Chemically deposited electrochromic cuprous oxide films for solar light modulation

Thin cuprous oxide electrochromic films on the transparent conductive electrodes were prepared by chemical electroless method. The films cycled in K⁺-based electrolyte revealed typical red-ox peaks with higher intensity compared to those in the Li⁺ and the Na⁺-based electrolytes. The durability of the cuprous oxide due to cycling into LiClO₄ was about 60 cycles. The thermal treatment of the films invoked decrease in red-ox peak intensity, and thus deterioration in the electrochromic properties. The response time of the coloration and bleaching to an abrupt voltage change from −4.5 to +4.5 V and reverse was found to be in the range of about 10 s. The maximum light intensity modulation ability of the films, as the AM1.5 spectrum is taken for an input, was calculated to be about 65%.     

A comparison of absorptance and reflectance modulation variable transmission electrochromic devices

A comparison is made of the optical properties and electrochromic performance of two types of electrochromic device for use as variable transmission glazing. The devices employ respectively amorphous tungsten oxide and crystalline tungsten oxide as the active electrochromic layer. Both devices exhibit pronounced transmission modulation. Some measure of reflectance modulation is observable for the crystalline tungsten oxide device.     

Design and fabrication of electrochromic light modulators

The battery-like structure of electrochromic devices warrants the application of a stoichiometric oxidation-reduction model to interpret and to optimize their operation. Of particular significance is the variation of the potential of electrochromic materials with composition, the bleached state absorption coefficients, their electrochemical stability limits and their coloration functionality versus Faradaic charge. Once these input parameters are known, the optical transmission spectrum of electrochromic light modulating devices can be predicted as a function of terminal voltage given certain assumptions about the thickness and redox state of the electrochromic and counter electrode materials on device assembly. The latter is not readily determined directly, but may be derived from properties of the two terminal device. Furthermore, the electro-optical characteristics of the two terminal device can be used to determine the source of any deviation from its optimal dynamic range.     

Reliability of rechargeable batteries in a photovoltaic power supply system

We investigated the reliability of a rechargeable battery acting as the energy storage component in a photovoltaic power supply system. A model system was constructed for this that includes the solar resource, the photovoltaic power supply system, the rechargeable battery and a load. The solar resource and the system load are modelled as stochastic processes. The photovoltaic system and the rechargeable battery are modelled deterministically, and an artificial neural network is incorporated into the model of the rechargeable battery to simulate damage that occurs during deep discharge cycles. The equations governing system behaviour are solved simultaneously in the Monte Carlo framework, and a first passage problem is solved to assess system reliability.     

Some suggestions for photovoltaic power generation using artificial light illumination

Part of the electrical energy spent for lighting purposes can be recycled by photovoltaic power generation. We have suggested some methods to enhance power generation based on solar cells using indoor artificial lights. An emergency street light system working on stored photovoltaic energy from outdoor sodium vapor lamp illumination is proposed as an application.     

Design, production and characterisation of an all solid state electrochromic medium size device

An electrochromic device based on a five layer coating deposited on a glass sheet was produced. The layers were all obtained by physical vapour deposition in the same vacuum environment, using a commercial apparatus capable of producing thin films on large area substrates. Small (50×50 mm²) and medium (300×300 mm²) size specimens were prepared for preliminary study, to establish the electrochemical and optical performances of the device. Electrochemical measurements were performed on each active material, as well as on the whole specimens, in order to relate electrochemical properties to process conditions. Also, luminous and solar parameters were obtained from (near) normal incidence spectrophotometry in both the bleached and coloured states, to confirm the values used in the design phase of the electrochromic device. One of the specimens was also submitted to variable angle photometric and radiometric measurements, using an integrating sphere. This data was then used to evaluate the room luminance distribution and energy loads using a building simulation code.     

Organic electrochromism for a new color electronic paper

We studied electrochemical properties of terephthalate derivatives, which showed reversible color change from clear to three primary colors by electrochemical stimuli, towards paper-like electronic imaging device. To improve the repetitive stability of the electrochromic cell, ferrocene was added to the electrolyte solution as electron donor (counter redox material). Passive-matrix operation (8×8) of electrochromic display (ECD) has been demonstrated. Moreover, a prototype three-layered ECD, which consisted of cyan, magenta and yellow primary-color layers, was also demonstrated to clarify the potential for full-color electronic paper.     

内燃机车冰箱电源的开发与研制

1前言 随着铁路跨越式发展,长交路列车使乘务员途中作业时间过长,乘务员吃饭难成为一个必须解决的问题.     

Devicenet现场总线特点及在低压配电装置中的应用

现场总线作为一种开放的、全数字化、双向、多站的通信系统、近年在各个自动化领域得到了迅猛的发展和应用。在范围内，目前已获得应用的现场总线已达数十种之多，而DeviceNet现场总线具有开放、高效和低价的特点，因此特别适合低压配电系统，制造业、工业控制等应用，对于低压配电设备尤其具有广阔的发展空间。     

Development of a thermoelectric self-powered residential heating system

Self-powered heating equipment has the potential for high overall energy efficiency and can provide an effective means of providing on site power and energy security in residential homes. It is also attractive for remote communities where connection to the grid is not cost effective. Self-powered residential heating systems operate entirely on fuel combustion and do not need externally generated electricity. Excess power can be provided for other electrical loads. To realize this concept, one must develop a reliable and low maintenance means of generating electricity and integrate it into fuel-fired heating equipment. In the present work, a self-powered residential heating system was developed using thermoelectric power generation technology. A thermoelectric module with a power generation capacity of 550 W was integrated into a fuel-fired furnace. The thermoelectric module has a radial configuration that fits well with the heating equipment. The electricity generated is adequate to power all electrical components for a residential central heating system. The performance of the thermoelectric module was examined under various operating conditions. The effects of heat transfer conditions were studied in order to maximize electric power output. A mathematical model was established and used to look into the influence of heat transfer coefficients and other parameters on electric power output and efficiency.     

High electrochromic performance of co-sputtered vanadium–titanium oxide as a counter electrode

This study examined the material and electrochromic properties of vanadium–titanium oxides (V–Ti oxides) as a counter electrode material in electrochromic devices. These oxides were deposited on an ITO substrate using a co-sputtering method at different levels of RF power. Electrochemical experiments of these oxides were carried out using half-cell and semi full-cell tests which are good methods for measuring the potential applied to each electrode. The change in electrochromic properties after 1000 cycles of a semi full-cell test was examined. Reversibility and durability of an electrochromic device were improved by increasing the titanium content in V–Ti oxides.     

The technical,geographical, and economic feasibility for solar energy to supply the energy needs of the US

So far, solar energy has been viewed as only a minor contributor in the energy mixture of the US due to cost and intermittency constraints. However, recent drastic cost reductions in the production of photovoltaics (PV) pave the way for enabling this technology to become cost competitive with fossil fuel energy generation. We show that with the right incentives, cost competitiveness with grid prices in the US (e.g., 6–10 US¢/kWh) can be attained by 2020. The intermittency problem is solved by integrating PV with compressed air energy storage (CAES) and by extending the thermal storage capability in concentrated solar power (CSP). We used hourly load data for the entire US and 45-year solar irradiation data from the southwest region of the US, to simulate the CAES storage requirements, under worst weather conditions. Based on expected improvements of established, commercially available PV, CSP, and CAES technologies, we show that solar energy has the technical, geographical, and economic potential to supply 69% of the total electricity needs and 35% of the total (electricity and fuel) energy needs of the US by 2050. When we extend our scenario to 2100, solar energy supplies over 90%, and together with other renewables, 100% of the total US energy demand with a corresponding 92% reduction in energy-related carbon dioxide emissions compared to the 2005 levels.     

Technology mix alternatives with high shares of wind power and photovoltaics—case study for Spain

The shift to a low carbon society is an issue of highest priority in the EU. For electricity generation, such a target counts with three main alternatives: renewable energies, nuclear power and carbon capture and storage. This paper focuses on the renewables’ alternative. Due to resource availability, a technology mix with a high share of PV and wind power is gaining increasing interest as a major solution for several EU member states and in part for the EU collectively to achieve decarbonization and energy security with acceptable costs. Due to their intermittency, the integration of high shares of PV and wind power in the electricity supply is challenging. This paper presents a techno-economic assessment of technology mix alternatives with a high share of PV and wind power in Spain, as an example. Thereby, the focus is on the option of increasing wind curtailment versus substituting rigid baseload generation in favor of the more flexible gas turbines and combined cycle gas turbines.     

Stress changes in electrochromic thin film electrodes:: Laser beam deflection method (LBDM) as a tool for the analysis of intercalation processes

The mechanical effects of the intercalation processes in electrochromic WO₃ thin films are reported here and discussed. In particular the electrochemical insertion of H, Li and Na ions in WO₃ was studied by means of laser beam deflection method (LBDM). Linear changes of WO₃ stress were observed for small amounts of the inserted charge and linearity was always associated with a reversible mechanical behavior of thin films. An explanation in terms of homogeneity of the insertion is given. An analogous trend was also verified in the absorbance vs. charge curves. As a consequence the constancy of the electrochromic efficiency values for the three different ions was found. In this way it was possible to determine a full reversible behavior for M_xWO₃ in the composition range 0x0.2. The onset of new phases formation when x exceeded previous upper limit, was observed during Li and Na intercalation. Such transitions brought about the loss of optical and mechanical reversibility. During prolonged hydrogen insertion a reversible slope inversion occurred in stress curve so that it was necessary to take into account different possible mechanisms of the WO₃ electrochromic reaction.     

新型海岸波浪发电装置的设计与分析

提出一种由发电机、蓄电装置、增速齿轮组、主轴、多组组件组成的利用波浪能发电的装置。多组组件安装在主轴上,每一组件包括弹簧外卡环、扭转弹簧、卷筒棘轮机构、浮子、绳子和定滑轮,当浮子随波浪上下浮动时,卷筒正反转,扭转弹簧提供卷筒反转的力,利用棘轮机构的单向运动特性、多组组件及增速齿轮组保证电机主轴连续单向高速旋转,达到发电目的。卷筒是该装置的主要受力部件,文中对其建立了有限元模型、进行了受力计算及边界条件的确定,应用simulation进行有限元分析,结果表明,对于给定的条件,卷筒刚度和强度均满足要求。     

Effect of citric acid on properties of CeO2 films for electrochromic windows

An alcohol based sol–gel process involving cerium chloride heptahydrate and citric acid in different mole ratios has been employed for the deposition of CeO₂ films. The structural, electrochemical, and optical properties of the films have been investigated using a wide range of techniques. Differential thermal analysis has shown the onset of crystallization of CeO₂ at 389 °C. The addition of an additive (citric acid) to the precursor sol has led to homogeneity and also a reduced ion storage capacity in the films. This observation emphasizes on the use of optimum content of the citric acid such that the films are suitable in terms of transparency as well as uniformity characteristics and also exhibit good electrochemical response. As is evidenced by the SEM study, the degree of polycrystalline grain formation in the citric acid derived films is observed to be less. The XPS results have confirmed the presence of Ce⁴⁺ state in the films. The optically passive behavior of the films is affirmed by their negligible transmission modulation upon Li ion insertion and extraction. A higher proportion of citric acid has also resulted in a reduced porosity and diminished crystallite size of the cerianite phase. The effect of the CeO₂ films on the switching kinetics of the tungsten oxide (WO₃) films has revealed an increase in the coloration time of the latter with the diminished crystallite size of CeO₂ nanograins in the former.     

Development of an electrical power take off system for a sea-test scaled offshore wave energy device

This paper details the design, deployment and operation of a power take off system for a 1:4 scale offshore Oscillating Water Column (OWC) Wave Energy Converter (WEC). Ocean energy device prototypes at this scale present a unique set of challenges in that the integration of prime movers and generators typically begins to take place at this particular development stage, which may also represent first deployment at sea.The presence of electrical equipment and rotating machinery in the offshore environment brings its own engineering and operational difficulties. Moreover, such devices are typically not grid connected, necessitating the development of custom power conversion and control equipment. The paper describes the design considerations, details of design, deployment experiences, operational experiences of such a system and concludes with recommendations for future projects in the area.     

新型太阳能光伏——热泵建筑供能系统的节能效益分析

研究设计合理的新型太阳能光伏-热泵建筑供能系统,在整个系统使用周期内所节省总费用作为初期投资的补偿,系统的使用周期为完成初期投资补偿所需的总年份。经过理论分析以及和常规能源使用成本进行比较分析,认为所设计系统具有良好的经济性,在使用寿命周期内能够获得较高效益。