Floating Photovoltaic Research Articles

Wave-induced structural response analysis of the supporting frames for multiconnected offshore floating photovoltaic units installed in the inner harbor

In this study, a hydrodynamics-based structural response analysis procedure of supporting frames for multiconnected offshore floating photovoltaics (FPVs) is suggested. Based on the suggested simulation methodology, the dynamic behavioral characteristics of the system were investigated. First, rational mooring types for FPVs installed in the inner harbor were studied based on the analysis results. Subsequently, extensive parametric studies have been conducted to determine a rational design strategy for dynamic response mitigation. In this study, the effects of the initial configuration and axial stiffness of taut mooring lines, arrangement angles of FPV systems, and floater dimensions on the static and dynamic responses of supporting frames under irregular waves in the inner harbor were studied. The corner module in the multiconnected system showed critical responses among others, the investigation of which is required for safety evaluation. Furthermore, it was observed that the mooring stiffness governed the overall stiffness of the system, which was proportional to the mitigation of the dynamic responses. Finally, the unsupported length of the frame, which was defined by the floater size, was found to be the key parameter for the mitigation of structural responses.

Optimal site selection for floating photovoltaic systems based on Geographic Information Systems (GIS) and Multi-Criteria Decision Analysis (MCDA): a case study

ABSTRACT Solar energy is growing rapidly thanks to reduced implementation costs; European development plans foresee a significant increase in installed capacity in the coming years. In this scenario, new identifiable areas on water surfaces are needed. This would lead to the development of floating photovoltaic (FPV) systems, which would mitigate the environmental impacts of terrestrial installations. Therefore, it is necessary to develop and propose a methodology to identify suitable sites for the installation of such plants. This study is useful to demonstrate the potential benefits that can be achieved using the methods of GIS for the optimal siting of FPVs in combination with the use of MCDA in areas such as Sicily, which are characterised by high summer temperatures. Seven watersheds were studied and the best site for FPV allocation selected using MCDA is San Giovanni Dam.

How cool is floating PV? A state-of-the-art review of floating PV's potential gain and computational fluid dynamics modeling to find its root cause

The noticeable rise in electricity demand, environmental concerns, and the intense land burden has led to installing PV systems on water bodies to create floating photovoltaic (FPV). Of all market niches, FPV is the one developing the fastest. Along with some of its well-documented merits comes a claim that FPV modules operate at a lower temperature than their ground-mounted counterparts (GPVs). This claim is essential due to the performance loss of PV modules at high operating temperatures. Some literature claims that FPVs are so well-cooled that they maintain around 10% higher efficiencies. However, this cooling is poorly quantified, and the root cause remains unclear in the industry. In this paper, an extensive review of all the latest published literature and white paper advertisements was analyzed. The gains in energy yield coming from different root causes range from 0.11% to 31.29%! This proves the point of lack of clarity of potential gain of FPV. The paper then analyses four possible explanations for this cooling effect and its root causes. The FPV performance parameters are isolated and systematically investigated through physics-based finite element modeling. The impacts of wind velocity, wind direction, water temperature, relative humidity, air temperature, proximity to water, tilt angle, and others are evaluated and explained. The outcomes dictate that FPV is cooled largely through wind convection. But the increase in efficiency is below the anticipated values, ranging from 0.5% to 3%.

The development of floating solar farms on the surface of impounding reservoirs in Hong Kong

The initiative to develop Renewable Energy in Hong Kong was first addressed in the 2018 Policy Address and further elaborated in the ‘Hong Kong Climate Action Plan 2030+’. In October 2021, the Government of the HKSAR announced the new ‘Climate Action Plan 2050’ to strive to achieve carbon neutrality by 2050. In response, to promote the development of renewable energy, the Water Supplies Department (WSD) has undertaken studies and three pilot trials of floating photovoltaic (FPV) systems on the surfaces of Hong Kong’s reservoirs. With the successful implementation and operation of these pilot systems, the WSD is now embarking on the investigation and design of a large-scale 5-megawatt (MW) capacity floating solar farm (FSF) at Plover Cove Reservoir. Future studies will commence shortly to explore the feasibility of also implementing large-scale FSFs totalling 130 MW on other impounding reservoirs. The paper discusses some of the design issues and considerations including innovations/technology of FSFs which are specific to Hong Kong. These include the resilience of the FPV system to withstand severe typhoon conditions, environmental and water quality issues, and the proximity of nearby waterworks facilities for utilisation of the generated renewable energy.

Optimal Design of Bifacial Floating Photovoltaic System With Different Installation Azimuths

Considering the increasing interest in the realization of carbon-neutral and RE100 systems, and the expansion of the supply of renewable energy through large-scale floating photovoltaic systems (FPVs), this study designed large-scale bifacial FPVs for maximum power density. Moreover, the estimated power generation was compared and analyzed according to the installation methods of the conventional monofacial PV module facing south (Mono-S), bifacial PV module facing south (Bi-S), and bifacial PV module facing east and west (Bi-EW). Using the proposed design method, the power generation per unit area for FPVs was 17.87% to 36.08% higher than that of the conventional installation method. In addition, this method can contribute to gird stability by decreasing the peak power around noon and increasing power generation during low irradiation and can be applicable to marine photovoltaics(MPVs).

Floating photovoltaic pilot project at the Oostvoornse lake: Assessment of the water quality effects of three different system designs

Floating photovoltaics (FPV) is emerging as a promising renewable energy technology which enables the production of electricity on surface waters. While this technology could potentially make an important contribution to the energy transition, the current uncertainty about the water quality effects of FPV deployment poses a major barrier to FPV project development and implementation. In this study, we investigated the water quality effects of three distinctive FPV system designs, implemented as part of a 1-year pilot project at the Oostvoornse lake, the Netherlands. A water quality monitoring campaign was set up to monitor on a continuous basis a set of key water quality parameters, including light intensity, water temperature and dissolved oxygen concentration. The measurements were conducted below each of the three FPV systems and contrasted with reference measurements at open water adjacent to the systems. Our monitoring results show that of the water quality parameters considered, the impact of the FPV systems on light intensity was found to be most pronounced, with a light reduction between 73% and 100% relative to the reference measurements. We found limited evidence to corroborate that the FPV systems induced changes to the water temperature and dissolved oxygen concentration. However, it must be noted that this study took place under highly specific conditions due the limited size of the FPV pilot systems and the brackish water of the Oostvoornse lake. This means that the water quality effects reported here may not be representative for a larger scale application of the FPV designs, and may not be one-on-one transferable to other, non-brackish project locations elsewhere.

Hybrid Floating Photovoltaic - Hydropower Potential Utilization in Indonesia

Most countries mitigate climate alter impacts by deploying renewable energy to decarbonize their energy system. One of the emerging renewable energy options is the integration of floating photovoltaic (FPV) and hydropower. The FPV has higher efficiency and helps to reduce evaporation and offset hydropower production during the dry season. Conversely, hydropower can overcome intermittent solar production due to its flexibility. Our study aims to estimate the energy potentials from FPV plants and hydropower integrations in Indonesia. As result, the country has 5,807 potential reservoirs for FPV and 26 hydropower plants with a reservoir area with a potential utilization of more than 1 MW. Those sites are suitable for 3 GW floating power plants and 2.8 GW hydropower. And those sites can reduce CO2 emissions by 2,911,197 tonnes per year.

Benefits of pairing floating solar photovoltaics with hydropower reservoirs in Europe

Achieving carbon-neutrality is increasing the demand of renewable electricity which is raising the competition for land and associated acquisition costs. Installation of floating photovoltaic (FPV) on existing hydropower reservoirs offers one solution to limited land availability while providing solar electricity, leveraging water bodies, and reducing water evaporation losses. This work assesses the potential electricity output of FPVs at regional and national levels on 337 hydropower reservoirs in the EU27 considering four scenarios and two types of floaters. Evaporation, water losses and water savings due to FPVs installation are also estimated using climatic parameters for the year 2018. The reservoirs' total water losses are estimated at 9380 mcm. The installation of FPVs of equal installed capacity as the hydropower plants, has the potential to generate 42.31 TWh covering 2.3% of the total reservoir area. In this case, up to 557 mcm could be saved by installing FPV. The FPVs' multiple benefits and the potential offered by existing hydropower reservoirs are compatible with the EU's goals for net zero emissions and more autonomy from imported fossil fuels and energy transformation.

Prioritization of Renewable Energy for Sustainable Electricity Generation and an Assessment of Floating Photovoltaic Potential in Lao PDR

Lao PDR faces seasonal power supply problems due to its heavy reliance on hydropower. Thus, the aim of this paper was to prioritize renewable energy (RE) resources for sustainable electricity generation in Lao PDR using the analytic hierarchy process (AHP) method, and to further estimate the energy available for the prioritized RE to enhance the seasonal power supply. Four RE alternatives were assessed considering technological, economic, environmental, and social criteria with twelve overall sub-criteria. The results indicated that hydropower was the most highly prioritized alternative, followed by solar. The resulting weights of the RE prioritization were in agreement with the Lao energy policy and plan. In order to address the seasonal power supply problem, setting-up floating photovoltaic (FPV) units in the existing hydropower reservoirs was proposed. The FPV potential was estimated, and the results revealed that the predicted power demand by 2030, as calculated in the latest Lao national power development strategy, could be fully covered by integrating the FPV output from 10% coverage of the water surface in four existing hydropower reservoirs with the existing power supply in 2020. The proposed FPV technology would provide a solution to enhance the seasonal power supply and reduce the power import.

Evaluation of thermal boundary conditions in floating photovoltaic systems

AbstractReconciling the use of space and the production of low‐carbon electricity is a key challenge in the face of changing human needs. In this context, floating photovoltaics (FPV) is proving to be a key application to colocate energy production with several activities (hydroelectricity and aquaculture). A major benefit of FPV technologies is the reduced module temperature. However, the causes of this thermal observation are still unknown. The density of the distribution of the floaters and the thermal behavior of the waterbody are two postulated roots that show positive correlations with regard to the module temperature. Therefore, there is interest in identifying precise thermal features in the application because the yield surplus promised in FPV technology is based on this cooling effect. This research aims to understand the heat mechanisms that arise in this application in comparison with ground‐mounted photovoltaics (PV). A special framework based on 1‐D thermal modeling and statistical classification of the results by dimensionless related features is proposed. This strategy offers a possibility to differentiate the influence of the thermal modes separately over the module temperature. First, a gain of 20% to 50% in the convective transfers is demonstrated for FPV compared with ground‐mounted applications. Data exploitation associates these gains with the forced convective effects of the wind blowing on the front of the modules. Gains in free convective transfers are associated to the airflow around the module rear face, reducing the phenomenon of thermal buffering. The framework also demonstrates that the emissivity‐based correlations for the radiative boundaries are in good agreement with the radiative phenomena involved in FPV. When convection preferentially cools down the module, the participating media nearby acts as a heat source, warming the installation. Thus, understanding these mechanisms in the FPV application would provide opportunities for improved temperature management through floats or array‐scale optimizations.

순환신경망을 이용한 수상 태양광 발전량 예측

Renewable energy has advantages in environmental aspects such as greenhouse gas reduction and fine dust reduction, but the stability of the power system is lowered due to the variability & uncertainty of renewable energy sources. Therefore, it is important to predict the amount of generation of renewable energy, which can contribute to system stabilization. In order to predict the power generation of floating photovoltaic(FPV), the generation amount of 500㎾ FPV and meteorological data were used to predict the power generation through the Recurrent Neural Network(RNN). To perform appropriate prediction, identifying the correlation between variables, removing multicollinearity, handling missing values properly are performed and the amount of power generation is predicted through appropriate RNN. In addition, it is analyzed how the influence of wind affects the amount of power generation of FPV

Thermal regulation of partially floating photovoltaics for enhanced electricity production: A modeling and experimental analysis

The thermal regulation of the floating photovoltaic (FPV) system increases its electrical potential. In this study, a partially floating photovoltaic (PFPV) system was examined by submerging a portion of the FPV module to realize excess heat release. An appropriate MATLAB/Simulink model was constructed for a comparative study of three FPV configurations to reveal the electrical benefits of the PFPV system. The proposed model was validated via experimental work under actual outdoor conditions, which revealed well-matched results. According to the modeling findings, submerging half of the PV module in the water body realized a temperature of 29.71 °C, a temperature drop of 28.24 % compared with that of the typical FPV system (41.40 °C). The electrical power generated increased by 5.57 % when 25 % of the active area of the PFPV system was submerged. Furthermore, the findings revealed that the electrical efficiency of the PFPV module reached 15.72 % when 25 % of the PFPV system was submerged, achieving an efficiency improvement of 3.95 % compared with the conventional FPV system. The superiority of the electrical performance of the PFPV system with a submerged area of 25 % in the modeling and its experimental validation ensure the proposed concept validity.

Effect of floating photovoltaic system on water temperature of deep reservoir and assessment of its potential benefits, a case on Xiangjiaba Reservoir with hydropower station

As green energy, the floating photovoltaic (FPV) system has many advantages. Taking Xiangjiaba reservoir as an example, a Ce-qual-W2 model was established to evaluate the potential impact of the FPV system on water temperature and its potential benefits. The result showed that: (1) FPV system could reduce the water temperature, water age, and relative water column stability of the reservoir; (2) the influence range of FPV on water temperature will not exceed 20% of reservoir length outside the coverage area in the flow direction. (3) FPV system would delay the reaching time of critical temperature threshold and accumulated temperature threshold for Coreius heterodon spawning, shorten the spawning period. The delay time of AT and CT under 100% coverage are 20.3 and 7 days respectively compared with no FPV condition; (4) FPV system can play a great role in power generation and emission reduction. Under 100% coverage, the power generation can reach 17.2 billion kW·h, reduce 14.4 million tons of carbon emissions and save 35.12 million m3 of water. This study can provide a reference for the impact assessment of the FPV project on the water environment and the formulation of the FPV coverage scheme.

Thermal and electrical performance of solar floating PV system compared to on-ground PV system-an experimental investigation

Floating Photovoltaic (FPV) is a relatively new concept for producing clean green energy. This study presents the results of an experimental investigation of a small-scale FPV system. The goal is to evaluate and compare the thermal and electrical performances of mono and polycrystalline photovoltaic modules used in FPV with those of On Ground PV (OPV) systems with a similar nominal capacity. To accomplish this, a test bench consisting of an FPV and an OPV system has been established. The results show that when the water body is partially covered with a Floating PV system, water evaporation is reduced by 17%. And it is reduced by around 28% when fully covered. It was also found that water bodies provide an adequate cooling effect. Lowering the front temperature of Floating PV modules by 2–4% and the back temperature by 5–11% compared to similar On-ground PV modules. Thermal imaging revealed that at 0 degrees of tilt, the front temperatures of the modules are uniform. Still, as the tilt increases, a temperature gradient is observed between the bottom and middle parts of the modules. In addition, an experimental test was performed to compare the power generation of Floating PV at varying tilt angles. The test results show that the Floating PV system produces the most energy when installed at the annual optimal tilt angle. As a result, for FPV, adjusting the Photovoltaic panels to their optimized tilt angle is also recommended. While Floating PV system produces 20–28% more energy than the on-ground PV system at 0°as compared to the optimal tilt angle.

Design and Implementation of a Floating PV Model to Analyse the Power Generation

The floating photovoltaic (FPV) system is a revolutionary power production technology that has gotten a lot of interest because of its many benefits. Aside from generating electricity, the technology can also prevent the evaporation of water. The electrical and mechanical structures of FPV power stations must be studied to develop them. Much research on FPV technologies has already been undertaken, and these systems have been evaluated from many perspectives. Many problems, including environmental degradation and electricity generation, fertile soils, and water management, are currently limiting societal growth. Floating photovoltaic (PV) devices save a great of land and water resources and have a greater energy conversion efficiency than standard ground power systems. A performance investigation of photovoltaic (PV) installations set on a moving platform is carried out. The paper presents and discusses various design alternatives for boosting the profitability and efficiency of floating photovoltaic (FPV) systems. Especially, FPV systems that take advantage of increasing capabilities like monitoring, conditioning, and attention were included. Although researchers have agreed on the benefits of floating systems, there has been little in-depth research on the parameters of floating photovoltaic systems. The results of this research tests were performed, and these reveal that the beneficial monitoring and conditioning impacts result in a significant gain in performance. The effects of using flat reflections on improvements are also investigated. As a result, this research examines the evolution of photovoltaic systems, then investigates the power generation capacity of floating photovoltaic systems, and then examines the benefits and possibilities of floating PV systems in depth. The concept of developing an integrated air storage system using a floating building on waters is discussed.

The performance and amphibious operation potential of a new floating photovoltaic technology

Floating photovoltaics (FPV) is a rapidly emerging technology that provides an alternative to ground-mounted PV (GPV), particularly where land is scarce or expensive. Despite an impressive technological development and growth in installed capacity in recent years, studies on the performance and reliability of FPV are scarce. This work provides insight with respect to the performance, reliability, and operational characteristics of a new FPV technology with the aim to identify innovation opportunities, reduce risks, develop improved solutions, and improve bankability of FPV. We have analysed production and weather data from one year of operation for an open FPV system with a small water footprint located on a water body in Kilinochchi, Sri Lanka. The technology is developed by the company Current Solar. Using established filtering routines and algorithms from pvlib, the yield and performance ratio is calculated and compared to a GPV system installed on the shore of the lake. We find that the technology gives a stable overall performance over the one-year period, and that the period of amphibious operation did not impact the continued performance of the system. Calculations of the U-value of the system, based on the production and weather data, gives a median U-value of 33 W/m2K, slightly higher than the default PVsyst value of 29 W/m2K for freestanding GPV systems. The calculated U-values are used in an energy yield analysis in PVsyst to estimate the energy production of the FPV technology and benchmark it against measured data.

Floating photovoltaic plants as an electricity supply option in the Tocantins-Araguaia basin

Brazil has high solar potential. The yearly sum of solar irradiation is approximately 1924.07 kWh/m2, therefore, harnessing this potential is promising. The country is dependent on hydroelectric plants, however, increasingly frequent droughts have severely affected hydrogeneration. The installation of floating photovoltaic (FPV) systems in existing hydropower reservoirs, would provide additional electricity to help compensate hydropower production during dry periods and reduce evaporation losses while helping to sustainably meet Brazil's electricity demand. This study provide an analysis of FPV potential in Brazil's region, named the Tocantins-Araguaia Basin, by using water surface data from 30 hydropower reservoirs. In addition to the new electricity production, evaporation savings and its extra potential hydroelectricity were also estimated. A survey of the reduction in CO2 emissions was conducted, given that the complementary electricity to hydroelectric plants would be through solar generation, thus avoiding the activation of thermoelectric plants. The main results indicate the high FPV potential, corresponding to an electricity production that varies from 25.04 to 2555.04 TWh/year, and a range of 19.86–2024.30 million tCO2/year of avoided emissions. Regarding the potential arising from the evaporation water savings, the values vary between 16.17 and 892.95 GWh/year.

Design of Double‐Network Click‐Gels for Self‐Contained Underwater Adhesion and Energy‐Wise Applications in Floating Photovoltaics

AbstractFacile fabrication of rapid, firm, and reversible underwater adhesion used on different adherets is challenging but is of primary importance for many industrial and biomedical applications. Herein, tough, stretchy, moldable, and semitransparent gels are developed for self‐contained underwater adhesives. The selected structural components, well‐defined double‐network (DN) structures, and one‐pot synthesis realize synergistic adhesion and cohesion engineering, which deliver instant, solid, reversible, and long‐term adhesives with a high underwater adhesion strength of over 0.84 MPa. The underwater adhesion strength is among the best‐performing tape‐type underwater adhesives. In order to develop new energy‐related applications for underwater adhesion, the first example of combining underwater adhesion with solar power applications is demonstrated. Taking the benefits of the direct‐contact design at the air/water interface, the click‐gel‐mounted floating photovoltaic (FPV) system significantly increases the power conversion efficiency by 20% due to the enhanced active cooling effects, surpassing several conventional photovoltaic technologies on both land and water. The click‐gel also rapidly responds to several oscillatory motions on the FPV platform. This study shines a light on the facile fabrication of DN click‐gels for underwater adhesives and provides their future perspectives in energy‐wise, low‐maintenance, and stimuli‐responsive applications.

Techno–economic–environmental comparison of floating photovoltaic plant with conventional solar photovoltaic plant in northern Iran

Abstract Photovoltaic (PV) systems can be used to generate electricity due to the potential for solar energy in Iran. Applying floating photovoltaic (FPV) systems is a new approach to utilizing PV systems in water. Most of Iran’s energy consumption is supplied from fossil fuels, especially oil and gas. In recent years, Iran has faced environmental problems and air pollution. Electricity generation using fossil fuels has led to increased environmental pollution. Accordingly, PV systems can be used to generate electricity due to the potential for solar energy in Iran. The interest in predicting the energy production of PV power plants has increased in recent years. In this regard, the techno–economic–environmental study of constructing PV power plants is a basic process to encourage people to use solar energy. A techno–economic–environmental feasibility study has been performed to construct a 5-kW FPV and ground PV (GPV) power plant in a northern city of Iran. Also, the FPV system is compared with the ground PV system using MATLAB® Simulink and RETScreen® software. In this study, the effects of wind and water temperature have been considered. Also, a sensitivity analysis was performed due to the uncertainty in climatic conditions and the amount of PV energy generation. The simulation results show that due to the cooling effect for panels in the FPV system, the production capacity and panels’ efficiency are respectively 19.47% and 27.98% higher than the those of the GPV system. In addition, the FPV system was found to have a 16.96% increase in the annual performance ratio. Overall, using the FPV system reduces the equity payback to 6.3 years (a 22.2% reduction compared to the GPV power plant).

Advancing simulation tools specific to floating solar photovoltaic systems – Comparative analysis of field-measured and simulated energy performance

The land-use intensity and performance-related issues in the solar energy sector have led to the development of floating photovoltaic (FPV) systems that allow solar photovoltaic (PV) installation on water bodies. The FPV systems present two-fold benefits in terms of mitigation of land-use conflicts and improved energy performances. While such experimental studies exist in the literature, the critical apprehensions related to performance feasibility assessments during the project planning are still unclear due to the lack of simulation tools specific to the FPV. Also, given the high uncertainty in solar PV performance, which varies from location to location, the existing experimental studies may not help in benchmarking and revealing the need for simulations specific to FPV. In reality, most installers/researchers are still using simulation tools that apply to conventional PV installations, and that do not account for the PV-water interaction and cooling effect caused. Until now, without realising this, the service providers are providing inaccurate performance feasibility reports to clients who wish to deploy FPV. Hence, this study investigates whether the existing simulation tools can be applied for FPV planning by taking a 2 MWp FPV power plant installed on the urban water reservoir in Southern India as a case study. First, the field measured data of the 2 MWp FPV plant is monitored. Second, the same is simulated in three different software tools: PVsyst, System Advisory Model (SAM) by National Renewable Energy Laboratory (NREL), and Helioscope. Third, error metrics-based methodology is applied to understand the deviation in energy output, capacity utilization factor (CUF), and performance ratio (PR). The results advocate that deviation in energy from the measured to simulated varies significantly from 18.43 to 38.55%, suggesting that none of the considered simulation tools suitable for FPV project planning. Similarly, other performance indicators are analysed, followed by a discussion and data-driven recommendations leading to the conceptual simulation tool development for FPV.