Floating Photovoltaic System Research Articles

Potential of usage of the floating photovoltaic systems on natural and artificial lakes in the Republic of Serbia

The Republic of Serbia has a significant potential for the electricity production from solar energy, namely the floating photovoltaic (PV) systems, which are not exploited enough. Although there is a large interest in floating photovoltaic systems (FPVS) worldwide, studies related to the assessment of FPVS potential in this part of Europe have not been performed yet. This paper investigates, for the first time, the possibility of implementation of the FPVS on the six largest Serbian lakes and demonstrates the impact of geographical location on the energy output of the FPVS for the selected locations. The possibility of implementation is studied by simulating the energy output of FPVS using "PVGIS" tool. Energy production from the proposed FPVS, for selected locations, is discussed on a monthly and yearly basis. Installment of the FPVS on these water bodies can produce up to 8959 kWh of energy, while saves 164·106m3/year of water from evaporation at the same time. In addition, the annual reduction of carbon dioxide emissions was analyzed and found to be up to 6.34 tons per year, which further implies with carbon credit potential of up to 9741 € in 20 years period. Drawn conclusions provides better understanding of FPVS and their applicability in the Republic of Serbia to ensure a sustainable, ecological friendly, secure and reliable supply of green energy, and further the used approach can be easily applied in other countries with similar geographical characteristics.

Analyzing and evaluating floating PV systems in relation to traditional PV systems

The various benefits of floating photovoltaic technology, a relatively new kind of energy generation, have piqued the interest of many people (FPVT). FPVT technology not only helps to lessen water loss due to evaporation, but it also helps to increase energy production. Science can't progress without the analysis of mechanical and electrical systems. Many researchers have looked at FPVT systems from different angles. This article undertakes a logical investigation and provides a thorough summary of the state of the art, elaborating on the numerous features and components of FPVT systems as a means of producing electricity. The advantages and disadvantages of each type have been compared in detail. A common way of capturing solar energy for use in electrical generation is the installation of solar arrays on the roof of a structure. However, although most homes only need 5–20 kW, most enterprises require 100 kW or more. On average, floating solar panels produce 11 percent more energy than their ground-based counterparts. Approximately 40% of the water in open reservoirs is lost to evaporation, according to studies. Covering only 30% of the water's surface can reduce evaporation by 49%. At 104 GW, the solar panel market will see a compound annual growth rate of 6%. Global photovoltaic capacity climbed by 27% in 2018, reaching 512 GW. This represents about 55% of the total capacity. This study also predicts that the FPVT system will help spur a 7.38 percent increase in solar technology, which is equal to 485.4 GW of additional installed electricity around the world.

Economic comparison of floating photovoltaic systems with tracking systems and active cooling in a Mediterranean water basin

Floating Photovoltaic (FPV) modules are installed on water surface to reduce land use. This original solution, potentially deployable on hydropower and aquaculture basins as well, can benefit of enhanced cooling due to the proximity to water. Thanks to this natural effect, FPV modules can work at higher operating efficiencies than ground-based (GPV) modules. However, because of the relatively young age, FPV still requires higher installation costs than GPV. This study investigates the economic competitiveness of GPV and FPV in terms of energy performance and total costs. Different PV system solutions are economically evaluated on the basis of three key figures, namely the capital costs (CAPEX), the operation and maintenance costs (OPEX) and the power generation costs (LCOE). An economic ranking is created based on the comparative analysis of these three key figures.The crucial point in the proposed economic model is that the revenues resulting from the reduced evaporations are considered as well. Every year, indeed, a significant volume of water can be preserved thanks to the shading effect of FPV modules. This water can be used for various purposes, increasing the overall revenues of the FPV system. In addition, the present LCOE calculations also take into account the performance enhancements that could be achieved through the installation of active cooling systems.In light of the expected economy of scale, a sensitivity analysis of the LCOE is carried out to account potential reductions in the capital cost of FPVs. This is done by analyzing the energy and economic performance of various FPV designs on a water basin in Southern Italy. The results demonstrate that, reducing the CAPEX of the FPV by 30 %, a nearly 20 % reduction in LCOE can be obtained compared to the reference GPV system.

A novel approach suggestion for assessing the impact of topographic shading on the estimation of the floating photovoltaic technical potential

This study presents a novel approach for the implementation of floating photovoltaic (FPV) systems at the Ayvalı hydroelectric power plant (HPP) in Türkiye. The method proposed in this study accounts for dynamic changes in water levels to accurately calculate the shading effects induced by topography. First, the minimum reservoir surface for the FPV system was calculated using remote sensing (RS). The minimum reservoir surface area, which was determined as 504.69 ha using 60 Sentinel-2 satellite images, was calculated using machine learning algorithms on the Google Earth Engine (GEE) platform, support vector machines (SVM) and automatic water extraction index (AWEI). In the second stage, new digital elevation model (DEM) maps were produced by overlapping monthly changes in water height with ALOS PALSAR data and solar analysis was performed on them. An annual global horizontal irradiance (GHI) map was produced using these maps, and it was divided into five classes to emphasize differences in production potential. The results revealed that 1083.45 GWh of electricity can be produced annually by installing FPV in very high and high potential areas. However, as the moderate, low, and very low regions represent only 5.02% of the reservoir surface and there is a 1.68-fold difference in production potential between the highest and lowest areas due to topography-induced shading near the coastline, it was concluded that FPV installation would not be efficient in those regions. This study highlights the significance of incorporating topography-induced shading and emphasizes the importance of employing RS and geographic information system (GIS) techniques to achieve this objective.

Front-End Current-Fed High Gain Isolated Converter with Flexible Power Point Tracking for Floating PV System

Front-End Current-Fed High Gain Isolated Converter with Flexible Power Point Tracking for Floating PV System

Do the Dam Project—Evaluating floating solar photovoltaic and energy storage at Inanda Dam within eThekwini Municipality, South Africa

South Africa’s electricity generation plant portfolio includes several aged units, resulting in frequent breakdowns, electricity shortages and load shedding. This study evaluates the feasibility of generating electricity at the Inanda Dam located within eThekwini Municipality of South Africa by installing a floating photovoltaic (FPV) system. The Inanda Dam provides water for many local communities, and load shedding affects pumping operations and disrupts the continuity of water supply. Therefore, the study further evaluates the plausibility of coupling energy storage/alternate generation with the FPV system to provide enough electricity for pumping operations during an outage. In addition, this study evaluates the financial benefits to the municipality resulting from the project implementation. The Hybrid Optimization Model for Multiple Energy Resources (HOMER) software tool was utilised to conduct techno-economic analysis and optimise the size of system components to meet the load requirements while minimising the overall net present costs (NPC). Without limiting the dam usage space for FPV, the optimal FPV system size was 10 MWp to maintain the least NPC. However, with the generation system size larger than the water pumping demand, the excess solar energy generated can be exported back into the grid resulting in the municipality gaining $1 015 473 in the first year of operation. Incorporating battery energy storage or a diesel generator can mitigate load shedding at the pumping site. However, battery energy storage requires significantly more capital upfront and produces a nil financial investment return compared to the diesel generator option, making it the least preferred option to implement.

An assessment of the economic feasibility of the floating PV technology in Aotearoa–New Zealand

Electricity generation from utility-scale solar facilities is projected to grow to between 5 and 16 TWh by 2050 in Aotearoa–New Zealand. The floating photovoltaic (FPV) technology is considered a viable option for the country, because of the good solar resource at existing hydropower schemes. This paper aims to inform the understanding of the economic feasibility of FPV systems through the analysis of specific cases – Maraetai Dam and Lake Tekapo. To do so, the solar resource and FPV outputs are obtained through the modelling of Solargis and using industry standard technical specification. As well as the normal uncertainties associated with (potential) FPV performance evaluations, the influence of water temperature is also considered. The overall FPV output is estimated to be between 1,115 and 1,497 kWh/kWp. Using available Engineering, Procurement and Construction (EPC) costs, the levelized cost of energy (LCOE) metric, for a 10 MW installation, is determined to be between NZ$176 and NZ$237 per MWh, with total electricity generation over 25 years between 263 and 353 GWh. In order to reach the required LCOE value of less than NZ$100/MWh for utility scale generation, the EPC costs will have to be reduced by a factor of 2 to around NZ$1,500/kWp.

Floating Photovoltaic Systems Coupled with Pumped Hydroplants under Day-Ahead Electricity Market Conditions: Parametric Analysis

The intermittent nature of the solar resource together with the fluctuating energy demand of the day-ahead electricity market requires the use of efficient long-term energy storage systems. The pumped hydroelectric storage (PHS) power plant has demonstrated its technical and commercial viability as a large-scale energy storage technology. The objective of this paper is to analyse the parameters that influence the mode of operation in conjunction with a floating photovoltaic (FPV) power plant under day-ahead electricity market conditions. This work proposes the analysis of two parameters: the size of the FPV power plant and the total process efficiency of the PHS power plant. Five FPV plant sizes are analysed: 50% (S1), 100% (S2), 150% (S3), 350% (S4) and 450% (S5) of the PHS plant. The values of the total process efficiency parameter analysed are as follows: 0.77 for old PHS plants, and 0.85 for more modern plants. The number of daily operating hours of the PHS plant is 4 h. These 4 h of operation correspond to the highest prices on the electricity market. The framework of the study is the Iberian electricity market and the Alto Rabagão dam (Portugal). Different operating scenarios are considered to identify the optimal size of the FPV power plant. Based on the measured data on climatic conditions, an algorithm is designed to estimate the energy production for different sizes of FPV plants. If the total process efficiency is 0.85, the joint operation of both plants with FPV plant sizes S2 and S3 yields a slightly higher economic benefit than the independent mode of operation. If the total process efficiency is 0.77, there is always a higher economic benefit in the independent operation mode, irrespective of the size of the FPV plant. However, the uncertainty of the solar resource estimation can lead to a higher economic benefit in the joint operation mode. Increasing the number of operating hours of the PHS plant above 4 h per day decreases the economic benefit of the joint operation mode, regardless of the total process efficiency parameter and the size of the FPV plant. As the number of operating hours increases, the economic benefit decreases. The results obtained reveal that the coupling of floating photovoltaic systems with pumped hydroelectric storage power plants is a cost-effective and reliable alternative to provide sustainable energy supply security under electricity market conditions. In summary, the purpose of this work is to facilitate decision making on the mode of operation of both power plants under electricity market conditions. The case studies allow to find the optimal answer to the following practical questions: What size does the FPV power plant have to be in order for both plants to be better adapted to the electricity market? What is the appropriate mode of operation of both plants? What is the economic benefit of changing the turbine pump of the PHS power plant? Finally, how does the installation of the FPV power plant affect the water volume of the upper reservoir of the PHS plant? Knowledge of these questions will facilitate the design of FPV power plants and the joint operation of both plants.

Assessment of the Potential of Installing Floating Photovoltaic Systems in Existing Water Reservoirs in Greece

Floating photovoltaics consists of a new and fast-growing technology worldwide. Installations of these novel green energy systems have not been developed so far in Greece. The aim of the current work is to investigate the potential of installing floating photovoltaic systems in Greek water bodies. The existing water reservoirs in Greece have been identified while their water surface that allows the installation of solar panels, the nominal power of the floating photovoltaics and the generated solar electricity have been estimated. The nominal power of floating photovoltaics which can be installed in the existing 128 water reservoirs in Greece covering 10% to 30% of their surface varies between 4.77 GWp to 14.31 GWp while the annual generated electricity at 6,435.2 GWh to 19,305.6 GWh corresponding at 12.40% to 37.20% of the total annual electricity consumption in the country. The annual water evaporation savings, due to installation of floating photovoltaics, have been calculated at 71.55 mil. M3 to 214.65 mil. M3 while the increased annual electricity gain at 321.76 GWh to 1,930.56 GWh. The results indicate that significant amounts of electricity can be generated with floating photovoltaics installed in water reservoirs in Greece. They could be useful to policy makers who are developing policies to achieve net zero carbon emissions by 2050 in Greece and to energy companies who are willing to invest in these novel green energy technologies.

Floating photovoltaic systems: photovoltaic cable submersion testing and potential impacts

Background: Floating photovoltaics (FPV) is an emerging technology that is gaining attention worldwide. However, little information is still available on its possible impacts in the aquatic ecosystems, as well as on the durability of its components. Therefore, this work intends to provide a contribution to this field, analysing possible obstacles that can compromise the performance of this technology, adding to an increase of its reliability and assessing possible impacts. The problem under study is related to the potential submersion of photovoltaic cables, that can lead to a degradation of its electrical insulation capabilities and, consequently, higher energy production losses and water contamination. Methods: In the present study, the submersion of photovoltaic cables (with two different insulation materials) in freshwater and artificial seawater was tested, in order to replicate real life conditions, when FPV systems are located in reservoirs or in the marine environment. Electrical insulation tests were carried out weekly to assess possible cable degradation, the physical-chemical characteristics of the water were also periodically monitored, complemented by analysis to detect traces of copper and microplastics in the water. Results: The results showed that the submersion of photovoltaic cables with rubber sheath in saltwater can lead to a cable accelerated degradation, with reduction of its electrical insulation and, consequently, copper release into the aquatic environment. Conclusions: The test results pointed a probable relationship between submersion of cables with rubber outer shell and water freezing temperatures and the occurrence of accelerated degradation of the cable insulation layer. Reduced insulation resistance values were measured in this cable type after the occurrence of such temperatures, both in salt and freshwater, the cable presented visible exterior degradation signs. For this case copper residues were detected in the water.

Desalination Plant for Irrigation Purposes Driven by an Inland Floating Photovoltaic System

In places where water and land are scarce it is vital to look for innovative solutions that can ensure water production for agricultural purposes. This study considers the treatment of water using desalination processes to meet the quality requirements needed for irrigation purposes in agriculture. As the water is stored in a pond, an inland floating photovoltaic (FPV) system is proposed to meet the desalination energy demand. This system would enable energy production without using additional land that could otherwise be used for agricultural purposes. The use of FPV technology also reduces water evaporation, thus avoiding unnecessary energy consumption. To generate enough electricity to treat 12,000 m3/day of water, using an electrodialysis reversal desalination plant, a 1.85 MWp FPV farm is proposed. The results indicate that this FPV farm would generate 3,005,828 kWh per year while avoiding the emission of 58,300 tons of CO2 and the evaporation of 159,950 m3 of water during its 25-year lifetime. Such systems allow higher renewable penetration in the energy mix and preserve the original use of the land.

How do rotifer communities respond to floating photovoltaic systems in the subsidence wetlands created by underground coal mining in China?

Along with the increasing demand for energy and pressure to reduce carbon emissions, floating photovoltaic (FPV) systems are increasingly built on the surface of water bodies with the aim to produce clean energy. However, little is known about how FPV systems influence freshwater ecosystems, e.g., their zooplankton communities. We investigated how rotifer communities responded to FPV systems in subsidence wetlands created by underground coal mining in the North China Plain. Diversity metrics of the rotifer communities were compared between wetlands with and without FPV systems. The density of rotifers was higher in wetlands without FPV systems. In contrast, rotifer diversity as represented by Shannon-Weiner and Pielou evenness indices was higher in the FPV-covered wetlands, while there was no difference in species richness between the two types of wetlands. Furthermore, community structures differed between the two types of wetlands, in large part reflecting differences in the relative abundance of five dominant species found in both types of wetlands. These differences in rotifer assemblages were in large part explainable from environmental changes caused by the FPV panels, notably reduced light availability and water temperature, leading to reduced phytoplankton production. These findings show that FPV systems cause major changes to rotifer communities in these subsidence wetlands and likely in wetlands more generally, and monitoring of the longer-term effects is recommended given the fundamental role of zooplankton in freshwater ecosystems.

Floating photovoltaic module temperature estimation: Modeling and comparison

As the power demand increases, photovoltaic (PV) energy evolves with time, and besides the traditional ground-mounted and roof-based PV systems, floating photovoltaic (FPV) systems have gained popularity due to higher efficiency from lower module temperatures and water evaporation reductions. This paper estimates and compares the temperature of the floating PV module using thermal, empirical, and computational fluid dynamics (CFD) models. The dynamic thermal model considers a three-level energy-balance equation for the FPV module. From that, a simplified thermal model has been developed, which requires fewer parameters and is easier to estimate the module temperature. Secondly, the least squares regression was used to generate the empirical model, resulting in the smallest possible root mean square error when comparing the observed and predicted values. Finally, the FPV system has been developed in the COMSOL environment for CFD analysis using the same heat transfer method. The estimated results from the models were compared with the actual data collected from a Brazilian site and the existing FPV and ground-mounted temperature models. The RMSE performance of the FPV models was comparable to that of the data obtained from an installed FPV system and performed much better than other similar FPV models and their ground-based counterparts.

Floating photovoltaics systems on water irrigation ponds: Technical potential and multi-benefits analysis

Floating photovoltaic systems (FPV) can be a more sustainable alternative for the energy transition than ground-mounted photovoltaic systems, as they avoid occupying useable land and the power generation is more distributed. This paper presents the first study that calculates the FPV technical potential at the province/municipality level, focusing on water irrigation ponds, which it is a novelty in the literature that usually focuses on large water infrastructures in a national approach. In the province of Jaén (Spain), more than 3000 ponds dedicated to agricultural irrigation have been identified and their surface area and location was obtained. The results, calculated for each pond, reveal that, in a conservative scenario, in which only 25% of their surface area is covered, a minimum of 490 MWp can be installed, which can provide 251% of the province agricultural electricity consumption and 27% of the total electricity needs. This analysis has also been performed at the municipal level, where all possible FPV plants have been aggregated and compared with consumption that would be covered at this scale. Furthermore, this technology brings additional benefits, as it avoids the occupation of 12 km2 of useable land, 8.8·106 m3/year of water evaporated, while creating more than 7000 jobs.

Performance analysis of polycrystalline floating photovoltaic array: The concept and prototype development for irrigation purpose

AbstractThe concept and design of the 2 kWp polycrystalline floating photovoltaic (PV) system for agricultural irrigation purposes are presented in this paper. The well‐known major advantage of the floating PV system is its installation in the presence of water, which leads to cooling of the PV system that improves its efficiency. In addition to that, the floating PV system reduces the wastage of cultivation area required for its installation, and also, it reduces evaporation of water (for 20% of float cover) by the factor of 22.23 cm/year. But the floating PV systems face some confrontations such as low electrical reliability and reduced life of the mechanical structure due to nearby water surface. As an attempt to overcome the above issues, a small‐scale floating PV system prototype in a water reservoir at Kothavadi village, Tamil Nadu, India has been developed. The system comprises of a floater, mechanical structure, PV module, supporting anchor, under water cable, and motor. The power generated out of this proposed system is utilized for pumping the water from a nearby bore well, and pumped water is stored in the same reservoir where the floating PV system is installed. The water in the reservoir can be used by the farmer for their necessity. In this study, the energy production (month by month) is monitored. Furthermore, the economic analysis and PV modeling have been performed along with some maintenance aspects. The study helps the scientists and engineers to comprehend the performance and commercial viability of floating PV for rural farmers. It is anticipated that this work will inspire and direct farmers to install a floating PV irrigation system as a perfect alternate for the conventional systems.

Photovoltaic Module Degradation Forecast Models for Onshore and Offshore Floating Systems

The degradation trend of photovoltaic modules depends on the technology, manufacturing techniques and climatic conditions of the site where they are installed. Longer useful life of the PV modules means that they will be able to produce much more energy than was used to build them; thus, extending the useful life of the modules is beneficial for the environment and increases the cost effectiveness of PVs. The problem of land use has prompted the development of agrivoltaic systems to exploit the same land both for the production of energy and for agriculture, and on water surfaces such as lakes and dams (floating PV). The exploitation of floating PV systems in onshore and offshore areas is currently under study. This constitutes an opportunity for which many factors must be taken into account; a fundamental aspect is the environmental impact, on which some recent studies have focused. Another aspect is the impact of the marine environment on PV system reliability and durability, due to the stress on operating conditions. The aim of this preliminary study is to evaluate the influence of the marine environment on the degradation trend of photovoltaic modules, based on existing models whose inputs are meteorological data from offshore locations. The results obtained from the application of a cumulative exposure model unexpectedly showed a lower degradation value in the offshore environment than on the mainland: −0.95% and −3% values of power decay, respectively. The absolute value of power decay in the onshore case is higher than the typical values because the used model has to be revised, as the empirical coefficients of the model have to be calculated according to the installation environment. The empirical coefficients used in the model were obtained in environmental conditions different from those under study. In the offshore case, the degradation estimated by the model does not take into account some environmental factors typical of the marine environment. Model adaptations calibrated with datasets of plants in environmental conditions similar to those analyzed would allow for greater accuracy in the results.

Economic Analysis of a Pumped Hydroelectric Storage-Integrated Floating PV System in the Day-Ahead Iberian Electricity Market

This study identifies the optimal operational strategy for floating photovoltaic power plants and pumped hydroelectric power plants in the day-ahead Iberian electricity market. Different operating scenarios were analysed based on forecast accuracy in addition to any deviations occurring in the day-ahead market, taking into account the rules of the electricity market and the technical operational limitations of both plants. These scenarios show the choice between the independent mode of operation and the joint mode of operation of both plants. Five scenarios have been studied, with upward and downward deviations of 5%, 10%, 25% and 50% considered. These scenarios can be classified into two groups. If there are deviation penalties, group 1; or without deviation penalties, group 2. Scenarios 3 and 4 belong to the first group and scenarios 1, 2 and 5 to the second group. In the scenarios of the first group, the price deviations are used, and in the scenarios of the second group, the marginal market price is used. The economic benefit of the scenarios with deviation penalties is obtained in the joint operation mode of both plants. Economic benefits of up to 35% are obtained. In contrast, in the scenarios where there are no deviation penalties, the independent mode of operation is the optimum. The reason for this is the low efficiency of the pumping process. In this case, economic benefits of 1.6% are obtained. This study can be used to guide the decision-making process in the operation of both plants in order to maximise the economic benefit.

Review of recent water photovoltaics development

Abstract Photovoltaic (PV) power generation plays an important role in the clean energy. Placing PV on water has therefore become an interesting alternative siting solution. In this paper, the floating photovoltaic system is divided into four categories: fixed pile photovoltaic system, floating photovoltaic system, floating platform system and floating photovoltaic tracking system and the principles, technologies and future challenges of PV systems on water will be reviewed. Other challenges encountered with water PV are discussed and future research directions are presented.

Effects of various inlet angle of wind and wave loads on floating photovoltaic system considering stress distributions

Solar energy is a promising renewable energy source for reducing greenhouse gases emissions and mitigating climate change. Floating photovoltaic (PV) systems have been widely installed, but severe wind and wave conditions have made their safety a critical issue. However, as the size of the floating PV system is large, it is difficult to evaluate the safety of the floating PV system in the experimental conditions. Thus, the safety judgment procedure was suggested considering various inlet angle of wind and wave loads and the stress distributions to judge the safety of the floating PV system. The numerical simulations were conducted to analyze the area-averaged drag coefficients of the solar panels and displacements of the floating bodies and were validated with experimental results. The wind loads on the first and last row of solar panel showed the higher values compared to another row of solar panel. Furthermore, the wave load varied the displacements of the floating PV system according to the wave direction and formations. Then, the forces obtained from numerical simulations were used as boundary conditions for finite element analysis. Under the conditions considered in this study, the junctions of the frame between the floating bodies and solar panels were found to have the highest stress around 150–298 MPa. Maintaining the stress at these junctions below the yield strength of the material should keep the unit floating PV system safe under wind and wave conditions at various inlet angles. Thus, floating PV system designers should consider this safety judgment procedure before they are installing floating PV in the field.

A study on bamboo as the alternative material for floating PV system structure

This paper presents the study of bamboo as an alternative material for structure of floating PV system. Bamboo is selected as it is used for traditional floating house structure by Indonesian people. Additionally, bamboo is a fast growing vegetation and it can be found easily here. To investigate its potential, the study includes the characteristics of bamboo material such as its the physics and mechanics, the application of bamboo as a structure material and subsequently the component of PV structure to analyse the feasibility of bamboo material as the floating PV structure. In the analysis, the following aspects are studied: floatation system, configuration and mooring configuration.