Some Remarks about the Deployment of Floating PV Systems in Brazil

Floating photovoltaic systems installed in water bodies such as natural lakes or dams reservoirs, have attracted increased worldwide attention since 2011 and have already been deployed in several countries, including Japan, South Korea and USA. In Brazil, pilot-projects were announced in the reservoirs of hydroelectric power plants of Balbina （State of Amazonas） and Sobradinho （State of Bahia）. Several advantages, not necessarily valid in Brazil, are mentioned for deploying this kind of technology, such as an increase in energy generation, reduction of water losses through evaporation, low environmental impact, no occupation of land etc. In this article, several of these allegations are analyzed preliminarily under the Brazilian point of view, and relevant considerations are presented. It is concluded that the technical and economic advantages of floating photovoltaic systems are not yet clear in Brazil and that pilot projects, such as those under way, should be used to clarify several important aspects related to them.

Three-Phase Optimal Power Flow for Study of PV Plant Distributed Impact on Distribution Systems

This paper presents a TOPF （three-phase optimal power flow） model that represents photovoltaic systems. The PV plant is modeled in the TOPF as active and reactive power source. Reactive power can be generated or absorbed using the available capacity and the adjustable power factor of the inverter. The reduction of unbalance voltage and losses in the distribution systems is obtained by actions of reactive power control of the inverter. The TOPF is formulated by current balance equations and the PV systems are modeled via an equivalent circuit. The primal-dual interior point method is used to obtain the optimal operating points for the systems for different scenarios of solar irradiance and temperature, thus providing a detailed view of the impact of photovoltaic distributed generation.

Photolumincscent Properties of Polyacetylenes Carbazole

The optical properties of one mono-substituted polyacetylene and two di-substituted polyacetylenes have been investigated. Each of the substituted polyacetylenes bears a carbazole unit in the side chain. In spite of the differences in their molecular structures, the dilute solutions(about 1×10-6 M) of these substituted polyacetylenes exhibit the same absorptions and deep-blue emissions(about 360 nm). Interestingly, the absorption and emission spectra of these substituted polyacetylenes are similar to those of the small molecule carbazole. As the concentration of the substituted polyacetylenes increases to about 1×10-6 M, we have detected intense blue emissions at about 475 nm. Our results indicate that the absorption, the deep-blue emission(about 360 nm) and the intense blue emission(about 475 nm) originate from the carbazole chromophores in the side chain.

Facile synthesis of porous Pd nanoflowers with excellent catalytic activity towards CO oxidation

Microorganism-mediated, hexadecyltrimethylammonium chloride （CTAC）-directed （MCD） method was employed in this work to synthesize Pd nanoflowers （PdNFs）. Proper Pichia postoris cells （PPCs） dosage, ascorbic acid （AA）, Pd（N03）2 and CrAC concentrations were essential for the growth of the PdNFs. The size of the as- synthesized PdNFs could be tuned by adjusting the amount of Pal（N03）2 solution and dosage of PPCs used. Characterization techniques such as X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy were used to verify the nature of the PdNFs. Finally the PdNF/PPC nanocomposites were immobilized onto TiO2 supports to obtain bio-PdNF/Ti02 catalysts which showed excellent catalytic activity for CO oxidation, obtaining 100%; conversion at 100 ℃ and remaining stable over a period of 52 h of reaction time. @ 2015 The Chemical Industry and Engineering Sodety of China, and Chemical Industry Press. All rights reserved.

Potential of Photovoltaic Industry in Egypt

PV （photovoltaic） market is dominated by Europe, especially Germany and Spain. However, the PV industry leaders recently exist in Asia. The huge market growth require industry growth, but with competitive cost. The electricity shortage in Egypt makes transferring to photovoltaic technology necessary, especially with the high solar radiation. The only reason why grid parity is not yet reached in Egypt is the elevated subsidiary of conventional electricity. If this subsidy is transformed to incentives for using and manufacturing solar cells, the situation will vary. This article shows that transferring PV industry to Egypt has a potential of cost saving of 5.7%, which could be translated either into competitive price or higher return on investment. This work is not a feasibility study. However, based on the cost structure of each phase in the PV industry value chain, the benefit （5.7% cost reduction potential） of transferring the industry to Egypt is worthy to accomplish the needed feasibility study.

Commissioning Status of NSLS-II Vacuum Control System

The NSLS-II （National Synchrotron Light Source II） is a state-of-the-art 3 GeV third generation light source currently under integrated testing and commissioning at Brook_haven National Laboratory. The vacuum systems are monitored by vacuum gauges and ion pump current. The gate valves are controlled by PLC （programmable logic controllers） using voting scheme. EPICS （Experimental Physics and Industrial Control System） application codes provide the high level monitoring and control through the input-output controllers. This paper will discuss the commissioning status of the various aspects of vacuum control system.

Design of a Mobile Photovoltaic Module System for Demonstration and Experimentation

In Mexico, owing to solar radiation conditions, there is great potential for PV （photovoltaic） systems. Besides, since 2007, the solar electricity interconnection agreement became official which allowed for an important growth of the photovoltaic industry. Due to the important development of the PV industry, there is a need for engineers trained to design, install, and evaluate PV systems The UAEMEX （autonomous university of the state of Mexico） offers a new bachelor degree of engineering program which dedicated to the development of sustainable energy systems. This kind of programs requires special equipment for experimentation and practice Specialists at UAEMEX also detected the need for a system to evaluate and demonstrate the application of PV modules, but they also found that most of the systems on the market are very expensive and unable to evaluate different arrangements. The goal of this paper is to present the design of a mobile system to evaluate PV modules and arrangements. This system is useful, not only for demonstration practices, but also for experimentation with different materials and types of PV panels. The design allows for two or four PV modules to be assembled in different positions and inclinations. The prototype is equipped with a data acquisition system that will be used to obtain the PV module performance curves. It will also be used to evaluate the atmospheric, interference and shadow effects on these modules. This prototype will be used to complement the practice learning of solar PV systems, but also to demonstrate the use of PV modules. The prototype is being design and constructed by a group of mechanical and electronic engineering students and this fact will be useful to meet the needs of basic science, math, and engineering teaching objectives in an integrated and hands-on way project. The essential features of system are described. A comparative analysis of the systems on the market is carried out. Also presented are the learning advantages for the students involved in the design and construction of this kind of systems, as well as a summary of practices that may be performed with the equipment.

Distributed Solar PV System for Industrial Application

The paper presents the design and field test of a distributed solar PV system for industrial application （DGPVi）. DGPVi utilizes HyPV （hybrid PV） system which generates solar power for self-consumption in lighting and air conditioning in a production line of a factory when solar energy is available. It does not feed the excess PV power to the grid. HyPV will be switched to grid power supply when solar energy is not available. A 3 kWp DGPVi is installed in a factory for field demonstration. The test results show that the solar PV power generated can be utilized immediately. The solar energy generation efficiency （kWh/day per kWp PV installation） of DGPVi is close to that of grid-tied PV system without self-consumption and battery storage. The yearly return on investment of DGPVi is 2.0% at the present installation cost or 3.3% at further cost-down cost. The payback time will be 14.3 years at the present installation cost or 12.1 years at cost-down cost. The present study verifies the economic feasibility of DGPVi.

植物工厂能做下去吗?

植物工厂最早诞生于丹麦,却在日本受到了热烈追捧。日本将解决人多地少、社会人口老龄化的希望寄托在植物工厂上。尤其是2011年后,经历了3·11海啸和福岛核电站事故,日本政府投入大量资金,希望通过鼓励建植物工厂为国民解决食物的供给和安全问题。一时间,植物工厂成为了创业风口,东芝、松下、富士通等光电业巨头也纷纷入局。但几年时间过去了,植物工厂在日本的发展却不尽如人意。

Wafer scale direct-write of Ge and Si nanostructures with conducting stamps and a modified mask aligner

The broad availability of high throughput nanostructure fabrication is essential for advancement in nanoscale science. Large-scale manufacturing developed by the semiconductor industry is often too resource-intensive for medium scale laboratory prototyping. We demonstrate the inexpensive wafer scale direct- write of Ge and Si nanostructures with a 4-inch mask aligner retrofitted with a conducting microstructured stamp. A bias applied between the stamp and an underlying silicon substrate results in the reaction of diphenylgermane and diphenylsilane precursors at the stamp--substrate interface to yield the direct- write of Ge and Si nanostructures in determined locations. With the increasing number of outdated mask aligners available from the semiconductor industry and an extensive library of liquid precursors, this strategy provides facile, inexpensive, wafer scale semiconductor direct-write for applications such as electronics, photonics, and photovoltaics.

China’s progress of perovskite solar cells in 2019

Perovskite solar cells(PSCs)have attracted worldwide attention due to their high efficiency and low manufacturing cost.As the largest supplier of photovoltaic modules,China has made huge endeavors in the research on PSCs.In 2019,Chinese research groups were still holding the top position for paper publications in the world.Both the efficiency and the stability of the device have been steadily increasing,pushing forward the commercialization of PSCs step by step.This review summarizes the highlights of China’s PSC research progress in 2019 and briefly introduces the development of PSC modules in industry.