scholarly journals Tailored Algorithms for Anomaly Detection in Photovoltaic Systems

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 225 ◽  
Author(s):  
Pedro Branco ◽  
Francisco Gonçalves ◽  
Ana Cristina Costa
Keyword(s):  
Time Series ◽  
Alternative Energy ◽  
Weather Conditions ◽  
Electricity Production ◽  
Pv System ◽  
Detection Algorithms ◽  
Pv Systems ◽  
Adverse Weather ◽  
Full Capacity ◽  
And Performance

The fastest-growing renewable source of energy is solar photovoltaic (PV) energy, which is likely to become the largest electricity source in the world by 2050. In order to be a viable alternative energy source, PV systems should maximise their efficiency and operate flawlessly. However, in practice, many PV systems do not operate at their full capacity due to several types of anomalies. We propose tailored algorithms for the detection of different PV system anomalies, including suboptimal orientation, daytime and sunrise/sunset shading, brief and sustained daytime zero-production, and low maximum production. Furthermore, we establish simple metrics to assess the severity of suboptimal orientation and daytime shading. The proposed detection algorithms were applied to a set of time-series of electricity production in Portugal, which are based on two periods with distinct weather conditions. Under favourable weather conditions, the algorithms successfully detected most of the time-series labelled with either daytime or sunrise/sunset shading, and with either sustained or brief daytime zero-production. There was a relatively low percentage of false positives, such that most of the anomaly detections were correct. As expected, the algorithms tend to be more robust under favourable rather than under adverse weather conditions. The proposed algorithms may prove to be useful not only to research specialists, but also to energy utilities and owners of small- and medium-sized PV systems, who may thereby effortlessly monitor their operation and performance.

scholarly journals Ship Handling in Unprotected Waters: A Review of New Technologies in Escort Tugs to Improve Safety

2021 ◽  
Vol 2 (1) ◽  
pp. 46-62
Author(s):  
Santiago Iglesias-Baniela ◽  
Juan Vinagre-Ríos ◽  
José M. Pérez-Canosa
Keyword(s):  
High Performance ◽  
New Technologies ◽  
Weather Conditions ◽  
Hull Form ◽  
Best Available Technologies ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
New Type ◽  
Technological Challenge ◽  
And Performance

It is a well-known fact that the 1989 Exxon Valdez disaster caused the escort towing of laden tankers in many coastal areas of the world to become compulsory. In order to implement a new type of escort towing, specially designed to be employed in very adverse weather conditions, considerable changes in the hull form of escort tugs had to be made to improve their stability and performance. Since traditional winch and ropes technologies were only effective in calm waters, tugs had to be fitted with new devices. These improvements allowed the remodeled tugs to counterbalance the strong forces generated by the maneuvers in open waters. The aim of this paper is to perform a comprehensive literature review of the new high-performance automatic dynamic winches. Furthermore, a thorough analysis of the best available technologies regarding towline, essential to properly exploit the new winches, will be carried out. Through this review, the way in which the escort towing industry has faced this technological challenge is shown.

scholarly journals Forecasting and Modelling of Solar Radiation for Photovoltaic (PV) Systems

2021 ◽  
Author(s):  
Ines Sansa ◽  
Najiba Mrabet Bellaaj
Keyword(s):  
Time Series ◽  
Solar Radiation ◽  
Cloud Cover ◽  
Moving Average ◽  
Arma Model ◽  
Weather Conditions ◽  
Pv Systems ◽  
Auto Regressive ◽  
Micro Grid ◽  
One Year

Solar radiation is characterized by its fluctuation because it depends to different factors such as the day hour, the speed wind, the cloud cover and some other weather conditions. Certainly, this fluctuation can affect the PV power production and then its integration on the electrical micro grid. An accurate forecasting of solar radiation is so important to avoid these problems. In this chapter, the solar radiation is treated as time series and it is predicted using the Auto Regressive and Moving Average (ARMA) model. Based on the solar radiation forecasting results, the photovoltaic (PV) power is then forecasted. The choice of ARMA model has been carried out in order to exploit its own strength. This model is characterized by its flexibility and its ability to extract the useful statistical properties, for time series predictions, it is among the most used models. In this work, ARMA model is used to forecast the solar radiation one year in advance considering the weekly radiation averages. Simulation results have proven the effectiveness of ARMA model to forecast the small solar radiation fluctuations.

scholarly journals Improved Synthesis of Global Irradiance with One-Minute Resolution for PV System Simulations

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Martin Hofmann ◽  
Stefan Riechelmann ◽  
Cristian Crisosto ◽  
Riyad Mubarak ◽  
Gunther Seckmeyer
Keyword(s):  
Time Series ◽  
High Resolution ◽  
Transition Probability ◽  
Weather Condition ◽  
Weather Conditions ◽  
Pv System ◽  
High Resolution Data ◽  
Frequency Distributions ◽  
Global Irradiance ◽  
Mean Square Errors

High resolution global irradiance time series are needed for accurate simulations of photovoltaic (PV) systems, since the typical volatile PV power output induced by fast irradiance changes cannot be simulated properly with commonly available hourly averages of global irradiance. We present a two-step algorithm that is capable of synthesizing one-minute global irradiance time series based on hourly averaged datasets. The algorithm is initialized by deriving characteristic transition probability matrices (TPM) for different weather conditions (cloudless, broken clouds and overcast) from a large number of high resolution measurements. Once initialized, the algorithm is location-independent and capable of synthesizing one-minute values based on hourly averaged global irradiance of any desired location. The one-minute time series are derived by discrete-time Markov chains based on a TPM that matches the weather condition of the input dataset. One-minute time series generated with the presented algorithm are compared with measured high resolution data and show a better agreement compared to two existing synthesizing algorithms in terms of temporal variability and characteristic frequency distributions of global irradiance and clearness index values. A comparison based on measurements performed in Lindenberg, Germany, and Carpentras, France, shows a reduction of the frequency distribution root mean square errors of more than 60% compared to the two existing synthesizing algorithms.

scholarly journals Cost-Benefit Analysis of Small-Scale Rooftop PV Systems: The Case of Dragotin, Croatia

2021 ◽  
Vol 11 (19) ◽  
pp. 9318
Author(s):  
Mladen Bošnjaković ◽  
Ante Čikić ◽  
Boris Zlatunić
Keyword(s):  
Renewable Energy Sources ◽  
Electricity Consumption ◽  
Electricity Production ◽  
Small Scale ◽  
Optimal Size ◽  
Pv System ◽  
Load Curve ◽  
Pv Systems ◽  
Hourly Data ◽  
Daily Load

A large drop in prices of photovoltaic (PV) equipment, an increase in electricity prices, and increasing environmental pressure to use renewable energy sources that pollute the environment significantly less than the use of fossil fuels have led to a large increase in installed roof PV capacity in many parts of the world. In this context, this paper aims to analyze the cost-effectiveness of installing PV systems in the rural continental part of Croatia on existing family houses. A typical example is a house in Dragotin, Croatia with an annual consumption of 4211.70 kWh of electricity on which PV panels are placed facing south under the optimal slope. The calculation of the optimal size of a PV power plant with a capacity of 3.6 kW, without battery energy storage, was performed by the Homer program. The daily load curve was obtained by measuring the electricity consumption at the facility every hour during a characteristic day in the month of June. As most of the activities are related to electricity consumption, repeating during most days of the year, and taking into account seasonal activities, daily load curves were made for a characteristic day in each month of the year. Taking into account the insolation for the specified location, using the Internet platform Solargis Prospect, hourly data on the electricity production of selected PV modules for a characteristic day in each month were obtained. Based on the previous data, the electricity injected into the grid and taken from the grid was calculated. Taking into account the current tariffs for the sale and purchase of electricity, investment prices, and maintenance of equipment, the analysis shows that such a PV system can pay off in 10.5 years without government incentives.

scholarly journals Mali

2019 ◽  
Vol 19 (289) ◽  
Author(s):  
Keyword(s):  
Low Income ◽  
Public Investment ◽  
Weather Conditions ◽  
Growth Potential ◽  
Peace Agreement ◽  
The North ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Interethnic Violence ◽  
And Performance

Mali is a low-income fragile country facing significant development challenges that have intensified due to insurgency, terrorism, and social tensions. Implementation of the 2015 peace agreement is challenging, and the authorities have limited control over the North and Center regions. Mali’s social development could be further undermined by the recent instability and interethnic violence that complicates the government’s ability to implement basic social and poverty-reducing programs. The economic outlook for Mali remains positive but subject to important downside risks. The potential real growth rate is estimated at about 5 percent per year and inflation is expected to continue to be contained by the CFAF’s peg to the euro. Downside risks relate to the possible further deterioration of the security situation, potential shocks to the terms of trade (the price of gold, cotton, and fuels), and adverse weather conditions. In addition, a continued shortfall in domestically-financed public investment, if revenue mobilization does not improve as expected, could adversely affect growth potential and performance.

scholarly journals A Novel Fault Classification Approach for Photovoltaic Systems

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 308 ◽  
Author(s):  
Varaha Satya Bharath Kurukuru ◽  
Frede Blaabjerg ◽  
Mohammed Ali Khan ◽  
Ahteshamul Haque
Keyword(s):  
Single Phase ◽  
Failure Detection ◽  
Fault Classification ◽  
Early Failure ◽  
Pv System ◽  
Electrical Systems ◽  
Pv Systems ◽  
And Performance ◽  
Training Efficiency ◽  
Better Than

Photovoltaic (PV) energy has become one of the main sources of renewable energy and is currently the fastest-growing energy technology. As PV energy continues to grow in importance, the investigation of the faults and degradation of PV systems is crucial for better stability and performance of electrical systems. In this work, a fault classification algorithm is proposed to achieve accurate and early failure detection in PV systems. The analysis is carried out considering the feature extraction capabilities of the wavelet transform and classification attributes of radial basis function networks (RBFNs). In order to improve the performance of the proposed classifier, the dynamic fusion of kernels is performed. The performance of the proposed technique is tested on a 1 kW single-phase stand-alone PV system, which depicted a 100% training efficiency under 13 s and 97% testing efficiency under 0.2 s, which is better than the techniques in the literature. The obtained results indicate that the developed method can effectively detect faults with low misclassification.

scholarly journals A Critical Appraisal of PV-Systems’ Performance

Buildings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 192
Author(s):  
Zainab Usman ◽  
Joseph Tah ◽  
Henry Abanda ◽  
Charles Nche
Keyword(s):  
Renewable Energy ◽  
Electric Energy ◽  
Geographical Location ◽  
Poor Performance ◽  
Performance Ratio ◽  
Energy Output ◽  
Pv System ◽  
Pv Systems ◽  
Energy Technologies ◽  
And Performance

Climate change and global warming have triggered a global increase in the use of renewable energy for various purposes. In recent years, the photovoltaic (PV)-system has become one of the most popular renewable energy technologies that captures solar energy for different applications. Despite its popularity, its adoption is still facing enormous challenges, especially in developing countries. Experience from research and practice has revealed that installed PV-systems significantly underperform. This has been one of the major barriers to PV-system adoption, yet it has received very little attention. The poor performance of installed PV-systems means they do not generate the required electric energy output they have been designed to produce. Performance assessment parameters such as performance yields and performance ratio (PR) help to provide mathematical accounts of the expected energy output of PV-systems. Many reasons have been advanced for the disparity in the performance of PV-systems. This study aims to analyze the factors that affect the performance of installed PV-systems, such as geographical location, solar irradiance, dust, and shading. Other factors such as multiplicity of PV-system components in the market and the complexity of the permutations of these components, their types, efficiencies, and their different performance indicators are poorly understood, thus making it difficult to optimize the efficiency of the system as a whole. Furthermore, mathematical computations are presented to prove that the different design methods often used for the design of PV-systems lead to results with significant differences due to different assumptions often made early on. The methods for the design of PV-systems are critically appraised. There is a paucity of literature about the different methods of designing PV-systems, their disparities, and the outcomes of each method. The rationale behind this review is to analyze the variations in designs and offer far-reaching recommendations for future studies so that researchers can come up with more standardized design approaches.

Analysis and Performance of a Two-Axis PV Tracker in Southern Spain

2011 ◽  
Vol 133 (1) ◽  
Author(s):  
G. Almonacid ◽  
E. Muñoz ◽  
F. Baena ◽  
P. Pérez-Higueras ◽  
J. Terrados ◽  
...  
Keyword(s):  
Southern Spain ◽  
Performance Ratio ◽  
System Behavior ◽  
Average Yield ◽  
Pv System ◽  
Yield Increase ◽  
Pv Systems ◽  
Productivity Data ◽  
And Performance ◽  
The University

El Girasol, a two-axis photovoltaic (PV) tracker system of 9.6 kWp connected to the grid at the Campus of the University of Jaén in Southern Spain, has reached an average yield of 2092 kWh/kWp·year. As far as it is known, it is one of the highest productivity data reported up to now in PV systems. This paper presents a description of the system and the working analysis during 2 years of operation. Related to the system behavior, the following performances are highlighted: global efficiency of 10.4%, performance ratio of 73.1%, a yield increase versus a fixed and ideally faced PV system of 45.8%, and high operation reliability with minimal maintenance needs.

scholarly journals Solar Photovoltaic Panels Combined with Energy Storage in a Residential Building: An Economic Analysis

2018 ◽  
Vol 10 (9) ◽  
pp. 3117 ◽  
Author(s):  
Federica Cucchiella ◽  
Idiano D’Adamo ◽  
Massimo Gastaldi ◽  
Vincenzo Stornelli
Keyword(s):  
Energy Storage ◽  
Net Present Value ◽  
Storage System ◽  
Residential Building ◽  
Weather Conditions ◽  
Energy Storage System ◽  
Economic Feasibility ◽  
Pv System ◽  
Pv Systems ◽  
Profitability Analysis

Renewable energy is a wide topic in environmental engineering and management science. Photovoltaic (PV) power has had great interest and growth in recent years. The energy produced by the PV system is intermittent and it depends on the weather conditions, presenting lower levels of production than other renewable resources (RESs). The economic feasibility of PV systems is linked typically to the share of self-consumption in a developed market and consequently, energy storage system (ESS) can be a solution to increase this share. This paper proposes an economic feasibility of residential lead-acid ESS combined with PV panels and the assumptions at which these systems become economically viable. The profitability analysis is conducted on the base of the Discounted Cash Flow (DCF) method and the index used is Net Present Value (NPV). The analysis evaluates several scenarios concerning a 3-kW plant located in a residential building in a PV developed market (Italy). It is determined by combinations of the following critical variables: levels of insolation, electricity purchase prices, electricity sales prices, investment costs of PV systems, specific tax deduction of PV systems, size of batteries, investment costs of ESS, lifetime of a battery, increases of self-consumption following the adoption of an ESS, and subsidies of ESS. Results show that the increase of the share of self-consumption is the main critical variable and consequently, the break-even point (BEP) analysis defines the case-studies in which the profitability is verified.

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