Energy

Optical Fiber for Solar Cells

These materials enable new solar-powered devices that are small, lightweight, and can be used without connection to existing electrical grids. Ames Research Center, Moffett Field, California Polymeric and inorganic semiconductors offer relatively high quantum efficiencies, and are much less expensive and versatile to fabricate than non-amorphous silicon wafers. An optical fiber and cladding can be designed and fabricated to confine light for transport within ultraviolet and near-infrared media, using evanescent waves, and to transmit visible wavelength light for direct lighting.

Posted in: Briefs, Energy Storage, Solar Power, Fiber Optics

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Pumped Subsea Energy Storage

This technique would be applicable to offshore oil platforms and energy storage for public utilities. NASA’s Jet Propulsion Laboratory, Pasadena, California A local energy source is desired for near-shore and offshore applications. Gas generators, diesel generators, and long-length submerged power cables tend to be expensive. A proposed solution is to use offshore wind with some type of energy storage mechanism for up to 1 GW-h. Energy storage in batteries is too expensive and massive, and subsea compressed air energy storage (CAES) has not been proven for very deep depths. Furthermore, CAES involves very great temperature changes that result in large inefficiencies.

Posted in: Briefs, TSP, Energy Efficiency, Energy Storage, Solar Power, Wind Power

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Carbon Nanotube Tower-Based Supercapacitor

Ames Research Center, Moffett Field, California A new technology to create electrochemical double-layer supercapacitors is provided using carbon nanotubes as electrodes of the storage medium. This invention allows efficient transport between the capacitor electrodes through the porous nature of the nanotubes, and has a low interface resistance between the electrode material and the collector. Carbon nanotubes directly grown on a metal surface are used to improve the supercapacitor performance. The nanotubes offer a high surface area and usable porosity for a given volume and mass, both of which are highly desirable for supercapacitor operation.

Posted in: Briefs, Energy Storage

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Design for Improving the Flatness of Solar Sails

An optically flat solar sail could be useful in optical communication and solar energy applications. NASA’s Jet Propulsion Laboratory, Pasadena, California This work describes a discontinuous or segmented mirror whose overall flatness is less dependent on the limited tension that can be supplied by the booms. A solar sail is a large, nominally flat sheet of extremely thin reflectorized film rigidly attached to a spacecraft, enabling propulsion via solar radiation pressure. Rip-stop fibers embedded in the backside of the film — with diameters ≈100× the thickness of the film — are commonly used to arrest tear propagation, which can easily occur in the handling and/or deployment of these gossamer-thin structures. Typically, the thin film or membrane that is the sail is systematically folded to enable both volumetrically compact transportation to space and mechanized deployment. It is the aggressive folding and creasing of the thin film that limits the ultimate flatness that can be achieved.

Posted in: Briefs, TSP, Solar Power

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Negative Dielectric Constant Material Based on Ion-Conducting Materials

Langley Research Center, Hampton, Virginia Metamaterials, or artificial negative index materials (NIMs), have generated great attention due to their unique and exotic electromagnetic properties. A negative dielectric constant material, which is an essential key for creating the NIMs, was developed by doping ions into a polymer, a protonated poly(benzimidazole) (PBI).

Posted in: Briefs, TSP, Energy Storage, Sensors

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Energy Efficiency in Machine Tools

Discussions of the efficient use of energy have become more frequent in many sectors of industry. Machine tools comprise numerous motors and auxiliary components whose energy consumption can vary strongly during machining. The main spindle drive, for example, and the coolant system work near their rated power during roughing with a high stock removal rate, while the power consumption during finishing is significantly lower. There is a very close interdependence between the individual components and subassemblies of a machine tool and aspects of productivity and quality. From a detailed examination of manufacturing processes to the power consumption of individual components, potential for savings can be evaluated and measures can be defined for the efficient use of energy.

Posted in: Application Briefs, Articles, Energy Efficiency, Motors & Drives, Machinery & Automation

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Variable-Sweep-Wing Aircraft Configuration

There are significant improvements in structural, aerodynamic, and energy efficiency. Ames Research Center, Moffett Field, California Efficient aircraft designs are increasingly desired in order to support the continued growth of the air transportation industry. Continued expansion of this vital mode of transportation is threatened due to concerns over ever-increasing emissions, noise, and the demand for fuel. Current airport runway, ramp, and terminal facilities are increasingly constrained by encroaching growth and neighborhood environmental issues. The challenges associated with ever-increasing demand for air travel will require the development of aircraft that can fly efficiently over wide speed ranges, minimize their environmental impacts, offer the potential for sizing and growth relative to market demand, and make efficient use of constrained airport and airspace resources.

Posted in: Articles, Briefs, Aviation, Energy Efficiency

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