device to compress.

Abstract: Methods and apparatus to harvest renewable energy are provided herein. In some embodiments, a method to harvest renewable energy includes providing an aircraft suitable for untethered flight in an open airspace and an airborne kinetic energy conversion system attached to the airframe, the airborne kinetic energy conversion system comprising a turbine, a generator connected to the turbine, and electrical storage means connected to the generator; flying the aircraft; gaining excess kinetic energy; and converting excess kinetic energy into electricity using the kinetic energy conversion system.

Abstract: Methods and apparatus to harvest renewable energy are provided herein. In some embodiments, a wind-powered aircraft includes an airframe suitable for untethered flight in an open airspace; and an airborne kinetic energy conversion system attached to the airframe, the airborne kinetic energy conversion system comprising a turbine, a generator connected to the turbine, and an electrical storage means connected to the generator.

Abstract: Embodiments of apparatus for providing distributed airborne wireless communications are provided herein. In some embodiments, a distributed communication payload includes: a payload control electronics module; an air-to-user link module to provide wireless communication links between airborne platforms and end-user devices; and an air-to-air link module to provide wireless communication links between airborne platforms; wherein the air-to-user and air-to-air link modules are subdivided into multiple sections that can be disposed on different airborne platforms.

Abstract: Embodiments of apparatus for providing distributed airborne wireless communications are provided herein. In some embodiments, a distributed communication payload includes: a payload control electronics module; an air-to-user link module to provide wireless communication links between airborne platforms and end-user devices; and an air-to-air link module to provide wireless communication links between airborne platforms; wherein the air-to-user and air-to-air link modules are subdivided into multiple sections that can be disposed on different airborne platforms.

Abstract: A method of: providing one or more spent sputtering targets comprising a photovoltaic compound and grinding the photovoltaic compound in an inert environment to form a powder.

Abstract: A photovoltaic device is provided which includes a plurality of junction layers. Each junction layer includes a plurality of photovoltaic cells electrically connected to one another. At least one of the junction layers is at least in part optically transmissive. The junction layers are arranged in a stack on top of each other.

Abstract: Methods and apparatus for an adaptable solar airframe are provided herein. In some embodiments, an adaptable solar airframe includes an expandable body having an aerodynamic cross-section that reduces parasitic air drag at any given thickness of the body, further being able to change its shape in flight in response to changes in the relative position of the sun; and a flexible solar PV system attached to the surface of the expandable body.