Journal of Renewable Energy最新文献

{"title":"Maximization of Site-Specific Solar Photovoltaic Energy Generation through Tilt Angle and Sun-Hours Optimization","authors":"Macben Makenzi, J. Muguthu, E. Murimi","doi":"10.1155/2020/8893891","DOIUrl":"https://doi.org/10.1155/2020/8893891","url":null,"abstract":"Many photovoltaic solar projects do not achieve optimum energy and power outputs due to poor technical sizing and system design approaches. Concerns on low-conversion rates, high intermittencies, and high-capital costs still haunt PV projects. The establishment of design methodologies that would result in increased outputs from solar arrays is crucial in addressing the aforementioned issues. The tilt angles of installed PV modules are critical factors that influence the power output of solar modules. Several resources are available that provide generic linear fits and estimation of tilt angles for various global regions. However, very few are capable of determining precise, location-specific tilt angles that would allow for optimal power output and energy generation. This paper presents a methodology developed to establish the optimum tilt angles for solar panels installed at specific locations, thus ensuring maximum energy generation. The modeling is based on the maximization of the solar irradiation incident on the surface of a PV panel by considering multiple site-specific variables. Different sets of transcendent equations have been derived which were used to calculate optimum tilt angles and the subsequent energy generation from specific configurations of photovoltaic arrays. The resulting algorithms were used to determine optimum tilt angles and energy generation for solar PV installations in Athi River, Kenya. Dynamic and static optimal tilt angles were compared with the region’s baseline industry practice of using a fixed tilt angle of 15◦. It was observed that the dynamic tilt angles improved the daily solar energy output by up to 6.15%, while the computed optimal static tilt angle provided a 2.87% output increment. This improvement presents a significant impact on the technical specification of the PV system with a consequent reduction in the investment and operational cost of such installations. It further demonstrated that the use of the optimum static tilt angle results in cost and space savings of up to 2.8% as compared to the standard industry practice. Additionally, 5.8% cost and space savings were attained by the utilization of dynamic tilt angles.","PeriodicalId":30460,"journal":{"name":"Journal of Renewable Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/8893891","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43365271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Meteorological Drivers of European Power System Stress","authors":"H. Bloomfield, C. C. Suitters, D. Drew","doi":"10.1155/2020/5481010","DOIUrl":"https://doi.org/10.1155/2020/5481010","url":null,"abstract":"A rapid decarbonisation of power systems is underway in order to limit greenhouse gas emissions and meet carbon-reduction targets. Renewable energy is a key ingredient to meet these targets; however, it is important that national power systems still maintain energy security with increasing levels of renewable penetration. The operating potential of renewable generation at times of peak demand (a critical time for power system stress) is not well understood. This study therefore uses a multidecadal dataset of national demand, wind power, and solar power generation to identify the meteorological conditions when peak demand occurs and the contribution of renewables during these events. Wintertime European peak power demand events are associated with high atmospheric pressure over Russia and Scandinavia and are accompanied by lower than average air temperatures and average wind speeds across Europe. When considering power demand extremes net of renewable power production, the associated meteorological conditions are shown to change. There is considerable spatial variability in the dates of national peak demand events and the amount of renewable generation present. Growth in renewable generation has the potential to reduce peak demands. However, these impacts are also not uniform with much larger reductions in peak demand seen in Spain than in central Europe. The reanalysis-derived energy models have allowed recent peak demand events to be put into a long-term context.","PeriodicalId":30460,"journal":{"name":"Journal of Renewable Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/5481010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45612035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Global Value Chain Embedding on Total-Factor Energy Productivity of Chinese Industrial Sectors","authors":"Xiwen Feng, Mingshang Xin, Xinghua Cui","doi":"10.1155/2020/6239640","DOIUrl":"https://doi.org/10.1155/2020/6239640","url":null,"abstract":"In the four decades since China’s reform and opening up, China has been playing an active role in global value chain (GVC) due to its abundant resources. China has gained enormous benefits from opening up, but has also suffered huge energy costs in the process. In this study, we incorporated global value chains and energy consumption into a unified analysis framework and calculated the energy total-factor productivity (ETFP) of China’s industry and the degree of participation in GVC. In addition, in order to discover the contradictions and problems between China's participation in global value chains and the improvement of total energy factor productivity, the panel smooth transformation model (PSTR) was used to empirically test the nonlinear relationship between the ETFP and the degree of participation in GVC in China. From the analysis results, GVC participation, as well as the subdivided shallow GVC participation and deep GVC participation, first promoted the effect on ETFP and then suppressed it, showing an inverted U-shaped single threshold characteristic. The results indicated that in the progress of starting to participate in the GVC, the effect of technological progress of the GVC overweighed the scale effect of energy consumption, resulting in the growth of ETFP. However, due to the gradual reduction of technology dividends and the “low-end lock-in” situation, China was placed in the value chain by the developed countries, and the technological effect was gradually smaller than the scale effect of energy consumption. As a result, the increase in the total-factor productivity of energy was inhibited. At the same time, in the further examination of industry heterogeneity, the inverted U-shaped influence trend was more significant in high energy-consuming industries. The conclusions of this study can provide a new perspective and policy focus for China's participation in GVC to achieve the goal of increasing ETFP.","PeriodicalId":30460,"journal":{"name":"Journal of Renewable Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/6239640","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46330204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Rooftop Photovoltaics on the Distribution System","authors":"Kamel Alboaouh, S. Mohagheghi","doi":"10.1155/2020/4831434","DOIUrl":"https://doi.org/10.1155/2020/4831434","url":null,"abstract":"This paper presents a review of the impact of rooftop photovoltaic (PV) panels on the distribution grid. This includes how rooftop PVs affect voltage quality, power losses, and the operation of other voltage-regulating devices in the system. A historical background and a classification of the most relevant publications are presented along with the review of the important lessons learned. It has been widely believed that high penetration levels of PVs in the distribution grid can potentially cause problems for node voltages or overhead line flows. However, it is shown in the literature that proper control of the PV resource using smart inverters can alleviate many of those issues, hence paving the way for higher PV penetration levels in the grid.","PeriodicalId":30460,"journal":{"name":"Journal of Renewable Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/4831434","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48691429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling and Analysis of Photo-Voltaic Solar Panel under Constant Electric Load","authors":"Elias M. Salilih, Y. T. Birhane","doi":"10.1155/2019/9639480","DOIUrl":"https://doi.org/10.1155/2019/9639480","url":null,"abstract":"This paper presents modelling electrical performance of a typical PV panel/module (which is Kyocera 200GT) for constant electric loads (which are 2Ω, 4Ω, 6Ω, and 8Ω) under weather condition of a tropical region. The specific case of the city Jigjiga (9.35°N,42.8°E), located in the Eastern region of Ethiopia is considered. Electrical characteristics of the PV module are determined on the basis of detailed numerical algorithm, which was designed based on tested numerical technique from reviewed articles. The overall evaluation of the hourly variation in the electrical performance of the PV module is done by means of graphical technique, which determines the operating point of the PV module on voltage vs. current plane for each load, and the performance of the PV panel is compared for each load. The 4Ω electric load resulted in highest daily energy output of the PV panel on a daily basis for 11 days of the month of January (out of 12 considered days), but in the last day it resulted in a poorer performance with respect to the other two electrical loads (i.e., 6Ω and 8Ω electric loads).","PeriodicalId":30460,"journal":{"name":"Journal of Renewable Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/9639480","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42070851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Comprehensive Study on the Physicochemical Characteristics of Faecal Sludge in Greater Accra Region and Analysis of Its Potential Use as Feedstock for Green Energy","authors":"Issahaku Ahmed, Dennis Ofori-Amanfo, E. Awuah, Florence Cobbold","doi":"10.1155/2019/8696058","DOIUrl":"https://doi.org/10.1155/2019/8696058","url":null,"abstract":"Design of treatment plants for faecal sludge management systems relies on a comprehensive accurate knowledge of FS (faecal sludge) characteristics, but this information is lacking. Developing countries like Ghana, where large proportion of the urban population (Accra) rely on onsite sanitation systems, face a lot of FSM (faecal sludge management) design challenges as a result of lack of a comprehensive study data on physicochemical characteristics of raw faecal sludge after primary dewatering. Achieving a fully operational FSM chain would imply a well understanding of the characteristics of the FS and its dynamics after primary dewatering. A study was carried out to determine the characteristics of faecal sludge brought to the Lavender Hill treatment plant, Accra Metropolis, and environs to ensure the treatability and uses of the products after treatment. The treatment plant receives an average of 150 trucks (1350m3) a day with 58% coming from private homes and 42% from public toilets. Composite samples were made from both public and private toilets facilities. Samples were taken from a reservoir holding faecal sludge from both public and private facilities, examined on daily basis and characterized. The values obtained showed high concentrations of BOD and COD values. The COD: BOD ratios showed that the faecal sludge is not stabilized yet and can be further degraded. The calorific value for the dry sludge was found to be 15.16-15.82 MJ/kg and 16.39–18.31 MJ/kg for the wet sludge. The calorific value of the sludge is adequate enough to be used as potential feedstock for green energy generation. The high concentrations of COD and organic matter of the faecal sludge make it suitable enough for biogas generation. A good correlation (r=0.909,R2=82.6%) between the calorific value and the TVS was found to be CV=0.122TVS+7.44. Heavy metal concentrations were low and satisfied the EPA Ghana guidelines for sludge. Thus products from the treatment can be used for agricultural purposes.","PeriodicalId":30460,"journal":{"name":"Journal of Renewable Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/8696058","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47114943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Functional Metagenomics Characterization of an Anaerobic Saltwater Bioreactor","authors":"D. Derilus, A. Forestil, J. Fortune, O. Polyanska, C. Louime, G. Gervais, S. Massey","doi":"10.1155/2019/4527628","DOIUrl":"https://doi.org/10.1155/2019/4527628","url":null,"abstract":"Methanogens are restricted to a few genera of Archaea, however they have great importance in the carbon cycle, impacting climactic considerations, and also find a role in renewable energy in the form of biogas. Here, we examine the microbial contribution to the production of methane in a sargassum fed anaerobic saltwater bioreactor, which are poorly characterized compared to fresh water bioreactors, using a comprehensive functional metagenomics approach. Despite abundant production of methane, we detected a low proportion of Archaea in the system using 16S rRNA community profile analyses. We address the low representation using an additional 16S rRNA analysis of shotgun data and a consideration of CO2:CH4production. Using a novel network alignment and tree building approach, we measured similarity between the meta-metabolic capabilities of different anaerobic microbial communities. The saltwater bioreactor samples clustered together, validating the approach and providing a method of determining meta-metabolic similarity between microbial communities, with a range of potential applications. We also introduce a number of additional approaches for examining and interpreting meta-metabolic network topology. The low abundance of methanogens appears as a common property of such anaerobic systems and likely reflects the relatively poor energetics of methanogens, while examination of key enzymes confirms that hydrogen producing bacteria are the major fermentative guild. Our results indicate that the use of readily available seawater and marine macroalgae is a promising approach to the production of biogas as a source of renewable energy.","PeriodicalId":30460,"journal":{"name":"Journal of Renewable Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/4527628","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41771150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Characterisation of Photovoltaic Modules with Cells Connected in Different Configurations to Address Nonuniform Illumination Effect","authors":"Damasen Ikwaba Paul","doi":"10.1155/2019/5168259","DOIUrl":"https://doi.org/10.1155/2019/5168259","url":null,"abstract":"Most concentrating systems that are being used for photovoltaic (PV) applications do not illuminate the PV module uniformly which results in power output reduction. This study investigated the electrical performance of three PV modules with cells connected in different configurations to address nonuniform illumination effect. PV module 1 is the standard module consisting of 11 solar cells connected in series whereas PV module 2 is a proposed design with 11 cells in three groups and each group consists of different cells in series connections. PV module 3 is also a new design with 11 cells in two groups and each group consists of different cells connected in series. The new PV modules were designed in such a way that the effect of nonuniform illumination should affect a group of cells but not the entire PV module, leading to high power output. The PV modules were tested under three different intensities: uniform, low nonuniform, and high nonuniform illumination. When the PV modules were tested at uniform illumination, the total maximum power output of PV module 1 was higher than that of PV module 2 and PV module 3 by about 7%. However, when the PV modules were tested at low nonuniform illumination, the total maximum power output of PV module 2 was higher than that of PV module 1 and PV module 3 by about 4% and 7%, respectively. This difference increased to about 12% for PV module 3 and 17% for PV module 1 when the modules were tested at high nonuniform illumination. Therefore, the best PV module design in addressing nonuniform illumination effect in solar collectors is PV module 2. In practical situation this implies that manufacturers of PV modules should consider designing modules with groups of cells in series connection instead of all cells being connected in series.","PeriodicalId":30460,"journal":{"name":"Journal of Renewable Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/5168259","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46200637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Comparison Analysis of the Experimental and Theoretical Power Output of a Hybrid Photovoltaic Cell","authors":"Damasen Ikwaba Paul","doi":"10.1155/2019/3684284","DOIUrl":"https://doi.org/10.1155/2019/3684284","url":null,"abstract":"In this paper, experimental and theoretical power output of a hybrid photovoltaic cell were analysed and compared for three different weather conditions (clear sky, partial cloudy, and overcast days). The hybrid photovoltaic cell consisted of low efficiency cell (mono-crystalline) and strips of Bosch M 2BB mono-crystalline cell as high efficiency cell. The current and voltage for the experimental results were measured by using optimal resistive load method. Theoretical daily power output of the hybrid PV cell was calculated based on the hourly incident energy on each section, the size of the section, and the electrical conversion efficiency of each section. The hybrid cell was evaluated within a low-concentrating symmetric compound parabolic concentrator suitable for building integration and was tilted at 54°. It was found that the theoretical daily power output on a clear sky, partial cloudy, and overcast days was higher than the experimental results by 136%, 109%, and 121%, respectively. The discrepancy was due to losses as the result of connecting wires series resistance effect, operating temperature effect, and the consequence of the fixed resistive load. However, it was the value of the optimal resistive load that had much impact on the experimental power output. To eliminate the restriction of the optimal resistive load on the experimental results, it is recommended to use data acquisition systems such as photovoltaic peak power measuring device 6020C 6020C or Keithley 2651A source-meter.","PeriodicalId":30460,"journal":{"name":"Journal of Renewable Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/3684284","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41776742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fault Ride-Through Capability Enhancement for Microinverter Applications","authors":"Sajad A. Ansari, Amirreza Mizani, S. Ashouri, J. Moghani","doi":"10.1155/2019/1036156","DOIUrl":"https://doi.org/10.1155/2019/1036156","url":null,"abstract":"Due to the fast growth of single-phase grid-connected photovoltaic (PV) systems, the existing grid codes are expected to be modified to guarantee the availability, quality, and reliability of the electrical system. Therefore, the future single-phase PV systems should become smarter and support low voltage ride-through (LVRT) capability, which are required for three-phase wind power systems. In this paper, the operation principle of a flyback inverter in a low-voltage ride-through operation is demonstrated in order to map future challenges. The steady state performance of the flyback inverter under voltage rise and drop conditions at boundary conduction mode (BCM) and discontinues conduction mode (DCM) is studied theoretically. The simulation results of the flyback inverter for various grid faults are presented to verify the theoretical analyses. The results indicate the fact that the flyback inverter at BCM condition can provide LVRT capability for photovoltaic microinverter applications in distributed generation (DG) systems, even though it does not need any auxiliary control branches and any limitations in components design.","PeriodicalId":30460,"journal":{"name":"Journal of Renewable Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/1036156","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48264450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}