Average Performance Ratio Research Articles

Experimental studies on photovoltaic module temperature reduction using eutectic cold phase change material

An increase in Photovoltaic (PV) module temperature (TPV) affects the photoconversion efficiency (PCE). Annual TPV loss accounts higher than other losses in the PV system for hot climatic conditions. The main objective of this work is to introduce a novel passive Cold-PCM (C-PCM) to reduce the TPV. Commercial PCM’s are more expensive than a eutectic PCM. In this work, Lauryl alcohol and Ethyl alcohol are mixed in a ratio of 75:25 to form a eutectic mixture. The prepared eutectic mixture is having a melting temperature and latent heat of fusion of 21.75 °C and 199 J/g, respectively. Furthermore, C-PCM containers with 3-cm and 5-cm thickness are attached at the back surface of the PV module. It is observed that the 5-cm container exhibits higher heat transfer, which subsequently resulted in TPV reduction at a maximum of 10.3 °C. This decrease in TPV, enhanced the average voltage profile by 2.85%, thereby the average output power is also boosted by 2.8%. Consequently, this eutectic PCM can improve the average performance ratio, electrical efficiency and capacity utilization factor of the PV module by 72.63%, 10.09% and 19.41%, respectively. Thus the experimental results revealed that C-PCM could be a potential replacement to H-PCM for cooling down the TPV.

Experimental identification of effects of using dual airflow path on the performance of roof-type BAPV system

Photovoltaic (PV) modules attached to the building exterior have a problem with efficiency reduction due to temperature increase of the modules. To minimize the temperature increase of the PV modules, this study proposes a passive cooling technology that can improve the natural cooling performance by creating dual airflow paths for the building applied photovoltaic (BAPV) system. To experimentally verify this natural cooling technology (NCT), a BAPV system with the NCT and a conventional BAPV system of the same capacity were constructed, and their power-generation performances based on the three-month experimental results in a cold weather season were compared under the same environmental conditions. The BAPV system with the NCT on average generated 4.5% more power than the conventional BAPV system. The performance ratio (PR) analysis showed that the average PR value of the BAPV system with the NCT was 87.1%, which was approximately 5.5% higher than that of the conventional BAPV system. Results suggest that the proposed NCT improved the airflow on the backside of the PV modules and supplied fresh air to all of them, and hence, it improved the cooling performance and induced relatively lower module temperatures. A correlation between the electric power generated and the solar irradiance was derived for each system.

Operational Performance and Degradation of PV Systems Consisting of Six Technologies in Three Climates

In Indonesia, the solar photovoltaic (PV) market is rapidly growing. However, studies on the outdoor performance of PV systems in this tropical rainforest country is lacking. In this work, we compare the performance of PV systems in Indonesia with PV systems in Australia (arid, desert, hot) and Italy (temperate, dry summer, hot summer). Monitoring data from 2008 to 2019, ranging from two to nine years, from fifteen PV systems of six technologies were analyzed. The performance of the PV systems was presented using their performance ratio (PR) and performance loss rate (PLR). PR was calculated using IEC standard 61724, and PLR was calculated using seasonal and trend decomposition, applying locally weighted scatterplot smoothing (STL decomposition) and the year-on-year approach from NREL/RdTools. The results showed that the CIGS (copper indium gallium selenide) system had the highest average PR value of 0.88 ± 0.04. The lowest average PR was found in the a-Si (amorphous silicon) PV systems (0.78 ± 0.05). The p-Si (polycrystalline silicon) systems in the Cfb (temperate, no dry season, warm summer) climate of Italy had a higher average PR of 0.84 than those operated in climates BWh (arid, desert, hot) of Australia and Af (tropical, rainforest) of Indonesia, with the same value of 0.81. The p-Si systems showed the lowest PLR, with a value of −0.6%/year. The fastest degradation was experienced by a-Si modules at −1.58%/year. The methodological differences in the calculation of PLR using both tested approaches resulted in a significant difference in the degradation value, which demands standardization of the term and calculation methodology.

Study of a Hybrid Solar Absorption-Cooling and Flash-Desalination System

In this work, the analysis of a hybrid LiBr/H2O absorption-cooling and flash-desalination system, using solar thermal energy as heat source, is presented. An absorption open-cycle with three pressure levels is used in combination with a single-stage flash-desalination process to use the coolant as product water, resulting in an increase in cooling and desalination efficiency. For the application, a 20-room coastal hotel complex in San Felipe, Baja California, Mexico, is taken as a case study and the sizing of the solar collection and storage system is carried out for the operation of the proposed hybrid system, during the summer operative period. The operational dynamics during the week with the highest ambient temperatures are presented. The dimensioning of the solar collector’s area and the energy storage resulted in a collection area of 620 m2 with 30 m3, respectively, reaching a solar fraction of 69%. The absorption-cooling subprocess showed an increase of 13.88% in the average coefficient of performance (COP) compared to conventional LiBr/H2O absorption systems. Also, considering that the system provides cooling and desalination simultaneously, the average COPG is 1.64, which is 2.27 times higher than the COP of conventional LiBr/H2O single-effect absorption units. During the critical week, the system presented a desalinated water production of 16.94 m3 with an average performance ratio (PR) of 0.83, while the average daily water production was 2406 kg/day; enough to satisfy the daily water requirements of four people in a coastal hotel in Mexico or to cover the basic services of 24 people according to the World Health Organization.

Thermal impact on the performance ratio of photovoltaic systems: A case study of 8000 photovoltaic installations

Investigating the thermal impact including the fluctuations of the solar irradiance and ambient temperature of photovoltaic (PV) systems is a topic of great interest by industry and policymakers, due to the limited case studies reported so far by the PV research community. Therefore, this article presents the analysis of 8000 PV systems distributed across England using the well-known metric, monthly performance ratio (PR). The PV systems were operated over five years, while the PR is calculated using the newly developed model by the US national renewable energy laboratory (NREL). Remarkably, it was found that the average monthly PR for all examined PV systems is equal to 85.74%, where the Midlands region in the UK has the highest monthly PR of 88.12%. We have also investigated the seasonal thermal impact on the performance of PV systems, where it was concluded that Spring and Summer seasons intend to have higher monthly PR compared to Autumn and Winter. Finally, a detailed experiment of three different PV modules affected by various hotspots, including cell-based and string-based, will be comprehensively discussed.

Performance analysis of a 10 MWp utility scale grid-connected canal-top photovoltaic power plant under Indian climatic conditions

Photovoltaic modules installed on water bodies save large land areas but climatic conditions for such solar power plants, are different due to their proximity to flowing water.Thus it is important to study the performance of a canal-top solar PV plant for its reliable operation. In the present study, energetic, exergetic performance and reliability analysis of a 10 MWp grid-connected canal-top PV plant, is studied using more than 2 years data. The average monthly performance ratio, system efficiency and exergy efficiency of the plant, are found to be 0.78, 11.90% and 12.03%, respectively. PV degradation rate is found to be higher than land based power plants. The average monthly exergy efficiency, useful thermal exergy convective heat transfer loss and exergy destruction during monitoring period, are found to be 12.03%, 18.32%, 1% and 58.65%, respectively. The performance of present plant is found to be slightly lower than land based PV plants. The possible solutions to improve output power generation by canal-top PV plants are discussed. The water saved due to reduced water evaporation is found to be about 95 million litres per year.Further follow up research areas are identified to enhance the reliability of such power plants installed over water bodies.

Performance Analyses of 15 kW Grid-Tied Photo Voltaic Solar System Type under Baghdad city climate

The performance analyses of 15 kWp (kW peak) Grid -Tied solar PV system (that considered first of its type) implemented at the Training and Energy Research Center Subsidiary of Iraqi Ministry of Electricity in Baghdad city has been achieved. The system consists of 72 modules arranged in 6 strings were each string contains 12 modules connected in series to increase the voltage output while these strings connected in parallel to increase the current output. According to the observed duration, the reference daily yields, array daily yields and final daily yields of this system were (5.9, 4.56, 4.4) kWh/kWp/day respectively. The energy yield was 1585 kWh/kWp/year while the annual total solar irradiation received by solar array system was 1986.4kWh/m2. The average power losses per day of array, system losses and overall losses were (1.38, 0.15, 1.53) kWh/kWp/day respectively. The average capacity factor and performance ratio per year were 18.4% and 75.5% respectively. These results highlighted the performance analyses of this PV solar system located in Baghdad city. The performance can be considered as good and significant comparing with other world PV solar stations.

Experimental study of a novel solar multi-effect distillation unit using alternate storage tanks

Abstract In recent years, the use of solar energy has been growing exponentially and applied in a wider range of applications; one of the important applications for using solar energy is water desalination. The current work investigates the proof of concept experimental setup for a novel solar multi-effect distillation (MED) using alternate storage tanks. The experimental setup consists of a MED unit, two thermal storage tanks, and a solar collector. One storage tank is used as a charging tank while the other tank is used as a discharging tank. This unique dual-tank system stores the thermal energy to be used later in the MED unit, which improves the control of the water mass flow rate and water temperature throughout the MED process. The peak temperature achieved every day in the charging tank determines the MED production capacity. This system is designed for the tanks to alternate roles every 24 hours. The testing of this design was carried out during May 2019 in Saudi Arabia. The experimental results prove the novel concept design to work efficiently providing an average production rate of about 21 kg/day with total solar collector area of 2.7 m2 and average daily performance ratio of 2.5.

Performance analysis and investigations of grid-connected Solar Power Park in Kurnool, South India

The Government of India had initially aimed at an installed capacity of 20 GW solar PV power generation by 2022. However, India has 29.41 GW of solar photovoltaic (PV) plants as of now, which shows that the target is achieved three years ahead of schedule. Kurnool solar power park is one of the largest solar parks in India, receiving an excellent average solar radiation of 5.5–6.0 kWh/m2. As part of this project, a 50 MW solar photovoltaic system has been installed at Kurnool. This paper determines the performance parameters for analysis. The system was monitored from April 2018 to March 2019. The performance ratio varied between 75% and 83%, giving an annual average performance ratio of 79.94%. The capacity utilization factor varied between 18.90% and 29.34%, giving an annual average capacity utilization factor of 24.65%. The gain of modules with single-axis tracking system is compared with the fixed-tilt angle system. It is found that the single-axis tracking system improves the performance of the plant.

Performance and economic viability assessment of a 50 KWp rooftop solar photovoltaic system

Green energy is a global consensus to cope with increasing energy needs. Recognising this fact, the Government of India is expecting 40% of the demand to be fulfilled through rooftop solar plants by 2022. As a result, in many metropolitan regions, government and non-government organisations installed rooftop Solar Photovoltaic (SPV) systems and the energy produced is consumed for their usage. To contribute to this universal mission of energy conservation, The ICFAI University, Jaipur, had taken a significant step by installing a 50 kWp SPV system on its campus. This paper presents the performance assessment and economic feasibility of the SPV system which is monitored between January 2018 and June 2018. The energy production of the plant at 34,476.64 kWh recorded during the period. The array, final, and reference yields are perceived to vary from 2.7 to 5.04 kWh/kW/day, 2.45 to 4.73 kWh/kW/day, and 3.22 to 7.4 kWh/kW/day respectively. The monthly average daily performance ratio (PR) and capacity utilisation factor (CUF) measured amid 16.39-76.97% and 10.23-19.71 respectively. To investigate the pecuniary feasibility of the venture, the net present value (NPV), Profitability Index (PI), Internal Rate of Return (IRR) and Payback Period are used for different discount and subsidy rates.

Performance and economic viability assessment of a 50 KWp rooftop solar photovoltaic system

Green energy is a global consensus to cope with increasing energy needs. Recognising this fact, the Government of India is expecting 40% of the demand to be fulfilled through rooftop solar plants by 2022. As a result, in many metropolitan regions, government and non-government organisations installed rooftop Solar Photovoltaic (SPV) systems and the energy produced is consumed for their usage. To contribute to this universal mission of energy conservation, The ICFAI University, Jaipur, had taken a significant step by installing a 50 kWp SPV system on its campus. This paper presents the performance assessment and economic feasibility of the SPV system which is monitored between January 2018 and June 2018. The energy production of the plant at 34,476.64 kWh recorded during the period. The array, final, and reference yields are perceived to vary from 2.7 to 5.04 kWh/kW/day, 2.45 to 4.73 kWh/kW/day, and 3.22 to 7.4 kWh/kW/day respectively. The monthly average daily performance ratio (PR) and capacity utilisation factor (CUF) measured amid 16.39-76.97% and 10.23-19.71 respectively. To investigate the pecuniary feasibility of the venture, the net present value (NPV), Profitability Index (PI), Internal Rate of Return (IRR) and Payback Period are used for different discount and subsidy rates.

Smart Micro-Grid Performance using Renewable Energy

The aim of this research is to determine the performance of PV panels, wind turbines, battery storage and power imported from the grid to the system which will ensure a reliable energy supply, as well as the technical feasibility of a smart microgrid system. Indonesia’s renewable energy potential for electricity reaches 443 GW, where solar energy is the largest potential, namely 4.8 KWh m–2 or equivalent to 112 000 GWp, but only 10 MWp has been utilized. The most basic problem in this system, namely, the uncertainty of wind energy and solar energy, one of the most vital factors in the optimal size of a renewable energy-based smart microgrid system is the reliability of the system being built. The method used in this research is to collect data on the availability of wind energy and solar energy as well as load analysis on the smart microgrid system. As a result, the resulting power output was 6.2 MWh during the experiment. The highest average Performance Ratio (PR) of the solar energy power generation system, namely 77 % in February 2020. Optimized with Battery Life (OBL) model produces a power output of 102.4 kWh and has an overall system efficiency of 81.92 %.

Low-temperature multiple-effect desalination/organic Rankine cycle system with a novel integration for fresh water and electrical energy production

This paper presents a novel energetic integration of a Multiple Effect Thermal Desalination System (MED) and an Organic Rankine Cycle (ORC) for simultaneous production of potable water and electrical energy, using low-temperature energetic sources. The thermal energy required for the system's operation is supplied by the MED's evaporator, while the ORC is activated using a fraction of the latent heat of condensation of the water vapor produced in the first effect of the MED. By doing this, the production of water in the first stage of the desalination system increases and, thus, the final production of distillate also increases. A simulation and validation of the proposal was conducted. The MED/ORC system has a 3.95% increase on the average Performance Ratio when the electrical energy production increases in 10 kW, presenting only a 1.57% increase on the total heat transfer area. MED/ORC system with an electrical energy production of 50 kW is 22% more efficient in water desalination than a MED system without integration, while requiring only 6.9% more heat transfer area. The results show that the MED/ORC energetic integration studied benefits both the final production of desalinized water, and the MED's efficiency without considerably increasing the required heat transfer area.

Performance evaluation of building-integrated photovoltaic systems for residential buildings in southern India

The integration of photovoltaic modules into the building structure is a challenging task with respect to power generation of PV module and the effect of incident solar radiation. The performance of building integrated photovoltaic (BIPV) modules varies depending upon the orientation and azimuth angle of the building. In this work, the year-round performance and economic feasibility analysis of grid-connected building-integrated photovoltaic (GBIPV) modules is reported for the hot and humid climatic regional condition at Kovilpatti (9°10′0′′N, 77°52′0′′E), Tamil Nadu, India. The appropriate mounting structures are provided, to experimentally simulate the performance of GBIPV modules at various orientations and inclination angles (0° to 90°). The result indicated that the optimum orientation for installation of BIPV modules in the façade and walls is found to be east while that for a pitched roof south orientation is recommended. The overall average annual performance ratio, capacity utilisation factor, array capture loss and system losses are found to be 0.83, 23%, 0.07 (h/day), and 0.17 (h/day), respectively. In addition, the economic feasibility of grid connected PV system for residential buildings in Tamil Nadu, India is analysed using HOMER by incorporating both a net metering process and electricity tariff. Practical application: Grid-connected building-integrated photovoltaic system has many benefits and barriers by being installed and integrated into the building structure. The application of GBIPV in building structures and its orientation of installation needs to be optimised before installing into buildings. This study will assist architects and wider community to design buildings facades and roofs with GBIPV system which are more aesthetic and account for noise protection and thermal insulation in the region of equatorial climate zones. By adding as shading devices, they can reduce the need for artificial lighting, and moderate heating or cooling load of the buildings.

Field Analysis of three different silicon-based Technologies in Composite Climate Condition – Part II – Seasonal assessment and performance degradation rates using statistical tools

This paper is an extension study to the ‘Field Analysis of three different Silicon-based Technologies in Composite Climate Condition’ wherein, monthly average performance ratio, temperature corrected performance ratio, series resistance and effective peak power of multi-crystalline (mc-si), heterojunction with intrinsic thin layer (HIT) and amorphous silicon (a-si) based photovoltaic modules for three years were presented. The present study attempts to investigate seasonal performance and determine the degradation rates using three statistical tools, i.e. linear regression, classical seasonal decomposition (CSD), and locally weighted scatterplot smoothing (LOESS) on normalized performance ratio and normalized efficiency for three years. Further, comparative analysis of nine PV modules, i.e. three modules of each technology, and sensitivity analysis of solar irradiance and module temperature on performance ratio have been evaluated. The degradation rates are found to be 1.24%/year, 1.16%/year and 1.16%/year for a-si modules, 0.14%/year, 0.56%/year and 0.11%/year for HIT modules and 1.50%/year, 0.82%/year and 1.46%/year for mc-si modules using linear regression, CSD and LOESS analysis respectively. The average efficiency is found to be 5.17% for a-si, 15.40% for HIT and 10.78% of mc-si modules. Furthermore, the performance of these module technologies during particular season after three years of outdoor operation has also been assessed.

Effect of Irradiance Measurement Sensors on the Performance Ratio of Photovoltaic Power Plant Under Real Operating Conditions: An Experimental Assessment in Turkey

The performance analysis of photovoltaic (PV) plants plays an important role in making investment decisions, creating more efficient designs, and in the operation and maintenance decisions in new plants. In addition, performance analysis provides a way to identify real-time operational problems and allows comparisons among different PV plants. Performance of PV plants can be indexed with many parameters, but service providers are giving energy guarantees according to their performance ratio (PR). There are many factors that affect PR, such as irradiation, temperature, wind speed, humidity and soiling. But, the most important factors affecting PR are irradiation and temperature. Hence, both the irradiation and the temperature must be measured correctly. Solar irradiation is usually measured with a pyranometer or reference cell. However, there are differences between the obtained data from these two sensors, which affects the PR significantly. In this study, the PR of an MW PV plant installed in Turkey was investigated. Two types of irradiation sensors (pyranometer and reference cells) and PVGIS program were used. The data were collected every 5 min during 1 year. The data passed through quality control and filtered process and some improper values were removed from the row data set. In addition, new data were written instead of the missing data. PR was calculated by using conventional and corrected method. As a result, the average annual PR is determined to be 81.05%, 79.04% and 78.96% and the corrected PR is determined to be 83.69%, 82.48% and 80.87% using the reference cell, pyranometer and PVGIS program, respectively.

Performance assessment of 20.4 kW eco-house grid-connected PV plant in Oman

ABSTRACT The aim of this article is to analyse the performance of the Photovoltaic (PV) and to study the effect of soiling on the energy generation under Muscat environmental conditions. The generated energy is consumed in the eco-house, and the access energy is fed back to the electric grid. Two-ways metre was used to record the energy taken from the grid or fed back to the grid. The system was monitored from December 2014 until today. Various performance parameters of the plant were evaluated which include system efficiency, performance ratio (PR), capacity factor (CF) and different types of PV system losses and yields. The annual average values of recorded ambient temperature and solar radiation were 32°C and 482 W/m2, respectively. The total annual energy produced was 23,595 kWh, whereas the annual average daily reference yield, array yield and final yield were 5.59, 3.78 and 3.64 kWh/kWP/day, respectively. The annual average daily PR and CF were 0.67 and 0.15, respectively, while the annual average system efficiency was 10.3%. Furthermore, the annual average daily capture, system and cell temperature losses were 1.82, 0.14 and 2.95 h/day,respectively, with a small reduction in energy production when modules left uncleaned.

Performance analysis and energy metrics of grid-connected photovoltaic systems

The performance of two co-located grid-connected photovoltaic (PV) systems comprising polycrystalline silicon (p-Si) and copper indium selenium (CIS) arrays are analyzed in this work. The measured and simulated performances are compared with an objective to study the suitability of the technology in the real hot and humid climatic conditions of Tamil Nadu, Southern India. The parameters used for the performance evaluation are array yield, final yield, PV efficiency, performance ratio and capacity utilization factor. The year-round performances of both the photovoltaic (PV) systems are predicted by PVsyst software using measured weather data at the site and compared with that of the actual measured results. The normalized measured annual energy delivered to the grid is 1536.9 kWh and 1698.4 kWh for p-Si and CIS PV systems respectively. The yearly average performance ratio is 78.48% for p-Si and 86.73% for CIS while the capacity utilization factor varies from 17.99% (for p-Si) to 19.57% (for CIS) respectively. Also, high capture losses are observed in the p-Si PV plant than that in the CIS PV plant. The performance indices of the PV systems are compared with that of the similar capacity PV systems situated at other locations. Further, embodied energy, energy payback time (EPBT), energy production factor (EPF), and life cycle conversion efficiency (LCCE) of the PV systems have also been estimated. The energy yield of CIS array is found to be 7.61% more in comparison to p-Si array round the year favoring its suitability for potentially, sites with a similar climate.

A novel design for solar integrated multi-effect distillation driven by sensible heat and alternate storage tanks

This article presents a novel Multi-Effect Distillation (MED) system which utilizes indirect brine heating such that a medium fluid is circulated through the concentrating solar collectors and store the energy in a charging tank. Each “effect” of a MED unit is a chamber in which cool feedwater brine is sprayed onto heat exchangers, partially evaporating the brine. The vapors and heated brine serve to pass thermal energy to subsequent effects. One of the uniqueness of the design is that the heat exchanger in the first effect of the system receives a flow of hot medium fluid, such that sensible heat is passed to the incoming feedwater. The thermal storage system consists of two identical, insulated tanks, each with sufficient volume to supply the medium fluid for a full day. A dynamic mathematical model is developed and simulated with four MED stages (“effects”). The number of concentrated solar arrays are optimized to generate a peak of 2200 metric ton per day of distilled water, with indispensable total array area of 92,000 square meter. The average daily performance ratio is 2, and the average specific thermal energy consumption is 1140 kJ per kg.

Seasonal Performance Comparison of Four Electrical Models of Monocrystalline PV Module Operating in a Harsh Environment

To accurately predict the performance of a photovoltaic (PV) system, it is necessary to assess the effectiveness and accuracy of the methods used in modeling PV cells. This paper presents and analyzes the performance of a monocrystalline PV module (SYP80S-M) installed in outdoor operation conditions in Adrar, Algeria. The monthly experimental results are compared with those calculated by four different methods: single(fourand five-parameter) and double-diode (seven-parameter) model. The monthly average performance ratio, efficiency, and output energy were calculated and compared based on year data. Statistical analysis shows good correspondence of all models with the experimental monthly average energy data. However, the results reveal that the double-diode seven-parameter model outperforms the other models with 99.55% forecasting accuracy. In general, the accuracy of the models increases during hot months with the root-mean-square error (RMSE) varying between 2.2 and 4.4 and mean bias error (MBE) lower than 2.1, while RMSE values are higher at 4.5 and those of MBE exceed 0.37 for the cold months.