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Due to the increasing trend in worldwide energy consumption, many new energy technology systems have emerged in the past decades. The implementation of energy storage system (ESS) technology in energy harvesting systems is significant to achieve flexibility and reliability in fulfilling the load demands. In this paper, several types of energy storage technologies available in the market are discussed to view their benefits and drawbacks. The main aim of this review is to provide a platform for readers especially those who seek to know more about ESS at a glance, to decide which ESS technology is best suited for any specific applications. This review would serve as a base for the initial state to make the right decision by referring to the criterias and characteristics of energy resources to get the optimal ESS technology. A comprehensive comparison among the various types of ESS technologies is outlined and elaborated to provide a better and clearer picture to the readers.  Last but not least, the relevant recommendations and alternative choices for services related to the harvesting of solar PV energy are described too. It is hoped that the findings of this review article may be helpful to all readers interested in ESS technology.

Smart meters are key elements for the operation of smart grids. By providing near realtime information on the energy consumption of individual users, smart meters increase the efficiency in generation, distribution and storage of energy in a smart grid. The ability of the utility provider to track users energy consumption inevitably leads to important threats to privacy. In this paper, privacy in a smart metering system is studied from an information theoretic perspective in the presence of energy harvesting and storage units. It is shown that energy harvesting provides increased privacy by diversifying the energy source, while a storage device can be used to increase both the energy efficiency and the privacy of the user. For given input load and energy harvesting rates, it is shown that there exists a trade-off between the information leakage rate, which is used to measure the privacy of the user, and the wasted energy rate, which is a measure of the energy-efficiency. The impact of the energy harvesting rate and the size of the storage device on this trade-off is also studied.

A device and method for harvesting, generating, storing, and delivering energy to a load, particularly for remote or inaccessible applications. The device preferably comprises one or more energy sources, at least one supercapacitor, at least one rechargeable battery, and a controller. The charging of the energy storage devices and the delivery of power to the load is preferably dynamically varied to maximize efficiency. A low power consumption charge pump circuit is preferably employed to collect power from low power energy sources while also enabling the delivery of higher voltage power to the load. The charging voltage is preferably programmable, enabling one device to be used for a wide range of specific applications.

We consider wireless transmission over fading channel powered by energy harvesting and storage devices. Assuming a finite battery storage capacity, we design an online power control strategy aiming at maximizing the long-term time-averaged transmission rate under battery operational constraints for energy harvesting. We first formulate the stochastic optimization problem, and then develop techniques to transform this problem and employ techniques from Lyapunov optimization to design the online power control solution. In particular, we propose an approach to handle unbounded channel fade which cannot by directly dealt with by Lyapunov framework. Our proposed algorithm determines the transmission power based only on the current energy state of the battery and channel fade conditions,without requiring any knowledge of the statistics of energy arrivals and fading channels. Our online power control solution is a three-stage closed-form solution depending on the battery energy level. It not only provides strategic energy conservation through the battery energy control, but also reveals an opportunistic transmission style based on fading condition, both of which improve the long-term time-averaged transmission rate. We further characterize the performance bound of our proposed algorithm to the optimal solution with a general fading distribution. Simulation results demonstrate a significant performance gain of our proposed online algorithm over alternative online approaches.

As many sensor network applications require deployment in remote and hard-to-reach areas, it is critical to ensure that such networks are capable of operating unattended for long durations. Consequently, the concept of using nodes with energy replenishment capabilities has been gaining popularity. However, new techniques and protocols must be developed to maximize the performance of sensor networks with energy replenishment. Here, we analyze limits of the performance of sensor nodes with limited energy, being replenished at a variable rate. We provide a simple localized energy management scheme that achieves a performance close to that with an unlimited energy source, and at the same time keeps the probability of complete battery discharge low. Based on the insights developed, we address the problem of energy management for energy-replenishing nodes with finite battery and finite data buffer capacities. To this end, we give an energy management scheme that achieves the optimal utility asymptotically while keeping both the battery discharge and data loss probabilities low.

This MURI project is aimed at designing a set of new energy-harvesting and storage materials (EHSM) and their integration of load-bearing airborne structures. The EHSM that were covered are, (i) organic solar cells based on two designs ,(a) dye-sensitized solar cells (DSSC) and (b) solid state semi-conductor polymer based solar cells(SSSPS), (ii) thermoelectric materials and modules, (iii) piezoelectrics and (iv) electromagnetic generator. This MURI team is composed of several universities, University of Washington (UW) , University of Colorado(CU), UCLA, Virginia Tech(VT) and University of Illinois(UI) at UC. UW team covers energy-harvesting and storage materials, and their integration to structures and supportive electric system, CU covers mainly the hierarchical modeling of EHSM, VT covers the multi-mode energy-harvesting system, UCLA covers mainly the integration of EHSS into load-bearing structures. Finally UI covers the micro-characterization of integrated EHSM into structures.

This MURI project is aimed at designing a set of new energy-harvesting and storage materials (EHSM) and their integration of load-bearing airborne structures. The EHSM that were covered are, (i) organic solar cells based on two designs ,(a) dye-sensitized solar cells (DSSC) and (b) solid state semi-conductor polymer based solar cells(SSSPS), (ii) thermoelectric materials and modules, (iii) piezoelectrics and (iv) electromagnetic generator. This MURI team is composed of several universities, University of Washington (UW), University of Colorado(CU), UCLA, Virginia Tech (YT) and University of lllinois (UI) at UC. UW team covers energy-harvesting and storage materials, and their integration to structures and supportive electric system, CU covers mainly the hierarchical modeling of EHSM,VT covers the multi-mode energy-harvesting system, UCLA covers mainly the integration of EHSS into load-bearing structures. Finally UI covers the micro-characterization of integrated EHSM into structures.

A device and method for harvesting, generating, storing, and delivering energy to a load, particularly for remote or inaccessible applications. The device preferably comprises one or more energy sources, at least one supercapacitor, at least one rechargeable battery, and a controller. The charging of the energy storage devices and the delivery of power to the load is preferably dynamically varied to maximize efficiency. A low power consumption charge pump circuit is preferably employed to collect power from low power energy sources while also enabling the delivery of higher voltage power to the load. The charging voltage is preferably programmable, enabling one device to be used for a wide range of specific applications.

The mechanical reliability and efficiency of thin film photovoltaics attached to structural members depends on the initial residual stresses in the films. In this research, accurate predictions of the mechanical and functional failure of photovoltaic films co-cured on carbon fiber composite laminates were made possible by quantifying the mean and gradient residual stresses and the failure properties of individual layers in thin film amorphous Si photovoltaics. The experimental results were employed to predict the onset of fragmentation in the transparent conductive oxide ZnO layer and the amorphous Si and the initiation of functional degradation of photovoltaic films co-cured on 0 degrees carbon fiber composite laminates. In parallel, this research program investigated the electrochemical and mechanical performance of graphite and Sn composite anodes subjected to electrochemical cycling. Most composite anodes reported in literature are very porous because they are manufactured from slurry, and as a result, they have no mechanical integrity. The composite graphite and Sn anodes fabricated in this research were prepared by hot pressing which allowed for control of their porosity between 35% and 75%. Porosities larger than 45% preserved the electrochemical capacity of the anodes, as opposed to those with porosities smaller than 40% that had reduced electrochemical capacity. Graphite anodes with 45% porosity demonstrated the highest retention of tensile strength and elastic modulus after 30 electrochemical cycles, representing an optimum condition. Finally, the fracture of Si as high capacity Li+ host material was investigated using Si microsprings. Experiments conducted under purely chemical lithiation, showed good lithiation and small propensity for crack formation, thus making films of such springs a viable material for high capacity thin film anodes.

A modular, integrated, completely solid-state system designed to harvest and store solar energy is under development. Called the power tile, the hybrid device consists of a photovoltaic cell, a battery, a thermoelectric device, and a charge-control circuit that are heterogeneously integrated to maximize specific energy capacity and efficiency. Power tiles could be used in a variety of space and terrestrial environments and would be designed to function with maximum efficiency in the presence of anticipated temperatures, temperature gradients, and cycles of sunlight and shadow. Because they are modular in nature, one could use a single power tile or could construct an array of as many tiles as needed. If multiple tiles are used in an array, the distributed and redundant nature of the charge control and distribution hardware provides an extremely fault-tolerant system. The figure presents a schematic view of the device.