ALBERT

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 188〈/p〉 〈p〉Author(s): Naser Abdi, Yaser Abdi, Zahra Alemipour〈/p〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 188〈/p〉 〈p〉Author(s): Smajil Halilovic, Jamie M. Bright, Wiebke Herzberg, Sven Killinger〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Knowledge of horizontal solar irradiance is crucial for the nowcasting and forecasting of generated photovoltaic (PV) power. High quality irradiance measurement devices, however, are typically not collocated with PV systems. The lack of measurements can be compensated by numerical weather models or satellite-derived products, but they provide only limited temporal and spatial resolutions. Another possibility is to directly use PV systems as irradiance sensors, since the measured PV power is a good indicator of incoming solar irradiance. The challenging part in this procedure is the computation of the global horizontal irradiance 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si233.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi〉G〈/mi〉〈/mrow〉〈mrow〉〈mi〉h〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 from the global tilted irradiance 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si234.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi〉G〈/mi〉〈/mrow〉〈mrow〉〈mi〉c〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉, because a combination of decomposition and transposition models is not analytically invertible. Hence, the majority of existing solutions to this problem are numerical procedures. In this paper, an analytical approach to compute 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si235.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi〉G〈/mi〉〈/mrow〉〈mrow〉〈mi〉h〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 from 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si236.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi〉G〈/mi〉〈/mrow〉〈mrow〉〈mi〉c〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 is presented. The comparison of the proposed approach with one of the existing iterative (numerical) approaches shows promising results. When applied to 1-min data at four different locations, the new approach outperforms the iterative procedure by up to 9% in terms of the relative root mean square error (rRMSE) for east/west module’s orientations, and performs slightly better with the south orientation. Moreover, the new approach provides results in less than 1 s, whereas the iterative procedure requires more than 20 min for a one year of data. An open source R-script of the new approach is also publicly available and provided as supplementary material.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 188〈/p〉 〈p〉Author(s): Dazhi Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Previously in “SolarData: An R package for easy access of publicly available solar datasets” [Sol. Energy 171 (2017) A3–A12], the R package 〈code〉SolarData〈/code〉 was built for easy access of five publicly available solar datasets. In this update, code for reading data from the Baseline Surface Radiation Network (BSRN), the largest research-grade solar radiation monitoring network, is added to the package. BSRN comprises 66 stations (as of 2019-02) around the globe, which collect 1-min or 3-min radiation data since 1992. These data are stored in the so-called “station-to-archive” files, each containing records from one month and one station, and can be downloaded via ftp. The functions in 〈code〉SolarData v1.1〈/code〉 directly interact with these station-to-archive files, without using the BSRN-Toolbox. It should however be noted that 〈code〉SolarData〈/code〉 is not a replacement of BSRN-Toolbox. Instead, it gives R users improved accessibility and freedom in BSRN data manipulation. Like the previous release, all contents herein described are made available on GitHub.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 188〈/p〉 〈p〉Author(s): B. Sri Revathi, Prabhakar Mahalingam, Francisco Gonzalez-Longatt〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, a novel non-isolated DC-DC converter topology is proposed for solar photovoltaic (PV) application. The proposed converter is constructed from an interleaved boost converter (IBC) to reduce the input current ripple. Voltage gain is extended by (i) using voltage lift technique, (ii) replacing the conventional inductors of the IBC by coupled inductors (CIs) with appropriate turns ratio and (iii) connecting a voltage multiplier cell (VMC) across the secondary windings of the CIs. As the voltage gain is extended mainly at the secondary side of the CIs, the switches are subjected to low voltage stress which is only 12.63% of the output voltage. The converter yields a high voltage conversion ratio of 15.83. Experimental results obtained from a 24 V/380 V, 225 W prototype converter operating at 91.6% efficiency serves as a proof of the presented concept which has been employed to achieve high voltage conversion ratio (15.83) with low input current ripple (20%).〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 188〈/p〉 〈p〉Author(s): Sebastian Müller, Federico Giovannetti, Rolf Reineke-Koch, Oliver Kastner, Bernd Hafner〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We present a comparative simulative study to evaluate the efficiency and stagnation behavior of commercially available absorber coatings for solar thermal flat-plate collectors. A market survey has revealed different absorber coatings, which exhibit solar absorptances of α 〉 90% and thermal emittances ε of 5–90%. All these coatings can be classified as wet-chemically electroplated coatings on the basis of black chrome, highly selective sputtered PVD coatings, solar paints and novel thermochromic coatings. We calculated the annual solar collector energy output by means of collector simulations with the tool ScenoCalc and compared the collector efficiency of several absorber coatings. We have carried out TRNSYS simulations both with systems for solar domestic hot water preparation and solar-assisted space heating. In a solar domestic hot water system with a daily tapping volume of 100 L we report an increase in the auxiliary energy demand of up to 6% with black chrome, 7% with thermochromic and 21% with solar paint coatings compared to sputtered PVD coatings. In a solar combisystem the increase in the auxiliary energy demand does not exceed 1.4% for thermochromic and black chrome coatings and 6.1% for solar paints. The stagnation period can be reduced from 178 h per year (PVD coatings) to 118 h, 62 h and 11 h for black chrome, thermochromic and solar paint coatings, respectively. The maximum absorber temperatures decrease from 175 °C (PVD coatings) to 165 °C for black chrome, 145 °C for thermochromic and 135 °C for solar paint coatings.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0038092X19306383-ga1.jpg" width="493" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 188〈/p〉 〈p〉Author(s): S. Marikkani, J. Vinoth Kumar, V. Muthuraj〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In past days, the occurrence of toxic heavy metal ions into the water and soil environment causes a major health risk to the living organisms. In this work, we mainly focused on the photoreduction of hexavalent chromium (Cr〈sup〉6+〈/sup〉) using novel sponge-like Fe〈sub〉2〈/sub〉V〈sub〉4〈/sub〉O〈sub〉13〈/sub〉 photocatalyst under visible light irradiation. The sponge-like Fe〈sub〉2〈/sub〉V〈sub〉4〈/sub〉O〈sub〉13〈/sub〉 was tailored through hydrothermal process using ferric chloride and sodium metavanadate precursors without the addition of any templates. The surface morphology, elemental analysis and various physical properties are characterized by numerous spectroscopic techniques. Interestingly, the sponge-like Fe〈sub〉2〈/sub〉V〈sub〉4〈/sub〉O〈sub〉13〈/sub〉 demonstrated proficient photocatalytic performances towards the reduction of Cr〈sup〉6+〈/sup〉 into Cr〈sup〉3+〈/sup〉. The obtained UV–visible spectroscopy results portrayed that sponge-like Fe〈sub〉2〈/sub〉V〈sub〉4〈/sub〉O〈sub〉13〈/sub〉 could reduce above of Cr〈sup〉6+〈/sup〉 solution within 40 min. The effect of operational reaction parameters such as catalyst dosage, initial Cr〈sup〉6+〈/sup〉 concentration and pH of the solution was optimized. Moreover, the sponge-like Fe〈sub〉2〈/sub〉V〈sub〉4〈/sub〉O〈sub〉13〈/sub〉 holds very good stability even after five consecutive cycles. This study could open new insights for the design novel nanostructured binary metal oxides for environmental applications.〈/p〉〈/div〉 〈/div〉