ALBERT

Beschreibung: 〈p〉Publication date: 1 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 198〈/p〉 〈p〉Author(s): Halil Atalay〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, an evaluation of energy and economic analysis of two different energy storage systems for the drying process was presented. These systems were the packed bed (PBTES) and phase change material (PCM) thermal energy storage systems, respectively. Pebble stones were utilized as energy storage material in PBTES, while paraffin wax with a melting temperature of 55–60 °C was used in PCM. The main objective of this study was to compare two energy storage materials whose physical and chemical properties were completely different, in terms of performance and costs and to determine the ideal energy storage medium for the solar energy-assisted drying process. For this purpose, two different energy storage mediums of similar capacity were developed and examined experimentally. When the systems were investigated in terms of energy analysis, it was determined that the maximum thermal energy stored during the charging period was 52.59 MJ and 49.52 MJ for PBTES and PCM, respectively. With this energy stored during the discharge period, average 5 mm thick lemon slices were dried and the drying process lasted an average of 6.27 h in PBTES and 6.23 h in the PCM. During the drying process, the moisture content of the lemon slices was reduced from 94.8% to 10% on wet basis. As a result of the experimental studies, the average energy efficiencies were detected as 68.2% and 68.55% for PBTES and PCM, respectively. When the systems were considered economically, it was observed that PBTES had a 10.47% lower initial investment cost compared to PCM.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 198〈/p〉 〈p〉Author(s): Donggen Peng, Zhuo Cao, Yuting Fu, Shuangling Li, Zexuan Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, a self-preheated solar collector/regenerator (C/R) is proposed to conquer the anti-regeneration phenomenon of traditional solar C/R in order to increase its regeneration efficiency. Through numerical simulation, the applicability of the self-preheated C/R in Northern and Southern cities of China and parameter optimization as well as the performance comparisons with the traditional C/R are conducted. The research results show the self-preheated C/R has good applicability for the 24 cities chosen in China, but the length of collector section is selected in the optimum ranges. The optimal proportion of collector length in the southern China is in the range of 0.4–0.55 while it focusing on 0.35–0.5 in the northern China. In the optimization of parameters, the best flow-rates of air and solution for the unit area of C/R fall into the ranges of 50–100 kg/(m〈sup〉2〈/sup〉·h) and 3–6 kg/(m〈sup〉2〈/sup〉·h) respectively, and the height of C/R glazing should be maintained at 0.04–0.06 m for higher regeneration efficiency of the device. By comparing to the performance of traditional C/R, the self-preheated solar C/R has greater superiority at higher ambient relative humidity, lower solution temperature and higher solution concentration as well as lower solar radiation intensity. The increased extent can reach as much as 22% at 〈em〉ξ〈/em〉〈sub〉in〈/sub〉 = 0.4 kg/kg. The total length of self-preheated C/R has an optimal value on the performance of device. All these results can provide guidance for performance analysis and application of the novel solar collector/regenerator.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 198〈/p〉 〈p〉Author(s): Xiaojuan Liu, Pan Ding, Zhihua Yuan, Hui Tian, Youzhou Jiao, Samira Agbolaghi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Morphological, electrochemical, and photovoltaic stabilities of the poly[benzodithiophene-bis(decyltetradecyl-thien) naphthothiadiazole] (PBDT-DTNT):phenyl-C61-butyric acid methyl ester (PC71BM) solar cells were promoted by the pre-designed supramolecules on the basis of reduced graphene oxide (rGO) nanosheets. Nanostructures consisted of the pristine rGO, grafted-rGO/PBDT-DTNT, rGO-polythiophene (GPTh) electrospun nanofiber, grafted-rGO/PBDT-DTNT electrospun nanofiber and rGO/PBDT-DTNT samples. The reduction in photovoltaic characteristics during air aging was the steepest for the unmodified PBDT-DTNT:PC71BM solar cells. From rGO based photovoltaics towards the rGO/PBDT-DTNT modified ones possessing the well-patterned PBDT-DTNT nanofibers, the slopes of graphs decreased. The most stabilized devices were fabricated on the basis of PBDT-DTNT:PC71BM:rGO/PBDT-DTNT active layers (power conversion efficiency (PCE) from 6.09% for upon-fabricated to 4.87% for 1 month aged systems) for having the most red-shifted and intensified absorbance, the largest phase separation, the lowest impedance responses and the highest photovoltaic characteristics during 1 month air aging (short circuit current density (J〈sub〉sc〈/sub〉) of 12.09 mA/cm〈sup〉2〈/sup〉, fill factor (FF) of 63%, open circuit voltage (V〈sub〉oc〈/sub〉) of 0.64 V, hole mobility (µ〈sub〉h〈/sub〉) of 5.3 × 10〈sup〉–5〈/sup〉 cm〈sup〉2〈/sup〉/V s, electron mobility (µ〈sub〉e〈/sub〉) of 7.9 × 10〈sup〉–4〈/sup〉 cm〈sup〉2〈/sup〉/V s, charge transfer resistance (R〈sub〉tr〈/sub〉) of 431 Ω cm〈sup〉2〈/sup〉 and PCE of 4.87%). The GPTh/PBDT-DTNT/PC71BM (J〈sub〉sc〈/sub〉 = 10.31 mA/cm〈sup〉2〈/sup〉, FF = 49%, V〈sub〉oc〈/sub〉 = 0.55 V, R〈sub〉tr〈/sub〉 = 796 Ω cm〈sup〉2〈/sup〉 and PCE = 2.78%) and grafted-rGO/PBDT-DTNT/PBDT-DTNT (J〈sub〉sc〈/sub〉 = 10.98 mA/cm〈sup〉2〈/sup〉, FF = 56%, V〈sub〉oc〈/sub〉 = 0.60 V, R〈sub〉tr〈/sub〉 = 539 Ω cm〈sup〉2〈/sup〉 and PCE = 3.69%) electrospun nanofibers also imparted the stabilization of devices within 1 month.〈/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-S0038092X20300396-ga1.jpg" width="286" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 198〈/p〉 〈p〉Author(s): Kęstutis Valančius, Rūta Mikučionienė〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The paper analyses the energy and technical possibilities of installing systems that use renewable energy sources (solar energy) to renovate soviet type apartment buildings. The aim of the analysis is to study the possibilities of using solar energy systems to renovate apartment buildings (five-storey, nine-storey and sixteen-storey), which are built in Lithuania, provide detailed conclusions about the energy and engineering aspects of such systems. The authors also intend to determine the optimal technological combinations and solutions that would allow achieving maximum energy benefits (solar collectors for domestic hot water preparation and photovoltaic panels for electricity use). For the research computer simulation tools 〈em〉EnergyPRO〈/em〉 and PV*SOL Premium were selected. Actual collected heat and electricity consumption data is also used for the analysis.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 198〈/p〉 〈p〉Author(s): Hwa-Dong Liu, Chang-Hua Lin, Kai-Jun Pai, Chien-Ming Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study realises a new solar-power generation system that can complete the global maximum power point tracking (GMPPT) control under uniform irradiation and partial shading conditions (UIC and PSC, respectively). The microcontroller unit of the proposed system calculates the 〈em〉I〈/em〉〈sub〉GMPP〈/sub〉 of the photovoltaic (PV) module to accurately execute GMPPT on the basis of the PV module current (〈em〉I〈/em〉〈sub〉pv〈/sub〉), power (〈em〉P〈/em〉〈sub〉pv〈/sub〉) and temperature trend line 〈em〉slope〈/em〉 (〈em〉dI〈/em〉〈sub〉pv〈/sub〉〈em〉/dP〈/em〉〈sub〉pv〈/sub〉). The microcontroller unit can then confirm whether the PV module suffers from shading according to the 〈em〉slope〈/em〉 (〈em〉dI〈/em〉〈sub〉pv〈/sub〉〈em〉/dP〈/em〉〈sub〉pv〈/sub〉) and immediately executes the PSC mode control strategy to calculate the 〈em〉V〈/em〉〈sub〉GMPP〈/sub〉 of the PV module, thereby accurately tracking the GMPP. Further, the proposed algorithm is compared with the particle swarm optimization (PSO) method, traditional hill-climbing (HC), and perturbation and observation (P&Q) algorithms for MATLAB simulation and actual measurement. These four algorithms firstly use MATLAB to simulate the dynamic response of the solar irradiance level from 1000 W/m〈sup〉2〈/sup〉 to 500 W/m〈sup〉2〈/sup〉. Then the measured separately under UIC of 1000 W/m〈sup〉2〈/sup〉, and measured under PSC of 500 W/m〈sup〉2〈/sup〉 and 1000 W/m〈sup〉2〈/sup〉, respectively. Finally, all the simulations and experimental results confirm that the proposed algorithm has better GMPPT performance and convergence time than the PSO, the traditional HC, and P&O techniques.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 198〈/p〉 〈p〉Author(s): Viivi Kallio-Myers, Aku Riihelä, Panu Lahtinen, Anders Lindfors〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Global horizontal irradiance (GHI) estimates and forecasts are necessary for the efficient use of a naturally fluctuating energy source like solar energy. However, few forecasting methods exist for high latitudes. In this study we present the development and validation of a satellite-based GHI forecast for southern Finland, called Solis-Heliosat. The forecast is formed by combining information from the clear sky (CS) model Pvlib Solis with consecutive geostationary weather satellite imagery, using the Heliosat method. Forecasts are produced up to 4 h with a 15-min temporal resolution. The CS model, the satellite-based all-sky estimate, and the GHI forecast have been compared and validated against other methods and in situ GHI measurements. An additional comparison was made for two datasets representing a changing cloud environment.〈/p〉 〈p〉The CS model estimates had an average rMBE (relative Mean Bias Error) of −6% to 1% and a rRMSE (relative Root Mean Square Error) of 6–10%. For the all-sky estimates the rMBE was −4% to −2%, and rRMSE 2–33%. With increasing forecast time the Solis-Heliosat rMBE descends to −9% and rRMSE reaches 50% at 4 h. Solis-Heliosat performs better than the persistence forecasts in most cases, particularly in a changing cloud environment.〈/p〉 〈p〉Our study indicates the use of satellite-based forecasts as a viable tool for forecasting GHI for the solar energy industry also in the high latitudes. In high latitudes geostationary satellite-based methods are at their limit; however, the information they can provide will enable efficient solar energy production.〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 198〈/p〉 〈p〉Author(s): Islam M. Abdellah, Ahmed El-Shafei〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Novel metal free organic dyes coded 〈strong〉TET(RA)〈sub〉4〈/sub〉, TET(CA)〈sub〉4〈/sub〉,〈/strong〉 and 〈strong〉TET(QA)〈sub〉4〈/sub〉〈/strong〉 were designed, synthesized, and characterized as effective sensitizers for dye sensitized solar cells (DSSCs). These new push-pull sensitizers used a strong electron donor consisting of 3,4-ethylenedioxythiophene and two triphenylamine molecules connected together to form a TPA-EDOT-TPA (〈strong〉TET〈/strong〉) motif, which is directly connected to tetra anchoring groups (A) without any π-spacers to construct A〈sub〉2〈/sub〉-D-D-D-A〈sub〉2〈/sub〉 architecture, three different anchoring series, 〈em〉viz.〈/em〉 rhodanine-3-acetic acid 〈strong〉(RA)〈/strong〉, cyanoacetic acid 〈strong〉(CA)〈/strong〉, and 2-methyl quinoline-6-carboxylic acid 〈strong〉(QA)〈/strong〉 were employed to investigate the influence of anchoring moieties on the electrochemical, thermodynamic, kinetics, and photovoltaic efficiency of DSSCs. The DSSCs devices showed a maximum overall power conversion efficiency (PCE) = 5.13%, short-circuit current density (〈em〉J〈sub〉SC〈/sub〉〈/em〉) 〈em〉=〈/em〉 12.71 mA.cm〈sup〉−2〈/sup〉, open circuit voltage (〈em〉V〈sub〉OC〈/sub〉〈/em〉) = 0.62 V, and fill factor (〈em〉FF〈/em〉) = 65.36% with a maximum incident photon conversion efficiency (IPCE) = 75% for 〈strong〉TET(QA)〈sub〉4〈/sub〉〈/strong〉. The optical and electrochemical studies showed that 〈strong〉TET(QC)〈sub〉4〈/sub〉〈/strong〉 achieved higher electron injection free energy (ΔG°〈sub〉inj〈/sub〉) into CB edge of TiO〈sub〉2〈/sub〉 as well as high recombination resistance (R〈sub〉rec〈/sub〉) compared to 〈strong〉TET(RA)〈sub〉4〈/sub〉,〈/strong〉 and 〈strong〉TET(CA)〈sub〉4〈/sub〉,〈/strong〉 which explains the outstanding charge separation and superior power conversion efficiency (PCE) of 〈strong〉TET(QC)〈sub〉4〈/sub〉〈/strong〉 possessing quinoline-6-carboxylic acid (QC) anchoring group. Molecular modeling calculations using DFT and TD-DFT showed effective charge separation, where HOMO is delocalized over the donor scaffold (TPA-EDOT-TPA), and the LUMO is delocalized over only two anchoring groups on the same side of the donor system, which provides strong HOMO-LUMO overlap as well as intimate electronic coupling with TiO〈sub〉2〈/sub〉 nanoparticle surface for electron injection. Further, the calculated values of the energy gaps (〈em〉E〈sub〉0-0〈/sub〉〈/em〉) and ground/excited stated oxidation potentials were in perfect agreement with the experimental results.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉It is showing the influence of anchoring groups on electron injection and photocurrent density in sensitizers based on A〈sub〉2〈/sub〉-D-D-D-A〈sub〉2〈/sub〉 architecture.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0038092X20300487-ga1.jpg" width="314" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 198〈/p〉 〈p〉Author(s): A. Bazgaou, H. Fatnassi, R. Bouharroud, F. Elame, K. Ezzaeri, L. Gourdo, A. Wifaya, H. Demrati, R. Tiskatine, A. Bekkaoui, A. Aharoune, L. Bouirden〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉During the winter period, in Mediterranean region, the storage and reuse of solar energy in thermal form is an important issue for heating greenhouses. In the present work, the performance of a combination of two systems i.e. rock-bed thermal energy storage and water filled passive solar, for heating canarian greenhouse was analyzed and discussed. The surplus thermal energy available inside the greenhouse was stored in the rock-bed and in the water during daytime for use during cold periods. An experimental study was carried out in two Canarian-type greenhouses, the first is equipped with the combined heating system and the second without. Results show that the combined heating system can improve the nocturnal inside air temperature, during the winter period, by 3–5 °C during clear days and by 2–3 °C in cloudy/rainy days with less fluctuations. A reduction of 10–15% in the air relative humidity was observed in the heated greenhouse during the night. This heating system also improves the substrate temperature during the night by 4 °C on cloudless days and 3 °C on cloudy/rainy days. A very good growth of plants and an increase of 49% of tomato yield has been noted in the heated greenhouse. The thermal energy restored by this system covers a large part of the greenhouse heating requirements. It was also noted that the presence of this heating system lead to a decrease in the development the population of 〈em〉Tuta absoluta〈/em〉 in the heated greenhouse. An economic analysis revealed that this system is very profitable and could generate profits for farmers.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 198〈/p〉 〈p〉Author(s): Chang Li, Jiayou Tao, Zhijun Zou, Gaohua Liao, Fen Li, Jifei Wang, Xiaoxiang Sun, Jian Ni, Jianjun Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ternary blend polymer solar cells (TPSCs) comprising one donor and two fullerene acceptors is efficient method for improving the power conversion efficiency (〈em〉PCE〈/em〉). In this paper, the PTB7-Th-based TPSCs which is incorporating PC〈sub〉70〈/sub〉BM and PC〈sub〉60〈/sub〉BM as mixed acceptors are fabricated and investigated. Impressively, the remarkable self-assembled nano-ridged (SANR) structures are discovered in the active layer with the weight ratio of 50% PC〈sub〉60〈/sub〉BM in fullerenes. Thanks to the enlarged interface area, enhanced light absorption and balanced carrier transport, the PTB7-Th:PC〈sub〉70〈/sub〉BM:PC〈sub〉60〈/sub〉BM TPSCs with the SANR active layer gives an optimal 〈em〉PCE〈/em〉 of 9.68%. In addition, it is worth emphasizing that by combining the textured-ZnO with the SANR active layer, a double ridge superimposed system (DRSS) with broad spectrum light trapping characteristic is constructed, which can further enhance the light absorption of the devices. Finally, benefiting from the further increase in short circuit current density (〈em〉J〈sub〉sc〈/sub〉〈/em〉), the PTB7-Th:PC〈sub〉70〈/sub〉BM:PC〈sub〉60〈/sub〉BM TPSCs with the DRSS gives an optimal 〈em〉PCE〈/em〉 of 10.68%. This work provides a feasible ternary strategy to increase the devices performances and is proved be a simple and efficient strategy for fabricating PTB7-Th:PC〈sub〉70〈/sub〉BM:PC〈sub〉60〈/sub〉BM TPSCs with SANR active layer.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉In this paper, we first report the PTB7-Th:PC〈sub〉70〈/sub〉BM:PC〈sub〉60〈/sub〉BM TPSCs whose active layer is capable of forming the self-assembled nano-ridged (SANR) structures, and the SANR-active layer coupled with the textured-ZnO is able to form the double ridge superimposed system with broad spectrum light trapping characteristic, offering a promising way for the efficiency enhancement of the devices.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0038092X20300529-ga1.jpg" width="389" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 198〈/p〉 〈p〉Author(s): Ronald Muhumuza, Aggelos Zacharopoulos, Jayanta Deb Mondol, Mervyn Smyth, Adrian Pugsley, Jade McGee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper reports the development and application of a new practical photovoltaic (PV) cells based device to measure the solar radiation flux produced by non-imaging Compound Parabolic Concentrators (CPCs) on cylindrical absorbers. The flexible experimental device comprises 12 discrete miniature PV panels that measure solar radiation on the surface of a cylindrical absorber. The device has been used to evaluate the performance of an asymmetric CPC system and results validated with a computer-based Ray Tracing Model. The study attained significant agreement between outdoor results of the experimental device and results of the ray tracing simulation with a difference of 〈9% in optical efficiencies. The non-imaging reflector illuminates a targeted section of the absorber of a horizontal east-west thermal diode Integrated Collector Storage Solar Water Heater. During outdoor testing, the experiments indicated a local concentration ratio reaching 1.4 suns on the targeted section of the absorber vessel surface for incidence angles 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si8.svg"〉〈mrow〉〈mo linebreak="badbreak" linebreakstyle="after"〉-〈/mo〉〈msup〉〈mn〉30〈/mn〉〈mo〉°〈/mo〉〈/msup〉〈mo〉≤〈/mo〉〈msub〉〈mi〉θ〈/mi〉〈mi〉i〈/mi〉〈/msub〉〈mo〉≤〈/mo〉〈msup〉〈mn〉30〈/mn〉〈mo〉°〈/mo〉〈/msup〉〈/mrow〉〈/math〉, confirming technical suitability of the asymmetric CPC for deployment in locations at equatorial latitudes.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 198〈/p〉 〈p〉Author(s): Yousef N. Dabwan, Gang Pei, Guangtao Gao, Junsheng Feng, Jing Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This article presents the results of a thermodynamic-economic-environmental analysis of integrating linear Fresnel reflector (LFR) with a tri-generation system. The optimal integrated solar field size has been identified and the pertinent reduction in CO〈sub〉2〈/sub〉 emissions due to solar integration is estimated. For the considered tri-generation plant (that is required to produce 110 MWe of electricity from steam turbines, 45461 m〈sup〉3〈/sup〉/day of freshwater and 2300 kg/s of chilled water), the study revealed that the optimal configuration is the integration of 83.6 hectares of LFR solar field with the tri-generation plant of 130 MWe, which gives a levelized electricity cost of 6.37 USȻ/kWh with 96.40 k-tonne reduction of the annual CO〈sub〉2〈/sub〉 emission. The study also revealed that the integration of LFR technology with a conventional tri-generation system (TGS) in high insolation regions has more economic feasibility compared to equivalent TGS integrated with CO〈sub〉2〈/sub〉 capturing technology while achieving the same emissions reduction result.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 198〈/p〉 〈p〉Author(s): Muath Bani Salim, Reza Nekovei, R. Jeyakumar〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Tandem organic photovoltaic (TOPV) cell is one of the technologies to harvest more solar power by staking two or more OPV devices on top of each other. Recently, the highest power conversion efficiency (PCE) ever achieved was 17.3%. Herein, this paper simulates the response of 676‬ different TOPV devices that consists front and back OPV cells. For this purpose, this paper uses the best 26 single-cell OPV devices to form the TOPV front and back cells combinations. The results show that there are some new TOPVs that can exceed 17.3% efficiency limit for TOPV. Also, in this work thickness optimization was performed for these new TOPV devices with an objective of efficiency maximization. As a result, using PBDTS-TDZ: ITIC in the front cells and PTB7-Th: O6T-4F:PC71BM in the back cell gives 18.6% efficiency. Likewise, the TOPV of PBDB-T-2F:TfIF-4FIC in the front cell with PTB7-Th:O6T-4F:PC71BM in the back cell gives 18.06% efficiency.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 198〈/p〉 〈p〉Author(s): Yilin Li, Yujian Sun, Yongcao Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this report, we introduced subwavelength sanding treatment to boost the cost-effectiveness of luminescent solar concentrators (LSCs). It was proven the hypothesis that sanding the device surface to roughness (〈em〉R〈sub〉q〈/sub〉〈/em〉 = 22–105-nm) much smaller than the wavelength of sunlight (〈em〉λ〈/em〉 = 280–4000 nm) would improve the device performance due to much higher scattering gain than scattering loss. Experimental results showed that the sanded devices exhibited power conversion efficiency (〈em〉η〈sub〉LSC〈/sub〉〈/em〉) and power concentration ratio (〈em〉C〈/em〉) enhanced by at least 44% and could have the doping concentration of the luminophores significantly reduced by 87.5%. Measurement on the waveguide edge emission revealed that the performance enhancement was attributed to the utilization of the long-wavelength (〈em〉λ〈/em〉 〉 800 nm) photons. Monte Carlo ray tracing simulation signified that the subwavelength sanding treatment was also applicable to large-area devices with geometric gain (〈em〉G〈/em〉) up to 120 (9.29 m〈sup〉2〈/sup〉) and devices made of other luminophores. Cost-effectiveness analysis indicated a huge reduction by 45% in the price per watt (〈em〉PPW〈/em〉) for large-area commercial-sized (80 in. by 40 in.) LSCs. This study suggested that subwavelength sanding treatment was promising to bridge the gap between research and commercialization of the LSCs.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 198〈/p〉 〈p〉Author(s): Bilal Babar, Luigi Tommaso Luppino, Tobias Boström, Stian Normann Anfinsen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Datasets from meteorological reanalyses and retrievals from satellites are the available sources of large-scale information about solar radiation. However, both the reanalyses and the satellite-based estimates can be severely biased, especially in high latitude regions. In this study, surface solar irradiance estimates from the ECMWF Reanalysis 5 (ERA5) and the Cloud, Albedo, Radiation dataset Edition 2 (CLARA-A2) were used as input to a random forest regression (RFR) model to construct a novel dataset with higher accuracy and precision than the input datasets. For daily averages of global horizontal irradiance (GHI) at Norwegian sites, CLARA-A2 and ERA5 respectively produced a root mean squared deviation (RMSD) of 17.9 Wm〈sup〉−2〈/sup〉 and 27.1 Wm〈sup〉−2〈/sup〉, a mean absolute deviation (MAD) of 11.9 Wm〈sup〉−2〈/sup〉 and 17.5 Wm〈sup〉−2〈/sup〉, and a bias of −1.5 Wm〈sup〉−2〈/sup〉 and 4.3 Wm〈sup〉−2〈/sup〉. In contrast, the proposed regression model provided an RMSD of 16.2 Wm〈sup〉−2〈/sup〉, an MAD of 10.8 Wm〈sup〉−2〈/sup〉, and a bias of 0.0 Wm〈sup〉−2〈/sup〉. This shows that the RFR model is both accurate and precise, and significantly reduces both dispersion and bias in the new dataset with respect to the constituent sources. A sky-stratification analysis was performed and it was found that the proposed model provides better estimates under all sky conditions with particular improvements in intermediate-cloudy conditions. The proposed regression model was also tested on five Swedish locations and it was found to improve surface solar irradiance estimates to a similar degree as for the Norwegian locations, thus proving its consistency under similar climatic conditions.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Rajendra Bhatt, Ivan Kravchenko, Mool Gupta〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, we present the design, fabrication, optimization, and experimental results of a high-efficiency planar solar thermophotovoltaic (STPV) system utilizing a micro-textured absorber and a nanostructure multilayer metal-dielectric coated selective emitter fabricated on a tungsten (W) substrate. Light absorptance of more than 90% was achieved at visible and near-infrared wavelengths using the microtextured absorbing surface. The nanostructure selective emitter consists of two thin-film optical coatings of silicon nitride (Si〈sub〉3〈/sub〉N〈sub〉4〈/sub〉) and a layer of W in between to increase the surface emissivity in spectral regimes matching the quantum efficiency of the thermophotovoltaic (TPV) cells. Gallium antimonide (GaSb)-based TPV cells are used in our STPV design. The experiment was conducted at different operating temperatures using a high-power continuous wave laser diode stack as a simulated source of concentrated incident radiation. Our experimental setup measured a maximum electrical output power density of 1.71 W/cm〈sup〉2〈/sup〉 at 1676 K STPV temperature, and the overall power conversion efficiency of 8.4% after normalizing the output power density to the emitter area. This is the highest STPV system efficiency reported so far for any experimental STPV device. The incident optical laser power on the absorber side was 131 W. This is equivalent to a solar concentration factor of ~2100, which is within the practical limit and readily achievable with Fresnel lens setup.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Van-Duong Dao, Hai-Linh Thi Dang, Ngoc Hung Vu, Hong Ha Thi Vu, Nguyen Duc Hoa, Nguyen Van Hieu, Pham Anh Tuan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study focuses on the synthesis of nanoporous NiO nanosheets hybridized with PEDOT:PSS, Cdot and Pt nanoparticles and screening the catalytic activities for the regeneration of iodide ions from triiodide ions in liquid-junction photovoltaic devices. Due to a special hexagonal structure of NiO nanosheets, Pt nanoparticles and Cdot are easily immobilized on the surface and walled holes of NiO nanosheets with the size in the range of 2–5 nm. The electrochemical performances indicate the catalytic activity of counter electrodes (CEs) follows the sequence of NiO-Pt 〉 Pt sputtering 〉 NiO-Cdot 〉 NiO-PEDOT:PSS 〉 NiO. Thus, the photovoltaic performances provide the efficiency of 1.73, 5.51, 8.25 and 9.66% for cells with NiO, NiO-PEDOT:PSS, NiO-Cdot and NiO-Pt CEs, respectively, which are compared to the device using the Pt electrode (8.86%). The findings in this work are promising for developing highly efficient Pt-free catalyst materials for CEs of devices.〈/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-S0038092X20300451-ga1.jpg" width="449" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Min Zhang, Min Zeng, Huajie Chen, Lanyan Li, Bin Zhao, Songting Tan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Two A〈sub〉2〈/sub〉-D-A〈sub〉1〈/sub〉-D-A〈sub〉2〈/sub〉-type small molecule acceptors (SMAs), 〈strong〉DFB-dIDT〈/strong〉 and 〈strong〉BT-dIDT〈/strong〉 with 2,5-difluorobenzene (DFB) or benzothiadiazole (BT) as electron-withdrawing core (A〈sub〉1〈/sub〉) and a derivative of indanone as A〈sub〉2〈/sub〉 units, were prepared for applications in organic solar cells (OSCs). The results indicate that BT unit is more beneficial to forming multiple noncovalent conformational locks of N⋯S and N⋯H between BT and IDT unit than DFB in the core, so 〈strong〉BT-dIDT〈/strong〉 showed better molecular coplanarity, higher-lying HOMO energy level, more red-shifted spectrum, superior molar absorption coefficient (1.60 × 10〈sup〉5〈/sup〉 M〈sup〉−1〈/sup〉 cm〈sup〉−1〈/sup〉 at 696 nm), more complementary absorption spectrum with PBDB-T and better photovoltaic performance than 〈strong〉DFB-dIDT〈/strong〉. As a result, the BT-dIDT-based OSCs blending with PBDB-T exhibited higher power conversion efficiency (PCE) value of 10.52% with higher 〈em〉J〈/em〉〈sub〉sc〈/sub〉 of 18.59 mA cm〈sup〉−2〈/sup〉 than that of the 〈strong〉DFB-dIDT〈/strong〉-based devices (PCE of 6.71% with 〈em〉J〈/em〉〈sub〉sc〈/sub〉 of 15.58 mA cm〈sup〉−2〈/sup〉). These results demonstrate that the A〈sub〉2〈/sub〉-D-A〈sub〉1〈/sub〉-D-A〈sub〉2〈/sub〉-type SMAs incorporated with a suitable electron-deficient core are promising candidates for high performance OSCs.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Artúr Szilágyi, Gyula Gróf〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Balance-of-system components represent a growing share of environmental impacts in photovoltaic utility-scale solar energy systems. There are, however, no effective methods to carry out screening type life-cycle assessment during the planning phase of the power plant to minimize these impacts. This paper uses the European Commission’s novel product environmental footprint methodology to explore the life-cycle impacts of a case study in Hungary and applies two life-cycle models with different system boundaries and assumptions. The first model represents a full-fledged assessment with a detailed inventory, while the other, simplified model can be directly linked to the main plant design parameters. Our results show that: a) the production of photovoltaic modules account for around half of the total aggregated environmental impacts, b) compared to the Hungarian grid mix, the new power plant reduces the environmental footprint by 75%. It is also shown that the simplified model captures the overwhelming majority of impacts, thus, it is applicable during the eco-design of similar systems.〈/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-S0038092X20300360-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): S. Voswinckel, T. Mikolajick, V. Wesselak〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Copper Indium Gallium Diselenide (CIGS) shows a degradation due to a voltage between the solar cell and the ground potential, known from other solar cell technologies as well. This degradation is named potential induced degradation (PID). At the cell level, PID has been studied in laboratory experiments and can be traced back to sodium diffusion, which is accelerated by the mentioned voltage against ground potential. The applied potential will lead to a leakage current, which can serve as an indicator for PID.〈/p〉 〈p〉The question whether PID of CIGS thin film solar modules also occurs in real PV power plants inevitably arises. To solve this question the degradation behaviour will be analysed by accelerated aging tests. Furthermore, the influence of different leakage current pathways will be shown. The results of this study serve as a basis for modelling the lifetime of CIGS thin-film solar modules taking degradation due to PID into account.〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Tania Morabito, Salvatore Sau, Anna Chiara Tizzoni, Annarita Spadoni, Mauro Capocelli, Natale Corsaro, Cadia D'Ottavi, Silvia Licoccia, Tiziano Delise〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Chemical storage systems are a promising innovative route to overcome the issue of the solar irradiation storage, resulting as cost effective and with high energy density.〈/p〉 〈p〉A main problem with these kinds of materials is to design a synthesis method for preparing stable reactive structures, presenting at the same time a high volumetric charging/discharging enthalpy.〈/p〉 〈p〉At this purpose, a size controlled spinel was produced, characterized and investigated regarding its thermophysical and kinetics properties. The obtained powder presents an average diameter between 100 and 200 µm and an energy density of 133 J/g and an experimental test was carried out to verify the spinel morphology stability under thermal cycles.〈/p〉 〈p〉The specific heat is similar to other structured chemical storage system and makes the spinel feasible to be used also as sensible accumulation medium.〈/p〉 〈p〉Despite the relatively high particles size, and the expected small exposed reactive area, the charging, and especially discharging reaction rates resulted particularly favourable and comparable with the reported behaviour of micrometric powders.〈/p〉 〈p〉The particularly simple preparation method plus the cost effectiveness of the precursors leads to a quite convenient expected cost for the storage material, absolutely similar to commercially available accumulation systems.〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Mostafa Abuseada, Nesrin Ozalp〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel energy efficient variable aperture mechanism for a cavity-type solar receiver is presented. A 10 kW〈sub〉e〈/sub〉 solar simulator was used to experimentally test the receiver with and without the aperture mechanism and while the mechanism’s blades were uncooled and water-cooled. An in-house model of the system was developed by coupling a Monte Carlo ray tracing to a two-dimensional heat transfer analysis, which was then experimentally validated at three different solar simulator power levels, four different feedstock gas flow rates, and eight different aperture sizes. Using the validated model, it was determined that approximately 60% of the receiver’s input power is lost through radiation, which was mitigated by optimizing the receiver’s fixed aperture size. It was observed that the receiver’s temperature non-uniformity decreases as the aperture size reduces and its temperatures peak at a certain optimum aperture size, which decreases as the input power level increases. As for the aperture mechanism, water-cooling the aperture mechanism had no apparent impact on the receiver’s temperature distribution. Furthermore, the aperture mechanism did not demonstrate the same desirable behaviors as varying the receiver’s fixed aperture size, such as obtaining peak temperatures at certain smaller sizes. Nevertheless, the aperture mechanism was shown to be a very promising technique to regulate a solar receiver’s temperature and compensate for intermittent solar irradiance since the results showed that the aperture mechanism can regulate the average temperature within the range of 475–800 °C and while capturing and recovering 54% of any surplus power it intercepts.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Ruchi Aggarwal, Deepika Saini, Buta Singh, Jaidev Kaushik, Anjali Kumari Garg, Sumit Kumar Sonkar〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A simple and sustainable approach is described for the synthesis of photoactive carbon dots (CD) as an efficient photo-catalytic material. The photoactive-CD has been fabricated by simply charring the peels of Bitter Apple (BA). It is somewhat similar to the biochar synthesis. The photoactivity of BA peel derived photoactive-CD was tested under the illumination of sunlight for photodegradation of a pollutant organic dye, crystal violet (CV). A possible mechanism has been proposed for photodegradation of dye based on the trap experiment, where electron and holes were majorly responsible. BA peel derived photoactive-CD showed remarkable results concerning the photodegradation of CV (20 ppm in ~ 90 min) under sunlight illumination as compared to the dark conditions.〈/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-S0038092X2030013X-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Khawar Saeed Khan, Waseem Amjad, Anjum Munir, Oliver Hensel〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The improper post milking handling and storage results in a complete wastage due to the microorganisms and bacterial multiplication present in raw milk. The torque load minimalizing in the chilling unit using a solar photovoltaic (PV) is indeed a challenging task for the smooth functioning of the milk chilling system especially for the conventional (reciprocating) type of compressors. The variable refrigerant flow (VRF) technology not only solves the toque load problem but also reduces the size of peak power requirement of PV array. The present study enables the design of an improved solar chilling system consists of a chilling tank (200 L capacity) coupled with one tonne of refrigeration unit powered by PV panels (2 kWp) and employing VRF technology to make system more energy efficient by reducing the torque load. Experiments were conducted using different batch sizes (50, 100, 150 and 200 L) to decrease the raw milk temperature from 30 °C to 4 °C. During optimization phase the comparative power required to run various types of compressors (reciprocating, rotary with capacitor and rotary with VRF) were found to be 1.8 kW, 1.2 kW and 0.8 kW, respectively whereas the torque loads were noted to be 3.3 kW, 1.6 kW and zero kW for respective compressor type. The experimental and modeled predicted power consumption and chilling time under different batch sizes revealed excellent correlation coefficient (R〈sup〉2〈/sup〉 = 0.99, P 〈 0.0001). Around one tonne of refrigeration unit is sufficient to chill 200 L of milk up to 4 °C within less than two hours.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Sadjad Tajdaran, Christopher Kendrick, Edward Hopkins, Fabrizio Bonatesta〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Transpired Solar Collectors (TSCs) are simple low maintenance air heating systems which have been widely used for agricultural and industrial applications. In spite of their potential, these systems have not been yet widely employed in residential buildings as they are unable to generate high grade heat for moderate and low ventilation demands. Hence there is an opportunity for optimisation studies in order to enhance the thermal performance of these systems.〈/p〉 〈p〉Optimisation and parametric studies can be costly and time consuming if carried out by physical experiments. CFD models however offer a more flexible and less expensive tool to carry out such studies. This research has aimed to optimise the geometry of the solar absorber plate using a validated CFD model which accounts for a wide range of the key factors affecting TSC performance.〈/p〉 〈p〉A 2nd order polynomial predictive model was developed based on the CFD results with Root Mean Squared Error (RMSE) of 3.8%. The predictive model was used to identify an optimal geometry which delivers a Heat Exchange Effectiveness (HEE) of 0.739. The optimised geometry demonstrated 43% increase in HEE whilst using 28% less material compared to the baseline geometry under the same operating conditions. This geometry can be integrated with other performance enhancement techniques to further improve the thermal performance of TSCs.〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Enqian Dai, Teng Jia, Yanjun Dai〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This research involves a GAX-based ammonia-water absorption heat pump, which utilizes solar energy and natural gas as heat source. The experiments of parabolic tough collector and GAX absorption heat pump were carried out separately. GAX absorption heat pump is operated when the ambient temperature is 4.31–11.07 °C, COP approaches 1.44–1.66. Thermal efficiency of the PTC varies from 0.50 to 0.60. A mathematical model of the coupled solar absorption heat pump is built. The effect of each heat exchanger size on the GAX cycle performance is investigated, results show that the heat exchanger size of solution cooled absorber has the greatest impact on the cycle. Both Solar driven mode and Solar-NG driven mode were studied. Solar driven mode is strict with solar energy, if the direct normal irradiance is below 560 W/m〈sup〉2〈/sup〉 the system cannot work. Solar-NG driven mode could work under any solar radiation condition. In this mode, generation temperature could be controlled by changing the flow rate of natural gas. The optimal generation temperature is found to be around 180 °C when T〈sub〉amb〈/sub〉 = 7 °C, DNI = 800 W/m〈sup〉2〈/sup〉, T〈sub〉wout〈/sub〉 = 45 °C. Besides, system analysis reveals that the heat pump could perform competitive in low ambient temperature if the solar radiation is abundant, which makes Lhasa a perfect site for the system. Economic analysis in Lhasa show that the addition of solar collector could reduce the operating cost by more than 25%.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Ibrahim Olanrewaju Alade, Mohd Amiruddin Abd Rahman, Zulkifly Abbas, Yazid Yaakob, Tawfik A. Saleh〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper presents the modelling of the specific heat capacity (SHC) of CuO/water nanofluids using a support vector regression (SVR) and artificial neural network models (ANN). The models presented were developed from the experimental data of SCH of CuO nanoparticles, the volume fractions of CuO nanoparticles and fluid temperature. The volume fraction of CuO nanoparticles considered ranges from 0.4 to 2% while the temperature range includes 293–338 K. The results obtained revealed that the SVR model exhibits slightly higher accuracy compared to the ANN model. However, both the SVR and ANN models clearly demonstrate better prediction performance for the SHC of CuO/water nanofluids compared to the existing theoretical models. The results obtained in this study proves that machine learning models provide a more accurate estimation of SHC of CuO/water nanofluids and they are recommended for heat transfer calculations due to their superior accuracy.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Erdem Elibol〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Quantum Dot Sensitized Solar Cells (QDSSC) is one of the most focused energy sources among the 3rd generation energy sources with the theoretically promised energy conversion efficiency. Even though the experimental studies have been far from the maximum efficiency that should be obtained theoretically, efficiency continues to increase rapidly with new application and treatment methods. One of the problems to be solved in QDSSC technology is the selection of the counter electrode (CE) and electrolyte that is compatible with the synthesized QD, and the studies on this subject are limited compared to other studies. In this study, CdSeTe QDSSCs were designed in combination with 3 different CE (Au, Pt, Cu〈sub〉2〈/sub〉S) and 2 different electrolytes (triiodide, polysulfide) and the effects of CEs on QDSSC performance were compared. As a result of the study, it was determined that the use of Cu〈sub〉2〈/sub〉S CE/polysulfide electrolyte in the design of CdSeTe QDSSS increased PCE up to 1.408%. The highest filling factor (FF) and highest V〈sub〉oc〈/sub〉 values ​​were obtained by Pt CE/triiodide electrolyte in these studies and these values ​​were 60.664% and 0.730 V, respectively.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Gaëlle Faure, Mathieu Vallée, Cédric Paulus, Tuan Quoc Tran〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉All technical processes are subject to dysfunctions during their lifespan, and large solar thermal systems (LSTS) are no exception to this rule. The development of robust fault detection and diagnosis (FDD) methods is therefore a key issue. This paper reports on a review of faults types that can affect LSTS as well as the current approaches to detect and diagnose them. After a brief description of the system, a literature review of its dysfunctions is presented and the results of a study to complete and organize the inventory of these faults are described. The critical faults are defined. The state of the art of the research concerning FDD methods for LSTS is then detailed and demonstrates that this topic is of current interest. Finally, the performance of current algorithms is evaluated by two different ways: first along a list of desirable characteristics of a FDD method for LSTS, second along the ability of each method to detect the critical faults. This evaluation shows that there is room for some improvements in detecting and diagnosing faults for LSTS and these avenues are discussed.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Michael Alva, Alex Vlachokostas, Nicholas Madamopoulos〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Two significant design strategies for mitigating building energy consumption are daylight redirection and solar energy harvesting. Effective daylighting implementation enhances the amount of useful natural light within a space and offsets the need for electric lighting. Solar energy harvesting systems can mitigate energy costs from mechanical systems by managing incoming thermal loads or capturing solar energy that can be used to supplement thermal systems in the building. While there are many available façade-based technologies that can perform daylighting or solar thermal energy harvesting, there remains a limitation in available systems that can perform both of them simultaneously. This paper, describes the design and experimental demonstration of a Liquid Filled Prismatic Louver (LFPL) system, which combines both energy-saving strategies. The LFPL system was installed in a south-facing room in New York City and evaluated for indoor daylight penetration and potential for thermal energy harvesting. Daylight redirection is achieved through the prismatic louver geometry and proper orientation, whereas thermal energy harvesting is achieved through IR absorption from the liquid (e.g., water) within the prisms. Daylighting performance was evaluated by illuminance measurements at key locations within the space, whereas thermal harvesting performance was evaluated through temperature measurements and thermal imaging analysis. We show that the LFPL system, with all prismatic elements oriented at the same angle, achieve a 2-fold and 8-fold enhancement in daylight redirection to the ceiling, for prism orientations of 10° and 20°, respectively. We also demonstrate the system’s capability to adjust to specific lighting needs, within the space, through the dynamic individual orientation of prismatic elements; thus, achieving a concentrated ceiling illuminance enhancement of ~100 times and ~200 times at 2.5 and 4.3 m away from the window sill, providing workplane illuminance enhancement of 6 and 2 times more than in the case of the control room with regular windows. Furthermore, we show a reduction of potential heating loads at locations close to the window from the combination of infrared absorption in the water volume and the redirection of the incoming solar radiation, leading to a reduction of the workplane temperature by an average of 7–10 °C.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Hande Özge Güler, Adnan Sözen, Azim Doğuş Tuncer, Faraz Afshari, Ataollah Khanlari, Ceylin Şirin, Afsin Gungor〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In the present work, double-pass indirect solar dryer (DPISD) and double-pass indirect solar dryer with mesh absorber modification (DPISDMA) have been designed, analyzed, manufactured and tested. The main aim of this study is improving the thermal efficiency of double-pass solar air collector by integrating iron meshes. Pepino fruit (〈em〉Solanum muricatum L〈/em〉.) samples in two thicknesses have been used in the experimental study. Also, CFD analysis of both solar air collectors and drying chamber and quality metrics such as phenolic, total flavonoid contents and antioxidant activity have been conducted. Numerical simulation and experimental results showed that using mesh modification has positive influence on the performance of the collector. The highest value of the average efficiency of the dryer was obtained in DPISDMA for the thin sample thickness as 23.08%. According to quality analyses, the experiments which done in DPISDMA gave the best results with highest values of TPC, TFC and antioxidant activity values (p 〈 0.05). Drying data of the pepino fruit for different experiments were modelled according to 8 different most used mathematical models. Accordingly, the best fitted kinetics model was determined as Logarithmic model for all experiments which gave the most accurate statistical values.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Anil Kumar, Mamta Sharma, Pankaj Thakur, Vijay Kumar Thakur, Sameer S. Rahatekar, Rajesh Kumar〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Exergy analysis is very helpful for reducing irreversibility and rising the efficiency of solar collectors. The major objective of the present study is to organize a review on exergy analysis of different parabolic solar collectors. The effects of various flows and geometrical parameters of parabolic thermal collectors on the exergy efficiency were presented and discussed. In addition, comparative study was carried out to select the best solar thermal system for maximum exergy efficiency with minimal thermal losses. This study indicated that the hybrid nanofluids enhanced the exergy efficiency significantly as compared to without hybrid nanofluids. Passive techniques comprising twisted tape inserts, fins and insertion of swirl devices in the stream for changing the stream patterns causes to interrupt the thermal boundary layer and accordingly high exergy efficiency. This review would also throw light on the scope for further research and recommendation for improvement in the existing solar thermal collectors. Finally, this work will be beneficial for the scholars working on exergy analyses of solar parabolic collectors.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Hikmat S. Hilal, Ahed Zyoud, Mohammad H.S. Hilal, Heba Bsharat, Heba Nassar, Ali Cheknane〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Photovoltaics (PVs) show high conversion efficiency in renewable energy. However, PV systems demand advanced preparations and relatively large amounts of staring materials. Photoelectrochemical (PEC) systems, with monolithic semiconductor (SC) electrode/Redox couple interface, emerged, but still demand special preparation conditions and relatively large amounts of starting materials. Polycrystalline film electrodes, are studied as replacement for monolithic SC electrodes, both theoretically and experimentally. Examples are dye-sensitized solar cells (DSSCs) and metal chalcogenides. With narrow-to-medium band gaps, metal chalcogenides are suitable for the abundant visible solar light. However, polycrystalline film electrodes suffer major shortcomings. Pristine films show low conversion efficiency. Being polycrystalline, they have low carrier mobility. They are also unstable to photo-corrosion, due to charge build-up in the space charge layer (SCL). Enhancement of polycrystalline film electrode PEC performance and stability was reported using different methods. Among those, 〈em〉charge transfer catalysis at the film electrode surface〈/em〉, is focused here. The modification involves attaching electroactive species to the electrode surface. Ability of electroactive species to behave as charge transfer catalysts at the solid/liquid interface is discussed. By such behavior, the catalysts speed up charge transfer and consequently increase photocurrent. Moreover, charge build-up in the SCL is prevented by quick charge transfer, which protects the electrode surface from photo-corrosion. Ability of charged electroactive species to shift flat band edge position, with its consequences, is also described. Recommended features of an effective catalyst species for PEC systems are described together with recommendations for more future research in the field.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Using a charged transfer catalyst in a PEC cell may lower flat band edge positions, enhance short circuit photocurrent density at electrode/Redox interface and prevent electrode photo-corrosion.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0038092X20300347-ga1.jpg" width="289" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Srinivasa Rao Pathipati, Muhammad Naeem Shah, Xiaofang Pan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The addition of a tiny amount of fluorescent organic material N, N′-di (naphtha-1-yl)-N, N′-diphenyl-benzidine (NPB) into polymeric hole transport layer (HTL) is shown to yield a significant enhancement in down-conversion of ultraviolet (UV) light into visible light. As a result, NPB incorporated HTL based devices exhibit enhancement in power conversion efficiency (PCE) of 18.2% compared to 15.1% for pristine devices. This work demonstrated that fluorescent down-conversion of UV light based on doped HTLs is a novel and effective approach for enhanced performance of perovskite solar cells (PSCs). In addition, the incorporated fluorescent material NPB provides a favorable energetic alignment at the interface for low voltage loss. These results are further supported by time-resolved photoluminescence (TRPL) measurements that are performed on perovskite layers deposited on top of NPB doped Poly (triaryl amine) (PTAA), which shows an improvement in lifetime of the charge carriers with increasing concentration of NPB. An increase in the lifetime of the charge carriers is observed on the perovskite layer that is deposited on top of 2.5 wt% NPB doped PTAA layer. The lifetime enhancement is due to additional charge carriers that are generated from the conversion of high energy photons to low energy photons. These additional charge carriers that are generated in HTL occupy the charge transport states after filling the trap states in the perovskite layer and hence the lifetime of the charge carriers increases. The TRPL lifetime decreases with further increase in the NPB concentration more than 2.5 wt% due to efficient charge carrier extraction.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Jian Yao, Hui Xu, Yanjun Dai, Mingjun Huang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉PV/T (photovoltaic/thermal) technology is a combination of PV module (photovoltaic utilization) and collector (photothermal utilization), which can improve the comprehensive utilization efficiency of solar energy and has a broad application prospect. In this paper, PV/T module is coupled with heat pump evaporator to form a direct-expansion solar PV/T heat pump which is suitable for heat application in high latitude area. To achieve stable residential heating, a solar PV/T heat pump system coupled with build-in PCM (phase change material) heat storage is therefore proposed and simulated. Meanwhile, the mathematical model of solar PV/T heat pump coupled with build-in PCM heat storage system is established and verified. The simulation results show that the temperature of underfloor heating which using build-in PCM heat storage can reach 22–31 °C after 39 h when the circulating water is 40 °C. Moreover, the heating COP (Coefficient of Performance) increases with the increase of solar radiation, ambient temperature and area of PV/T collector, and decrease of wind speed, respectively. A 20 m〈sup〉2〈/sup〉 PV/T panel module can output 21.4% of the electricity to power grid when the solar radiation intensity is 600 W/m〈sup〉2〈/sup〉 and meet the heat demand of a 100 m〈sup〉2〈/sup〉 room while maintain the operation of the system. Meanwhile, the heating COP can reach 5.79 which is 70% higher than the conventional air conditioning system and the electrical, thermal, overall efficiencies are 17.77%, 55.76% and 75.49%, respectively.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: February 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 197〈/p〉 〈p〉Author(s): Pramod Mishra, Kelli Stockmal, Giuseppe Ardito, Mingjiang Tao, Steven Van Dessel, Sergio Granados-Focil〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Many phase change materials (PCMs) experience a change in transparency when undergoing a phase transition. These thermo-optically responsive materials can be used to generate passive temperature control systems for building enclosures. The integration of optical and thermal switches into smart temperature-controlling elements requires rationally designed PCMs featuring tunable optical and thermal properties. Two polymers, poly (Octadecyl methacrylate) (PSMA) and poly(2-(2-(octadecyloxy) ethoxy) ethyl methacrylate) (PE2SMA) were synthesized and evaluated for their potential use in passive thermal energy storage systems. UV–Visible Spectroscopy, Near Infra-Red Spectroscopy, and Differential Scanning Calorimetry were used to evaluate the effect that changes in the polymer chemical structure had on the optical and thermal properties of the resulting materials. Insertion of a 6-atom flexible spacer (diethylene glycol) between the pendant crystalline motif and the polymer backbone of PSMA resulted in increases of latent heat storage capacity from 62 J/g to 94 J/g and thermal conductivity from 0.218 W/mK to 0.318 W/mK. Notably, insertion of a flexible spacer also resulted in a melting transition temperature increase from 37.7 °C for PSMA to 48 °C for PE2SMA. The visible transmittance of the polymers increased from 0% to 90% upon transition from crystalline to amorphous state. This study presents a synthetic strategy to control thermal and optical properties of polymeric PCMs materials. The material properties and structure-property relationships derived from this study will enable the refinement of the models used to predict the performance of passive temperature-regulating systems. More accurate models will guide the development of the thermo-responsive polymeric materials required for better perfoming temperature-regulating building enclosures.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 199〈/p〉 〈p〉Author(s): Ali M. Humada, Salih Y. Darweesh, Khalid G. Mohammed, Mohammed Kamil, Samen F. Mohammed, Naseer K. Kasim, Tahseen Ahmad Tahseen, Omar I. Awad, Saad Mekhilef〈/p〉

Beschreibung: 〈p〉Publication date: 15 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 199〈/p〉 〈p〉Author(s): Changwei Cai, Xu Ouyang, Lan Zhou, Guojin Liu, Yan Wang, Guocheng Zhu, Juming Yao, Jiri Militky, Mohanapriya Venkataraman, Guoqing Zhang〈/p〉

Beschreibung: 〈p〉Publication date: 15 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 199〈/p〉 〈p〉Author(s): Oussama Touaba, Mohamed Salah Ait Cheikh, Mohamed El-Amine Slimani, Ahmed Bouraiou, Abderrezzaq Ziane, Ammar Necaibia, Arezki Harmim〈/p〉

Beschreibung: 〈p〉Publication date: 15 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 199〈/p〉 〈p〉Author(s): Boon-Han Lim, Chern-Sing Lim, Hu Li, Xing-Lan Hu, Kok-Keong Chong, Jin-Long Zong, Ke Kang, Woei-Chong Tan〈/p〉

Beschreibung: 〈p〉Publication date: 15 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 199〈/p〉 〈p〉Author(s): N. Martínez, A. Rico, C.J. Múnez, C. Prieto, P. Poza〈/p〉

Beschreibung: 〈p〉Publication date: 15 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 199〈/p〉 〈p〉Author(s): Zisheng Lu〈/p〉

Beschreibung: 〈p〉Publication date: 15 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 199〈/p〉 〈p〉Author(s): Zhengqi Liu, Haozong Zhong, Houjiao Zhang, Zhenping Huang, Guiqiang Liu, Xiaoshan Liu, Guolan Fu, Chaojun Tang〈/p〉

Beschreibung: 〈p〉Publication date: 15 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 199〈/p〉 〈p〉Author(s): Qiangqiang Xiao, Jiahao Cao, Yixue Zhang, Li Li, Tao Xu, Wenhui Yuan〈/p〉

Beschreibung: 〈p〉Publication date: 15 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 199〈/p〉 〈p〉Author(s): Hatem Hasan Ismaeel, Recep Yumrutaş〈/p〉

Beschreibung: 〈p〉Publication date: 15 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 199〈/p〉 〈p〉Author(s): María Privado, Pilar de la Cruz, Guarav Gupta, Rahul Singhal, Ganesh D. Sharma, Fernando Langa〈/p〉

Beschreibung: 〈p〉Publication date: 15 March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Solar Energy, Volume 199〈/p〉 〈p〉Author(s): Mahfoudh Raïssi, Yann Pellegrin, François-Xavier Lefevre, Mohammed Boujtita, Didier Rousseau, Thomas Berthelot, Fabrice Odobel〈/p〉