Austere Location Wind Turbine Energy System Analysis

One promising technology to combat an energy shortage in austere locations is wind energy. In combination with battery storage and generator backup, we explore the feasibility of using a hybrid energy system to reduce the volume of diesel fuel required. Modeling the energy demands in austere locations will enable missions in remote settings to optimize their energy costs, increased their energy resiliency and assure their supply. For a modeled time-series energy requirement that varied between 2.4 MW and 5.1 MW, the optimal wind system size was 9.9 MW of installed wind power paired with a 741 kWh battery. Assuming an elevated price of fuel, the cost of operating the base with only fuel was greater than $55 million dollars. The total component and operational cost of the optimized wind, generator and battery system was cost-effective within one year and totaled$48 million dollars

36% Reduction in Fuel Resupply Using a Hybrid Generator & Battery System for an Austere Location

The DOD energy policy is to increase energy security resiliency, and mitigate costs in the use and management of energy[1] Forward operating bases (FOBs) are remote, austere base camps that support an operationally defined mission with a limited or no ability to draw from an energy grid and have historically relied on diesel-powered generators for the primary production of energy.[2] Generators are sized to meet a theoretical peak demand, but steady state loads are far below this peak, resulting in under-loaded generators.[3] Under-loaded diesel generators decrease efficiency and increase the need for maintenance, affecting the lifespan of the systems[4,5] This article analyzes the coupling of current power generation technology with energy storage. The addition of optimized energy storage to current diesel generators reduces fuel consumption by 36 percent and reduces energy system costs by 24 percent. Decreased fuel requirements at outlying FOBs equates to fewer resupply convoys, reducing operational fuel use, time spent outside the wire by service members and associated combat casualties. Abstract © Marine Corps Association

Photovoltaic System Optimization for an Austere Location Using Time Series Data

In this work we test experimental photovoltaic, storage and generator technologies and investigate their potential to meet austere location energy needs. After defining the energy requirements and insolation of a 1,100-person base, we develop a microgrid model and simulation. Cost optimizations were then performed using hourly time-series data to explore the cost and performance trade-space of a PV-battery-generator system. The work highlights the cost of resiliency and the dependencies of optimum system component sizes on duration and the fully burdened cost of fuel

Electronic and Structural Consequences of n-Doping: Bithiazole Oligomers and Partially Reduced Bithiazolium Cations

N-methylated-poly(diakyl-bithiazoles), NPABTs, can be reduced to give reasonably stable n-doped polymers. In order to understand the changes in the electronic structure and polymer conformations upon reductive doping of NPABTs, a series of oligomers of increasing length was studied by self-consistent field (AM1) and configuration interaction (ZINDO/S) calculations. Large red shifts in the optical transitions are predicted upon n-doping, along with significant planarization of chain segments. Full planarization was not realized for n-doped materials, however, as a variety of localized units were observed

Method for Thermal Management Through Use of Ammonium Carbamate

Ammonium carbamate-based methods and systems for management of thermal loads, particularly low-quality, high-flux thermal loads. The increase in temperature in heat sensitive devices is mitigated by the endothermic decomposition of ammonium carbamate into carbon dioxide and ammonia gases. This process has an energy density an order of magnitude greater than conventional thermal management materials and is particularly useful for temperatures between 20° C. and 100° C. Systems incorporating ammonium carbamate may be controlled by regulating the fluid flow, overhead pressure, temperature, or combinations thereof

The Use of Ammonium Carbamate as a High Energy Density Thermal Energy Storage Material

Phase change materials (PCMs) often have higher specific energy storage capacities at elevated temperatures. Thermal management (TM) systems capable of handling high heat fluxes in the temperature range from 20–100°C are necessary but lacking. State of the art PCMs in this temperature range are usually paraffin waxes with energy densities on the order of a few hundred kJ/kg or ice slurries with energy densities of the same magnitude. However, for applications where system weight and size are limited, it is necessary to improve this energy density by at least an order of magnitude. The compound ammonium carbamate, [NH4][H2NCOO], is a solid formed from the reaction of ammonia and carbon dioxide which endothermically decomposes back to CO2 and NH3 in the temperature range 20-100°C with an enthalpy of decomposition of ∼2,000 kJ/kg. Various methods to use this material for TM of low-grade, high-flux heat have been evaluated including: bare powder, thermally conductive carbon foams, thermally conductive metal foams, hydrocarbon based slurries, and a slurry in ethylene glycol or propylene glycol. A slurry in glycol is a promising system medium for enhancing heat and mass transfer for TM. Progress on material and system characterization is reported

CIS-DEFECTS IN TRANS-POLYENES

Author Institution: Air Force Research LaboratoryAll trans-polyenes have received tremendous experimental and theoretical attention because of their importance to vision and photosynthesis as well as conductive and semiconductive electronic applications. Numerous examples exist of cis-linkages contained in an otherwise all trans-polyene unit, such as the cis-trans isomerization associated with the vision process or the cis-polyacetylene formed initially in the Shirakawa synthesis of trans-polyacetylene. Though such cis-structures can have significant impact on optical, electronic, and nonlinear optical properties, such defects have received only scant attention. In this work, we report the results of ab initio calculations on the structure and properties of cis-defects embedded within all-trans-polyene units