Simultaneous desalination and power generation using solar energy

Using solar energy to produce fresh water and electricity simultaneously is a prospective way to solve the problems combining fresh water shortage, energy crisis and farm land degradation in Northern Victoria. This paper records the process of calculating the performance of the nozzle applying homogenous equilibrium model, designing and testing the prototype of such system using three different types of the nozzles in static and rotary systems. The research on the project is divided into two steps: first is about static system in which the spray nozzle is proved to be the best in both production of fresh water and power generation; while on the second stage, the convergent–divergent (C–D) nozzles are the best in rotary system. Some data were analyzed theoretically based on the test and the results found that the percentage of fresh water measured by experiment is consistent with the calculation using homogenous equilibrium expansion model (HEM), however, there is big difference in power generation between theory and experiments. Based on our experimental figures and analysis, the reasons for low power generation are found and a new model is proposed. According to the new model, a different reaction turbine using curve length C–D nozzles is designed to overcome the problems which were encountered in the previous prototype. After analyzing the efficiency of the cycle by T–s diagram, the evacuated tube solar collector integrated heat pipe is suggested to be applied on this system.     

太阳能热发电的显热蓄热技术进展

介绍了太阳能热发电显热蓄热的3种技术:单一流体蓄热,直接接触蓄热和间接接触蓄热。单一流体蓄热,主要有导热油、熔融盐和蒸汽3种选择。直接接触蓄热,使用廉价材料作为蓄热介质,节约了成本。间接接触蓄热使模块化安装成为可能,进一步克服了直接接触蓄热的缺点,为蓄热技术发展提供了便利。     

Performance study of power density in PEMFC for power generation from solar energy

A study has been carried-out on power density in the Proton Exchange Membrane Fuel Cell (PEMFC) for its application for solar power generation. It involves a fuel cell approach assisted with specific electro-catalysts to process special chemical coupling (2-propanol/acetone/H₂) for generating the power. This knowledge will be useful for designing the solar power generation system based on this special chemical coupling enabling to use low-grade solar heat (<100 °C). For this purpose, a wide study has been conducted in the PEMFC using different catalytic electrodes at various orientations (0°, 45° and 90°). The investigations were carried-out at different temperatures from 45 °C to 60 °C using liquid oxidant mixtures in different proportions. The maximum power density attained was 1.78 mW cm^?2 at 60 °C. The PEMFC based technique for solar power generation may prove to be a promising option to harness this everlasting source of sun’s energy in the coming future.     

The value of solar: Prices and output from distributed photovoltaic generation in South Australia

The Australian government's Solar Cities Program sees great value in so-called “cost-reflective pricing”, code for valuing solar at pool prices. We test that proposition in South Australia where pool prices and insolation are often high and we show that there were few days in 2004 when the pool price gives better outcomes than if the solar is valued at the regulated and fixed, so-called standing contract price. We also find that the illustrative day used in the Solar Cities Program literature to promote the notion of cost-reflective pricing is highly atypical. Finally, we consider ways in which the incentive to install distributed photovoltaic generation might be improved.     

某15MW太阳能屋顶光伏发电工程的应用分析

在对太阳能屋顶光伏发电系统构成及发展意义阐述的基础上,通过对某15MW屋顶光伏发电工程大量实际数据的分析,表明太阳能屋顶光伏发电工程具有良好的社会、经济效益和广阔的发展前景。     

太阳能热发电系列文章(8)槽式太阳能热发电DSG技术

太阳能热发电是太阳能热利用的重要方向,是最可能引起能源革命的技术成果,是实现大功率发电、替代常规能源的最为经济的手段之一。太阳能热发电的三种方式各自优缺点非常明显,如:塔式效率高,但一次性投入大;槽式成本低,但相对塔     

Spatio-temporal variability of solar energy across a region: a statistical modelling approach

Solar energy collected at a number of discrete sites, which are dispersed over a geographical area, will exhibit both spatial and temporal variability. Being able to model this variability will have many applications, for example in controlling an electricity system that is supplied by decentralised PV arrays. This paper describes a statistical modelling study of solar data that were recorded over 2 years at a total of 22 sites in the city of Edinburgh, Scotland, and in the nearby Pentland hills. A spatio-temporal model is proposed for global irradiation on a horizontal plane: this incorporates the sum of two exponentials to model the decrease in covariance between sites with time lag, and a space–time term to model the combined dependence of covariance on time lag and easterly distance.     

Net energy analysis of solar and conventional domestic hot water systems in Melbourne, Australia

It is commonly assumed that solar hot water systems save energy and reduce greenhouse gas emissions. The net energy requirement of solar hot water systems has rarely been analysed, including their embodied energy. The extent to which solar hot water systems save energy compared to conventional systems in Melbourne, Australia, is shown through a comparative net energy analysis. It was shown that the embodied energy component of the net energy requirement of solar and conventional hot water systems was insignificant. The solar hot water systems provided a net energy saving compared to the conventional systems after 0.5–2 years, for electric- and gas-boosted systems respectively.     

Emerging technologies to power next generation mobile electronic devices using solar energy

Mobile electronic devices such as MP3, mobile phones, and wearable or implanted medical devices have already or will soon become a necessity in peoples’ lives. However, the further development of these devices is restricted not only by the inconvenient charging process of the power module, but also by the soaring prices of fossil fuel and its downstream chain of electricity manipulation. In view of the huge amount of solar energy fueling the world biochemically and thermally, a carry-on electricity harvester embedded in portable devices is emerging as a most noteworthy research area and engineering practice for a cost efficient solution. Such a parasitic problem is intrinsic in the next generation portable devices. This paper is dedicated to presenting an overview of the photovoltaic strategy in the chain as a reference for researchers and practitioners committed to solving the problem.     

太阳能与燃煤机组集成发电系统的研究现状

介绍了太阳能与燃煤机组集成发电系统的发展背景、国内外发展状况以及集成方式,对太阳能与回热系统集成等三种集成方式进行了比较,分析了几种提高集成发电系统经济性的优化方式,指出了发展中存在的一些问题及发展前景。     

Short-term variability of solar radiation

This paper presents a study of the variability of solar radiation in the minute-long time range. The solar climate in Northern Europe is classified in this paper as being either stable, or highly variable, due to stochastic cloud cover inducing fluctuations of the solar irradiance. In general, solar radiation exhibits both positive and negative increments in the radiation during any period. The distribution functions of these increments with respect to their magnitude and duration are investigated, as well the distribution functions of stable intervals during generally variable radiation. The distribution functions are found to be a superposition of two exponential functions with different exponents, which depend on the magnitude of the radiation increments.     

太阳能在建筑节能中应用的探讨

论述了太阳能在建筑中的应用形式,对不同的形式做了必要的分析。提出了使用中应注意的问题,并得到一些结论。     

Solar versus fossil fuels : A net energy analysis of domestic solar hot water systems in Australia

It is commonly assumed that solar hot water systems save energy and reduce greenhouse gas emissions compared to conventional electric and gas hot water systems. Very rarely has the life-cycle energy requirements (including the embodied energy of manufacture) of solar hot water systems been analysed. The extent to which solar hot water systems can save energy compared to conventional electric or gas hot water systems can be shown through a comparative net energy analysis. This method determines the ‘energy payback period’, including consideration of the difference in operational energy savings and energy embodied in the devices relative to a base case. Dr Robert Crawford, Deakin University, Australia presents the results of a net energy analysis that compared solar and conventional hot water systems for a southern (Melbourne) and a northern (Brisbane) Australian climate.     

太阳能的特点

太阳能虽然有许多常规能源或其他新能源所没有的优点,但也存在它本身所固有的缺点。在利用太阳能时,就应该“扬长避短”,也就是说,要充分利用和发扬它的优点,同时尽量避免和克服它的缺点,只有这样,才能最大限度地发挥它的效能和威力。下面就来分别介绍一下它的优点和缺点以及克服缺点的办法。     

Parameterization of daily solar irradiance variability

The effects of solar systems operation can be compared only under very similar weather conditions. Diagnostics of the solar systems requires unequivocal determination of solar irradiation. Development of a method for precise identification of solar radiation day time profile is needed, as the methods used so far in the cloud cover determination are not satisfactory. The paper presents two optional methods, developed by the authors, for identification of the solar radiation profile. Advantages and disadvantages of the methods are also specified.     

Performance of experimental solar water heaters in Australia

Seven experimental solar water heaters were installed at C.S.I.R.O. laboratories throughout Australia in order to gain field experience and performance data for various localities. Each heater included an insulated 70-gal hot water storage tank with a built-in electric booster and two solar absorbers of total active area of 45 sq ft.

Each morning approximately 45 gal of water at a temperature of about 135°F were discharged from the tank. Average monthly values for a 12-month period are given for the daily electric power consumption and the solar contribution. Mean yearly contribution of the solar energy under these conditions was from 60 to 80 per cent of the total energy required, depending on the district in which the heaters were located. In order to determine the extent to which the results are typical, a comparison is given, for some of the districts, of the sunshine hours recorded during the test period, with the nominal 30-year average.     

内蒙古太阳能资源的分布特征与光伏发电开发的可行性分析

利用修正后的Angstr(a|¨)n-Prescott模型,结合内蒙古各气象站观测的日照资料,绘制了全区太阳辐射分布图,对其资源分布特性进行了分析,并对后续开发和利用进行了区划。针对光伏发电的规划和开发给出合理化建议,为当地的可再生能源的发展提供研究基础。     

Exploitation of solar energy in Cyprus

This paper reviews the application of solar energy technology in Cyprus and presents an energy analysis with emphasis on the contribution of solar energy to the energy consumption in the island. The almost full reliance of Cyprus on imported oil to meet its energy demand, together with the abundance of solar radiation and a good technological base, created favourable conditions for the exploitation and development of solar energy in the island. Cyprys began manufacturing solar water heaters in the early 1960s and today it produces more than 30,000 m² of solar collectors yearly. It is estimated that more than 130,000 solar water heaters are in operation providing the equivalent of 9% of the total electricity consumption in the country; this corresponds to, approximately, 4% of the national energy consumption. However, the use of solar energy for space heating and cooling provides a further challenge, because it does not appear to be economic under the climatic conditions and system design practices currently prevailing in Cyprus. The paper provides a statistical analysis of the energy demand and identifies areas of further growth for solar energy technology.     

太阳能在暖通空调中的应用

介绍了丰富且清洁无污染的太阳能在暖通空调领域中采暖、热水系统和制冷等方面的应用,指出将太阳能热利用与建筑节能设备合理整合,必将对开发节能环保型可持续发展的空调技术做出巨大贡献。     

Second generation CIS solar modules

Multinary Cu(In,Ga)(Se,S)₂ absorbers (abrev. CIGSSe) are promising candidates for reducing the cost of photovoltaics well below the cost of crystalline silicon. Shell Solar has pioneered production of this new thin film technology and is now with the first generation at a volume of well over 1 MW/year. In a separate pilot line for second generation products we have further improved the performance of CIGSSE based solar modules. We developed a novel CIGSSE formation technique called stacked elemental layer rapid thermal processing (SEL-RTP). This process has recently been scaled up from initial laboratory sized mini-modules (10 × 10 cm²) to full sized power modules of 60 × 90 cm². The present paper concentrates on in situ and ex situ characterization techniques that were developed to control and further improve large area CIGSSE processing. The crystalline thin film formation process has been analyzed with in situ thin film calorimetry and in situ X-ray diffraction (XRD). That work has added fundamental insights and accelerates the optimization process. The depth distribution of gallium and sulfur has been determined by secondary ion mass spectroscopy (SIMS) for different selenization and sulfurization processes. Appropriate profiles of these elements allow for a deliberate bandgap profiling within the Cu(In,Ga)(S,Se)₂ absorber. In addition further quality control tools like X-ray fluorescence analysis and Raman spectroscopy for stoichiometry monitoring, photoluminescence lifetime mapping and thermographic imaging have been developed in order to improve large area uniformity and reproducibility.

Some first full sized modules from the new pilot line look very promising: Aperture area efficiencies of up to 13.1% for monolithic thin film circuits on 0.54 m² and a module power of 65 W represent an international champion value for large are thin film solar modules.