Human social activities and lifestyles, as well as aquatic habitats, are influenced by fossil fuels. Carbon and hydrogen are the primary components of fossil fuels, but they also contain other substances e.g., lead, sulfur, and alcohol). Fossil fuel combustion results in the production of a variety of gases (COx, SOx, NOx, CH) ash and soot, tar droplets, and other organic compounds into the atmosphere, all of which contribute to air pollution. The health of people, animals, crops, and buildings is harmed by air pollution (Barbir et al., 1990). According to a statistical review of World Energy (2020), almost 84.3% of global energy comes from fossil fuels containing 33.1% of energy from oil resources, which always remained the main driver behind increasing oil prices in the international market and renewable has a share of only 11.4% of overall energy consumption (Statistical Review, 2020).

From the perspective of Asian countries, this energy mix situation is even more alarming as compared to other developed nations. For some countries, the domestic sector has the highest energy consumption share of 48%, while the industrial sector contributes 27% of the overall energy consumption (Raza et al., 2022). For some countries, the energy supply is mostly dependent on fossil fuels, with more than 63% thermal energy. Renewable energy (RE) like solar and wind often accounts for very little up to 3% of total electricity generation (Raza et al., 2022).

Renewable energy sources are the best option for addressing these challenges because of their long-term sustainability and environmentally friendly options (Goswami et al., 2019). Because of the threat posed by GHG emissions from fossil fuels and associated power generation, the usage of environmentally friendly renewable energy, notably SPV has gained enormous popularity as its demand has steadily increased by 20%–25% per year across the globe over the first 2 decades of the twenty-first century. The rate of expansion of RE capacity has been fast-growing, yearly renewable capacity additions reached 45% to about 280 GW in 2020, the biggest annual increase since 1999. Its appeal is based mostly on semiconductor technology, environmental benefits, policy-intensive nature, and ease of installation. Because they never run out of resources, photovoltaic (PV) and wind energy are the most widely adopted renewable energy sources across the globe. Most Asian countries have a good potential for solar or wind generation or hybrid. Most of the Asian countries existing energy mix is heavily reliant on fossil fuels (Ministry of Energy Petroleum Division, 2018).

The effective use of renewable energy potential is necessary to assure energy security and reduce climate change challenges. Further observations show that ground-mounted PV power plants in modern towns take up a lot of territory. As a result of this factor, land prices have risen, increasing the Levelized power tariff. The earth’s total surface area is made up of 71% of water and 29% land. Land acquisition is another issue to address as the population grows, so the best solution is to put the water’s idle surface to good use. Where, at the one hand, solar energy is gaining popularity due to its limitless energy supply. At the same time, on the other hand, the climatic conditions, design parameters, and operation parameters affect the performance of PV, due to which a 0.5% reduction in PV efficiency is observed by a 1°C increase in temperature. PV efficiency gets decreased, as the module temperature increases due to a higher thermal effect of solar irradiance. Two major issues associated with land-based PV (LPV) i.e., land acquisition and high temperature have been solved by an emerging PV system concept called FPV. A comparison of LPV and FPV is given in Table 1.

This concept works best in densely populated areas with uneven terrain. For hot and arid regions, FPV has a lot of potential since the operating temperature can be controlled and the PV performance can be optimized. FPV systems offer new ways to expand solar power generation capacity due to their high efficiency as compared to LPV. They can be integrated with hydroelectric power plants and have a considerable impact on supplying electric load in various spans of the year, particularly during the hot and dry seasons. A standalone system needs a large power storage infrastructure, which almost doubles the system’s overall capital cost, and challenges the economic feasibility of the systems (Temiz and Dincer, 2021). Moreover, as the number of components increases, it suffers a significant power dissipation loss which poses a substantial challenge to system performance. As a result, grid-connected configurations are widely adopted for most practical scenarios.

In comparison to LPV systems, FPV provides technological, economic, social, and environmental advantages. Furthermore, due to fluctuating fuel prices on the worldwide market, electricity prices are always changing. Hydropower accounts for 26% of total output, and the dam’s idle surfaces may be utilized to generate energy by dedicating water surfaces to FPV installations. An integrated infrastructure of floating systems and PV plants is referred to as an FPV plant. A crystalline and thin-film FPV offers financial benefits of more than $129 cents/L over diesel-fueled energy production sources (Trapani and Millar, 2016). The efficiency of the LPV system is around 15%, which may be enhanced further by using FPV to take advantage of the cooling effects of water. FPVs are also favored over LPVs because they have a recyclable platform. Additionally, they are recommended for generating energy in remote locations and places with land accessibility and water conservation issues, such as salt mines and oil refineries that are far from grid stations.

The development of FPV systems is in its early stages, emphasizing the need for comprehensive long-term performance and feasibility studies. Precise parameter estimation is crucial for gauging actual performance, carbon savings, and facilitating the deployment of FPV systems. Accurate modeling not only supports researchers, scientists, and engineers in making informed decisions but also contributes to the establishment of a sustainable ecosystem aligned with low-carbon power generation methods within the framework of Industry 4.0 (Goswami and Sadhu, 2022). Notably, FPV systems, operating on water with higher relative humidity and lower temperatures compared to LPV systems, exhibit superior energy output despite the observed impact on the performance ratio (PR). This underscores the potential of FPV systems to offer efficient and sustainable solutions in the evolving landscape of renewable energy (Goswami, 2023). FPVs are preferred over LPVs for several reasons, including FPVs avoid high dust accumulation because they are installed on the surface of the water, FPVs reduce evaporation in water reservoirs, decrease GHG emissions, Save high land purchase costs, utilize idle water surfaces, address the problem of increased electricity transportation costs, conquer high-temperature impacts on SPVs, reduce algae growth, satisfy energy demand, and overcome long and tedious installation times.

Several states in the United States have set a goal of producing 100% renewable energy-based green power by 2040, incorporating both centralized and decentralized generation. By 2040, several European and Asian countries have set a target of producing more than half of their total electricity from renewable sources (Uddin et al., 2022).

IRENA has identified FPV as a rising niche and an emerging technology. According to NREL, FPVs have a 7.6 TW potential on hydropower reservoirs. In almost 40 countries, FPVs have been built on reservoirs, freshwater lakes, and dams. Since 2007, different FPV plants ranging in size from a few kW to a few megawatts have been developed and are now functional in many countries (Trapani and Redõn Santafé, 2015). The first 20 kW FPV system was installed in Japan in 2007, and Ciel & Terre was the first FPV installation French company has built several projects on both artificial and natural water bodies. According to a market perspective, the global market for FPV is growing rapidly, and it is predicted to reach $842 million by the end of 2023. According to the IEA, adding FPVs to the water bodies of hydropower stations may yield a potential power of roughly 10,600 TWh per year, whereas total world energy consumption in 2018 was 22,300 TWh.

Internal cell temperature has a significant impact on solar PV efficiency. The cooling effect of the water surface reduces the internal temperature which boosts the system’s energy efficiency by 5%. Among renewable technologies, FPV technology is becoming more attractive for both research and commercial operations. It is expected to reach 4.13 GW of installed capacity by 2024, with a compound annual growth rate of 30%. Although installing a floating structure, extra insulation, and equipment increases capital and operational costs by 25%, lower land prices may compensate for the higher expenditures (Temiz and Dincer, 2021). The primary issue with FPV is the initial investment, which is decreasing with time and will soon be competitive with LPV. The solar industry in Asia is booming, thanks to the fact that 78% of Asia’s water bodies are appropriate for FPV installation. FPV is a cutting-edge technology that can solve the current energy deficit while also providing economic and environmental benefits by lowering C O 2 emissions.

A test case in India is taken on the Mettur dam in Tamil Nadu to analyze the performance of FPVs. A land-scaped flat-mounted system was found to have a high-performance ratio (PR). A 1 MW FPV system having a component configuration of four 250 kW inverters, four blocks, and twenty strings was proposed by Indonesia in 2019. Three reservoirs were chosen for simulation and modeling reasons. Sungrow, a Chinese business, built a 600 kW FPV plant in Hanoi, Vietnam. Table 2 shows a potential summary of FPV from 2007 to 2017. Recently Portugal launched an auction of 26 MW which is allocated to seven different dams, having diverse capacities, summarized in Table 3.

A total of ten of the largest FPV farms are summarized in Table 4. There are various FPV solution providers for offshore, near-shore, and interior freshwater applications all around the world. FPV solutions for inland freshwater are provided by companies such as Ciel & Terre International, Kyoraku, LG CNS, LSIS, Scotra, SMCC, Sungrow, and Xiamen Mibet New Energy while floating technology solutions for offshore uses are provided by Ocean Sun and Swimsol.

As the world’s population grows, land use competition for buildings, industry, power production, transportation, and ecosystem products and services intensify. FPV systems have shown promise as a technical solution for land acquisition, and several studies have been conducted, with these systems being examined from a variety of angles. A rigorous techno-economic and sustainability assessment of these solar technologies reveals a plethora of benefits, including cost-effective and environmentally friendly solutions. Due to its high initial investment and lack of appropriate water bodies, FPV technology currently faces several technical and practical challenges. Various studies have been performed to carry out these challenges across different regions with different sites’ specific natures. Pietro et al. (Campana et al., 2019) have proposed an approach to analyzing numerous scenarios for optimal integration of hybrid renewable energy systems into a typical shrimp farm by taking the case of Thailand with the aims of renewable energy exploitation and decarbonization of the shrimp farming sector. FPV plants and FPV tracking systems are being examined as solar energy solutions to supply the shrimp farm’s power requirements. The authors investigated the integration impacts with the different optimal configurations of hybrid energy sources. Results summarized that the incorporation of FPV is a crucial approach for minimizing shrimp farming’s ecological consequences.

In India, FPVs have a lot of potential, and their efficiency is thought to be higher than that of LPVs. FPVs can manage and minimize algae growth and water evaporation by 70% and require less maintenance. FPV is made up of three basic parts: a mooring system, a pontoon, and floats. By altering the tilt angle of the PV panels, the problem of water shading may be solved.

During rainy seasons, the mooring system should be strong enough to withstand the effects of flooding (Akole and Jadhav, 2018). Temperature and dust are two important effecting variables in SPV that can be addressed with the use of FPVs. The FPV system is considered an ideal solution for land-constrained sites, high population density, numerous water resources, and high evaporation rates. FPVs are cost-effective solutions due to lower cleaning costs and no need for land (Zahedi et al., 2021). Contraction, tracking, and cooling techniques for FPVs can help in increasing the efficiency of the overall PV system. Flat reflectors and positive trackers enhanced power generation considerably. A different indicator like the thermal coefficient plays a major role in predicting the efficiency of system. A negative thermal coefficient means that the efficiency of the commercial PV system is inversely proportional to cell temperature. For silicon crystalline PV technologies, it ranges from 0.4% to 0.45%/^oC whereas for a-Si it is 0.2%/^oC (Cazzaniga et al., 2018).

An FPV power plant might help the San Francisco River Integration Project (SFIP), which aims to supply water to 12 million people in the Brazilian semiarid. The SFIP needs a substantial quantity of energy in an area where power costs have climbed, and water usage has increased over the previous decade. The results established the techno-economic feasibility of this technology linked to the SFIP by simulating an FPV power plant using the System Advisor Model (SAM) employing approaches and parameters from existing FPV projects. The FPV’s environmental implications and importance in the Brazilian Northeast’s water-energy nexus are also examined by Luana Carolina Alves da Costa et al., (da Costa and da Silva, 2021). The FPV might reduce SFIP running costs, reduce environmental impacts, and increase water and energy management efficiency. Such elements are significant when looking at the water-energy interconnection in a location where there is strong competition for water and extended periods of drought.

Southern European countries have ideal climate conditions for boosting solar energy adoption. J. Baptista et al. (Baptista et al., 2021), looked at the possibility and grid integration for FPV systems in Portugal. The Gouves dam, which is part of the Tâmega hydropower complex under development in northern Portugal, was used to test the sizing and performance of a 1 MW FPV power plant. A techno-economic feasibility analysis was also carried out, taking into account the current investment costs and energy tariffs in the liberalized Iberian market. This in-depth analysis uncovered crucial information regarding the present state of the art, the types of technologies that are accessible, their costs, and the payback period (PBP) for similar projects. In 2020 J. Haas (Haas et al., 2020) took to Rapel reservoir in central Chile to examine the impact of FPVs on water quality as well as on hydropower production. FPV reveals several advantages including water quality improvement by eliminating algae blooms and the area covered with FPVs has a direct impact on cost and ecological health. If 40%–60% area will cover it can eliminate 100% of algae without severe financial hydropower loss. For more than 60% of the area covered, ecological heath will affect major economic hydropower loss because of no sunlight in the reservoir. Evaporation from open water reservoirs, such as dams, results in a significant loss of water resources. By merging FPVs with HEPP, water is conserved as well as power is generated for electrification purposes. For nearly 2 decades, satellite photographs of Turkey’s Demirköprü dam were used to locate the best location for FPV installation, where high power generation was recorded with minimal evaporation (Ates et al., 2020). China has a rich potential for FPV installation having almost 2,865 lakes with a surface area of 78,000 sq. km. The efficiency of FPVs over standard terrestrial PVs improves when the operating temperature drops due to the cooling effect (Liu et al., 2017). R. Cazzaniga et al. (Cazzaniga et al., 2018) investigated the performance of FPV plants and proposed various design options for increasing efficiency and cost-effectiveness. FPV systems, in particular, make use of added characteristics like cooling, tracking, and concentration. A floating structure on the water was used to demonstrate the possibility of constructing an integrated air storage system.

According to the findings of (Goswami et al., 2019), The production capacity of a 10 MW FPV plant is 10.2% higher than an LPV system. The FPV plant saves $352,125 in land expenses and $47,600 in water cess. Furthermore, the FPV plant saves tons of coal and 340801.74 tons of C O 2 . It helps to close down the energy demand-supply gap while also cutting electricity costs and protecting natural resources. A case study of a 1 MW FPV plant at Ambazari Lake in Nagpur, Maharashtra, India is presented by Swati S. Gurfude et al. (Gurfude et al., 2020). The generating efficiency of an FPV plant will be 2.5%–3% greater than that of a standard ground-mounted PV plant, and evaporation would save 191 million liters of water each year. The FPV plant will be able to close the gap between electrical energy demand and supply.

Integrating FPVs with HEPP by installing them at dam reservoirs to make use of the optimum energy combination is also a brilliant way to save money associated with transmission and distribution infrastructure. In Bangladesh, the technical feasibility and financial viability of a 50 MW plant integrated with a hydroelectric dam were investigated. The plant may reduce C O 2 emissions by 52.8 million tons by using an ecologically sustainable strategy. In comparison to terrestrial LPV plants, FPVs have several advantages, including fewer obstacles to block sunlight, reduced water evaporation, irrigation, and domestic sustainability, higher energy efficiency due to the cooling effect of water, and the ability to limit algae growth by restricting sunlight penetration (Miah et al., 2021).

According to literature surveys, relatively few studies on the techno-economic, environmental, and social (TEES) assessment of grid-connected FPV systems for various sectors have been published. Most of the studies are related to techno-economic analysis of standalone FPV system. For example, with the goal of evaluating the feasibility of implementing a FPV system on an urban lake site, the authors in reference (Hafeez et al., 2022) conducted a techno-economic assessment. This assessment aimed to estimate the potential deployment of the FPV system, assess its scope, and compare it with a ground-based photovoltaic system with similar specifications. The study focused on an urban lake within institutional premises. In reference (Micheli et al., 2022), the authors evaluated the potential energy yield and cost-effectiveness of FPV systems over appropriate water bodies in Europe. The comparison was made against land-based photovoltaic systems with optimal tilt angles. In reference (Kowsar et al., 2023), researchers conducted a comprehensive examination of the techno-economic and environmental aspects of a 50 MW FPV power plant situated in a marsh area within an extremely densely populated country. Utilizing PVsyst simulation tools, the study revealed that the levelized cost of energy (LCOE) for the 50 MW FSPV plant is US$ 0.051/kWh, significantly lower than the US$ 0.087/kWh observed for fossil fuel-based power plants in the studied nation. Additionally, the proposed FSPV system contributes to reductions in CO₂ emissions, water evaporation, and supports biodiversity conservation in marshlands. Likewise, employing a GIS-MCDA model, an evaporation model, and incorporating a cost-benefit analysis, the study outlined in (Bai et al., 2024) assessed the prospective growth of FPV systems in China. The research delves into the energy-land-water co-benefits associated with FPV. Additionally, the analysis extends to unveiling the existing land limitations for the deployment of solar photovoltaics in China, with an evaluation of the potential for traditional terrestrial solar photovoltaic systems. To the best of the authors’ knowledge, no study in the literature reported an integrated analysis of techno-economic, environmental, and social (TEES) feasibility along with performance evaluation of mega-scale FPV systems, especially from the metrological and geographical point of view of south Asian country. It is worth mentioning here that FPV installation and performance work differently compared to LPV. Various parameters like U-value and Albedo differ in FPV as compared to LPV. Most of the previous studies performed an analysis based on the same or default U-value and Albedo for FPV as these are kept in LPV. However, in actual conditions, for correct analysis and performance evaluation of FPV, the U-value and Albedo should be customized differently as compared to LPV. For that reason, in this study, these parameters are customized in PVsyst during simulation to reach the true cost of energy and other technical and performance parameters. Moreover, no study has been reported in the literature concerning forest absorbing carbon emissions analysis along with environmental analysis. As well as previous studies have focused on limited decision parameters, mostly NPV and LCOE to reach the optimal decision regarding the techno-economic feasibility of FPV systems. In contrast, this study has focused on various techno-economic, performance, and environmental decision parameters at the same time. A comparative analysis of previously reported studies and the contribution of the proposed study is summarized in Table 5. Likewise, similar studies have conducted in (Ma et al., 2023) where concentrated solar power, offers reliability and dispatch by complementing extensive thermal energy storage. The concerned stability regions can-be tackled accurately for grid-connected systems, by employing a nonlinear multi-parameter analysis method based on tracking limit cycle amplitudes (Yao et al., 2024) and can mitigate consumption conflicts with the potential to meet total electricity demand (Yang et al., 2024).

The current study will examine the technical, economic, and socio-environmental benefits of a 2.5 MW grid-connected FPV system in five climate zones and propose a strategy for installing an FPV system in the most favorable climate zone to tap new technology-based renewable potential and to improve the country’s current energy mix. To the best of the authors’ knowledge, no study in the literature has provided a thorough feasibility analysis of significant water bodies. The majority of the research examined just one or two climatic scenarios to assess the viability of floating infrastructure. This study encompasses a variety of meteorological zones with an emphasis on the country’s current climate conditions. Additionally, the majority of earlier studies did not use on-ground inputs, whereas proposed investigations concentrate on on-ground inputs to determine whether the proposed architecture is feasible. From an environmental analysis point of view, the literature has substantially focused on only emitted carbon emissions. No study regarding FPV focused on providing an alternate solution for the mitigation or absorption of these carbon emissions. The current aims are to conduct forests absorbing carbon emissions analysis along with carbon emission analysis to carry a policy solution to absorb the same carbon emissions. In a nutshell, the major contribution with respect to the reviewed literature is shown in Table 5.

This paper is organized as follows: Section 1 carried the introduction of current energy scenarios across the globe and more specifically in Asian countries. Section 2 carried the history behind applications of FPV and some major associated projects across the globe are summarized. In Section 3, a literature work is summarized, and research gaps are identified. The methodology is summarized in Section 4. In Section 5, results and discussion are carried out briefly. In Section 6, tracking FPV is discussed and in Section 7, the limitations of the FPV plant are discussed. Finally, the policy recommendations are carried out in Section 8 and the paper is concluded in Section 9.

FPV plants are well-established technologies. FPV can be installed on various sites mainly categorized as man-made or artificial water bodies, industrial and agricultural water bodies, and offshore water bodies (Where Sun Meets Water, 2019). In this research, man-made or artificial water bodies are considered like dams and barrages to perform multidimensional analysis for finding out the most practical site for FPV installation. Furthermore, these sites are divided into subcategories explained in Figure 1A.

To examine the most essential impact characteristics, five representative sites including Zone A dam, Zone B dam, Zone C dam, Zone D dam, and Zone E dam were selected to represent the five climatic zones for the techno-economic-environmental and social analysis of a 2.5 MW FPV. Table 6 offers coordinate details for selected sites, and cities, whereas Figure 1B depicts the geographical placements of the five climate zones. Solar PV systems with a 1 MW capacity require around 20,000 square meters of land to install (Where Sun Meets Water, 2019). Approximately 50,000 square meters of land would be saved by installing a 2.5 MW FPV system. In this study, the discount rate and inflation rate are taken as 9.75% and 8.5%, respectively.

In this section, a comparative technical analysis of 2.5 MW solar plants in five climatic zones is offered. Furthermore, a techno-environmental analysis for each case in the specific site is described in detail. In the first fold, based on PR and specific production (SP) technical analysis of a 2.5 MW FPV plant for each under-study zone is carried out (Song and Choi, 2016; Pasalic et al., 2018). In the second fold, an economic analysis is carried out based on NPV, LCOE, PBP, etc. Similarly, in the third and fourth fold, environmental and social analyses are carried out based on balanced GHG emissions and the SDGs set by United Nations member states, respectively (El Hammoumi et al., 2021).

In this study, a techno-economic and sustainability assessment analysis of a grid-connected FPV system is carried out for five different climate zones. Techno-economic and environmental analyses are carried out based on different decision indicators like PR, CUF, LCOE, NPV, PBP, ROI, and GHG emissions. Zone B dam appears to be the least feasible site with LCOE of $0.057/kWh and NPV of million $1.0256. On the other hand, Zone B dam is the most feasible location with LCOE of $0.047/kWh and NPV of million $1.7705. While socio analysis is carried out based on SDGs especially (SDGs 2-8 & 13-15). The detailed multi-dimensional analysis showed that all selected sites (dams and barrage) in respective climate regions are feasible for the installation of a 2.5 MW FPV system. Zone C dam among all sites showed a better performance in terms of the proposed analysis. On the other hand, Zone B Dam showed the least feasible performance amongst all selected sites under the same evaluation criteria. The most practicable location is Zone C dam, which has a PR of 85.6% and a PBP of 6 years. The least feasible site is Zone B dam, which has a PR of 84.3% and a PBP of 8.3 years.

In addition, equivalent forest-absorbing carbon analysis has been carried out in RETScreen Expert software for each under-study climate zone. Results showed 43125.7 tons and 34283.8 tons of carbon emissions which are equivalent to 3924.439 and 3119.826 ha of forest absorbing carbon for Zone C dam and Zone B Dam, respectively. The results of the proposed study are later validated with real-time data of the on-ground 2.5 MW PV project in Fateh Jang, which shows a significant edge in techno-economic and performance parameters for FPV as compared to the LPV system. The 2.5 MW FPV proposed system at Zone C dam has an 85.6% PR compared to the 2.5 MW LPV existing system at Fateh Jang has a 79.2% PR, indicating that FPV performs better than LPV. The proposed study can be a decision pathway toward policy optimization for the installation of FPV technology. The current study is performed on manmade and artificial water bodies. In the future, the proposed study can be enhanced to other sites like industrial, agricultural, and offshore water bodies. In addition, a similar study can be performed on small-scale ponds and lacks local rural or off-grid communities. The proposed study can lead to policy recommendations for stakeholders toward investment in FPV sector.