Integrated Tandem Dye Sensitized Solar Cell (DSSC)-Lithium Ion Battery

Efficient renewable energy harvesting and storage are needed for present challenges related to clean environment and increasing energy demand. Different types of energy harvesting technologies such as solar, thermal and wind require excess energy to be stored in batteries, which further adds to the complication and increase in cost to the overall renewable energy system. Integrating the generation and storage of solar energy in a single device would be a more cost effective way towards meeting the increasing energy demand due to its simplicity in design and less space consumptions. Herein, a sustainable photovoltaic cell integrated with an energy storage device was developed that addresses short term photovoltaic (PV) power variability using dye sensitized solar cell (DSSC) in a tandem structure with thin film based lithium-ion battery. As lithium based batteries have been addressed as efficient charge storage system due to its high energy storage density and extended lifecycle performance. The integrated structure uses a common anode (titanium foil coated with anatase TiO2 on both sides which serves as DSSC and lithium ion battery anode) which showed an open-circuit voltage of ~3 V, a short circuit current density of ~40mAhg-1 and a storage efficiency of ~0.80%. This new device can serve as power source to mobile storage applications

Dual-band substrate integrated waveguide textile antenna with integrated solar harvester

A dual-band wearable textile antenna based on substrate integrated waveguide technology is presented for operation in the [2.4-2.4835]-GHz Industrial, Scientific and Medical band and the [2.5-2.69]-GHz 4G LTE band 7. The antenna features an integrated flexible solar harvesting system, consisting of a flexible solar cell, a power management system, and energy storage. All these components are judiciously positioned on the antenna platform in order not to affect its radiation performance. The measured reflection coefficients and radiation characteristics after bending and deploying the antenna on a human body prove that the antenna is well suited for on-body use. A measured on-body antenna gain and radiation efficiency of 5.0 dBi and 89% are realized. Measurements in a real-life situation have demonstrated the ability to scavenge a maximum of 53 mW by means of a single integrated flexible solar cell

Fabrication and Characterization of Supercapacitors toward Self-Powered System

Ever increasing energy demand urges to impelled extensive research in the development of new eco-friendly energy harvesting and storage technologies. Energy harvesting technology exploiting renewable energy sources is an auspicious method for sustainable, autonomous, and everlasting operation of a variety of electronic devices. A new concept of an integrated self-powered system by combining an energy harvesting device with an energy storage device has been established to harvest renewable energy and simultaneously store it for sustainable operation of electronic devices. In this chapter, describes the fabrication of a self-powered system by integrating the supercapacitor with energy harvesting devices such as nanogenerator and solar cells to power portable electronic devices. Initially synthesis and electrochemical characterization of various electroactive materials for supercapacitors and further, fabrication of supercapacitor device were discussed. In conclusion, this chapter demonstrates self-powered system by the integration of energy harvesting, energy storage module with portable electronic devices. The various result validates the feasibility of using supercapacitors as efficient energy storage components in self-powered devices. The proposed self-powered technology based on energy conversion of renewable energy to electrical energy which stored in energy storage device and it will be used to operate several electronic devices as a self-powered device

Simulation and Measurement at Module for Energy Harvesting and Storing

Import 22/07/2015Tato bakalářská práce je zaměřena na metody získávání elektrické energie z okolního prostředí „Energy harvesting“. V práci jsou popsány jednotlivé možnosti sběru energie, a také možnosti jejího ukládání do paměťových prvků. Pro sběr a uchování energie slouží vývojový kit s integrovaným obvodem BQ25504. K integrovanému obvodu je jako zdroj energie připojen solární článek, a pro její uchování jsou použity kondenzátory. Hlavní vlastností tohoto řešení je jeho energetická soběstačnost a vysoká účinnost. Proto se dají solární články použít i za slabého osvětlení. Cílem bakalářské práce je pro zvolené zapojení provést návrh, kde jsou počítány jednotlivé prahové hodnoty pro správnou funkci IO. Na navrženém řešení integrovaného obvodu, bude provedena simulace a měření. Pomocí osciloskopů se změří průběhy nabíjení a vybíjení kondenzátorů, tyto průběhy budou analyzovány v textové části bakalářské práce.This thesis is focused on methods of obtaining electrical energy from the environment, "Energy harvesting". The paper describes the various possibilities energy harvesting, and also the possibility of storing in the memory elements. For collecting and storing energy used development kit with integrated circuit BQ25504. For integrated circuit is connected solar cell as a power source and for energy storage are used capacitors. The main feature of this solution is its energy self-sufficiency and high efficiency. Therefore, the solar cells can be used in low light. The aim of the thesis is design solutions, which are calculated by the individual thresholds for correct function. On the proposed solution integrated circuit will be a simulation and measurement. An oscilloscope is measured during charging and discharging capacitors, these waveforms will be analyzed in the text of thesis.450 - Katedra kybernetiky a biomedicínského inženýrstvívýborn

Thermo-optical performance of molecular solar thermal energy storage films

Due to their potential for solar energy harvesting and storage, molecular solar thermal energy storage (MOST) materials are receiving wide attention from both the research community and the public. MOST materials absorb photons and convert their energy to chemical energy, which is contained within the bonds of the MOST molecules. Depending on the molecular structure, these materials can store up to 1 MJ/kg, at ambient temperature and with storage times ranging from minutes to several years. This work is the first to thoroughly investigate the potential of MOST materials for the development of energy saving windows. To this end, the MOST molecules are integrated into thin, optically transparent films, which store solar energy during the daytime and release heat at a later point in time. A combined experimental and modeling approach is used to verify the system\u27s basic functionality and identify key parameters. Multi-physics modeling and simulation were conducted to evaluate the interaction of MOST films with light, both monochromatic and the entire solar spectrum, as well as the corresponding dynamic energy storage. The model was experimentally verified by studying the optical response of thin MOST films containing norbornadiene derivatives as a functional system. We found that the MOST films act as excellent UV shield and can store up to 0.37 kWh/m2 for optimized MOST molecules. Further, this model allowed us to screen various material parameters and develop guidelines on how to optimize the performance of MOST window films

High-Voltage Energy Harvesting and Storage System for Internet of Things Indoor Application

On the path toward independence from fossil fuels, solar energy is the mostpromising solution, but it needs a robust and reliable storage system to face itsintrinsicfluctuations due to location, day cycle, and weather. The integrationbetween energy harvesting and storage (H&S) technologies is a must toward cleanenergy production, and it becomes even more appealing considering the possi-bility of producing electricity not only from direct sunlight but also from diffuselight and indoor illumination. Herein, a dye-sensitized solar module (DSSM)developed to harvest indoor illumination and directly store it into an electricaldouble-layer capacitor (EDLC) is presented. Five series-connected dye-sensitizedsolar cells are fabricated on the same substrate and the module is integrated with ahigh-voltage EDLC. The integrated device is characterized under indoor lightsources such as light emitting diodes andfluorescent lamps. The results show oneof the highest efficiencies ever reported for a high-voltage DSSM under indoorillumination (16.27%), the largest voltage window ever reported for an indoor H&Sdevice based on DSSM and EDLC—up to 3 V—and an overall photoelectricconversion and storage efficiency of 9.73% under indoor illumination

Substrate integrated waveguide textile antennas as energy harvesting platforms

Textile multi-antenna systems are key components of smart fabric and interactive textile (SFIT) systems, as they establish reliable and energy-efficient wireless body-centric communication links. In this work, we investigate how their functionality can further be extended by exploiting their surface as an energy harvesting and power management platform. We provide guidelines for selecting an appropriate antenna topology and describe a suitable integration procedure. We demonstrate this approach by integrating two flexible solar cells, a micro-energy cell and a flexible power management system onto a well-chosen wearable substrate integrated waveguide cavity-backed textile slot antenna, without affecting its performance, to enable energy harvesting from solar and artificial light. In addition, the compact and highly-integrated harvesting module provides a terminal for connecting a thermoelectric generator, enabling thermal body energy harvesting. Measurements in a realistic indoor environment have demonstrated that this hybrid energy harvesting approach leverages a more continuous flow of scavenged energy, enabling energy scavenging in most of the indoor and outdoor scenarios

Wearable flexible lightweight modular RFID tag with integrated energy harvester

A novel wearable radio frequency identification (RFID) tag with sensing, processing, and decision-taking capability is presented for operation in the 2.45-GHz RFID superhigh frequency (SHF) band. The tag is powered by an integrated light harvester, with a flexible battery serving as an energy buffer. The proposed active tag features excellent wearability, very high read range, enhanced functionality, flexible interfacing with diverse low-power sensors, and extended system autonomy through an innovative holistic microwave system design paradigm that takes antenna design into consideration from the very early stages. Specifically, a dedicated textile shorted circular patch antenna with monopolar radiation pattern is designed and optimized for highly efficient and stable operation within the frequency band of operation. In this process, the textile antenna's functionality is augmented by reusing its surface as an integration platform for light-energy-harvesting, sensing, processing, and transceiver hardware, without sacrificing antenna performance or the wearer's comfort. The RFID tag is validated by measuring its stand-alone and on-body characteristics in free-space conditions. Moreover, measurements in a real-world scenario demonstrate an indoor read range up to 23 m in nonline-of-sight indoor propagation conditions, enabling interrogation by a reader situated in another room. In addition, the RFID platform only consumes 168.3 mu W, when sensing and processing are performed every 60 s

Printable magnesium ion quasi-solid-state asymmetric supercapacitors for flexible solar-charging integrated units.

Wearable and portable self-powered units have stimulated considerable attention in both the scientific and technological realms. However, their innovative development is still limited by inefficient bulky connections between functional modules, incompatible energy storage systems with poor cycling stability, and real safety concerns. Herein, we demonstrate a flexible solar-charging integrated unit based on the design of printed magnesium ion aqueous asymmetric supercapacitors. This power unit exhibits excellent mechanical robustness, high photo-charging cycling stability (98.7% capacitance retention after 100 cycles), excellent overall energy conversion and storage efficiency (ηoverall = 17.57%), and outstanding input current tolerance. In addition, the Mg ion quasi-solid-state asymmetric supercapacitors show high energy density up to 13.1 mWh cm-3 via pseudocapacitive ion storage as investigated by an operando X-ray diffraction technique. The findings pave a practical route toward the design of future self-powered systems affording favorable safety, long life, and high energy