Floating solar photovoltaics (FSPV) is an emerging installation approach in the solar photovoltaics (PV) power sector that maximizes power output when compared to its counterpart ground-mounted photovoltaics (GMPV) (Ram et al., 2018). FSPVs are generally installed on water bodies such as oceans, rivers, lakes, reservoirs, wastewater treatment, fish ponds, and others (Kumar et al., 2020a). The primary push for FSPV installation has become a reality as they provide benefits, such include land use conflict mitigation and the shading effects of PV panels lessening the rate of water evaporation (Connolly et al., 2010; Akella et al., 2009; IRENA, 2020). Due to the cooling effect caused by water, FSPVs overcome the thermal losses leading to better performance. An experimental report claims that FSPV can enhance efficiency to 11% more than GMPV (Sahin et al., 2020). On the other side, global solar policies were also in consideration for FSPV (Solangi et al., 2011). This installation approach was already influential in countries like India, Singapore, Japan, Korea, and others; additionally, it can be effective in countries that do not have enough land to install large PV plants (Deo and Tiwari, 2014; Gotmare and Prayagi, 2014; Sahu et al., 2016; Charles Lawrence Kamuyu et al., 2018). The FSPV system generally consists of several components such include pontoons, floats, mooring systems, solar PV modules, connectors, cables, power converters, and power transmission systems (Choi, 2014; Dash and Gupta, 2015). A schematic representation of a typical FSPV system is illustrated in Figure 1A. Depending upon the PV module installation approach, FSPVs can be fixed and tracking (1 or 2-axis tracking) (Choi et al., 2016; Bjørneklett, 2018); additionally, there exist few other classifications based on different components of FSPV such as floating platforms, anchoring and mooring, and electrical configuration, see Figure 1B.

Several studies have been conducted on FSPV to analyze performance feasibility. A 10 MW FSPV project was implemented in ref (Goswami et al., 2019) that considered the technical and economic parameters to perform the feasibility analysis. The outcome showed that the FSPV system could generate 10.2% more power than land-based PV plants. As a result, the levelized tariff cost of FSPV is reduced to 39% than other types of PV plants. A combined operation of the 2 GW FSPV plant and a 1 GW pumped storage power (PSP) system is proposed in ref (Liu et al., 2019) to achieve maximum power efficiency and minimum power imbalances. The experiment includes the genetic algorithm to analyze the operation. The outcomes illustrate the improved power output as 9112.74 MW and the reduced energy imbalance as 23.06 MW. The FSPV implementation is demonstrated in ref (Oliveira-Pinto and Stokkermans, 2020), which aims to relate the technical and economic feasibility using simulation models. Results from (Oliveira-Pinto and Stokkermans, 2020) show a 1.81%–2.59% increase in power output and significantly reduced costs. A solar tracking-type FSPV system is demonstrated in (Xu et al., 2019) that adjusts the panel to the accurate positions using the mechanical approach to absorb maximum solar energy. The system minimized system costs as it does not require motors to adjust panel angles. A 3 MW FSPV system simulation implementation is proposed in (Perera and Wen, 2020) that analyzes the system’s technical, economic, and environmental feasibility; additionally, they also simulated the combined hydropower with FSPV making the cumulative capacity 15 MW. Techno-economic analysis of an FSPV plant and a wind farm is carried out in (Golroodbari et al., 2021), incorporating cable pooling to enhance solar capability. The research proves that the combined operation lessens cost with improved efficiency. They also worked on solar and wind resources’ effects on power generation. Techno-economic analysis of 1 MW FSPV plants in Korea is proposed in (Song and Choi, 2016), including a fish-eye lens and digital elevation model for shading analysis. The weather data and system operation is evaluated in the system advisor model (SAM). The simulation outcomes show that the annual power generation is 971.57 MW, and the net present value is $897,000 in 12.3 years. A combined integration of hydroelectric power and the FSPV plant is implemented in (Rauf et al., 2020), which incorporates an optimization model to maximize power output and reach peak demand. The MATLAB platform evaluates the optimization model to analyze the technical feasibility. The results claim an additional 3.5% power output for the combined operation. The study continues a technical analysis of power output and does not provide any economic or environmental views. Another combined hydroelectric power and FSPV plant operation are demonstrated in (Farfan and Breyer, 2018), aiming to reach peak demand during irradiation hours. The FSPV plant prevents the water evaporation of the reservoir from facilitating the hydropower operation. The study directs some restrictions of FSPV operation due to sessional and environmental effects. Technical analysis of an FSPV plant is represented in (Ho et al., 2015) that incorporates the double water-saturated microencapsulated phase change material (MEPCM) layer. The study analyzes the effect of integrating the MEPCM layer with the FSPV panel and the result of temperature control. The simulation result shows that the power efficiency with the MEPCM layer is increased by 2.03% during summer than the non-layered system. The reliability of the FSPV plant is proposed in (Kim et al., 2019), which determines the water level of the reservoirs through OpenAPI. The outcomes of the study provide a preliminary analysis of FSPV technical operations. A thin film FSPV concept is proposed in (Trapani and Millar, 2014) that is expected to enhance the output power by 5%. An economic analysis of the 100MW FSPV plant is demonstrated in (Zhou et al., 2009) that considers investment, maintenance cost, lifespan, payback period, operation cost, inflation rate, the rate of interest, the minimum attractive rate of return (MARR), and so on as essential parameters. The experimental outcome shows that the MARR and the interest rate increased by 8% and 2%, respectively.

Based on the literature review mentioned in Section 1.2 on the performance of FPSV, it is clear that several research works have been performed to investigate the FSPV feasibility. They mainly showed how superior FSPVs perform compared to counterpart GMPVs, but we believe there are still opportunities for further power performance enhancement. This is because most studies on FSPV performance in literature ignored systems innovation concepts that would potentially help in improving performance, for instance, cleaning systems integration, cooling systems integration apart from natural cooling, and technology upgrades in the system components (e.g., bifacial as it captures reflected components of solar radiation given water is good reflecting medium).

We also understood that individual analyses, i.e., technical, economic, and environmental, are pretty standard, and the combined analysis (i.e., FSPV system feasibility considering all analyses earlier mentioned) is infrequent, even on the industry side, which provides services to clients. On the other side, the industry’s delivery of FSPV installation service to clients is often questioned, highlighting that FSPV modeling is compromised, leading to false promises on performance and feasibility. This might be true given the lack of modeling tools specific to FSPV systems. Also, most studies ignored many key parameters that need to be accounted for while modeling, for instance, degradation and risks to the water ecosystem and other social problems. Additionally, the indicators related to lifecycle sustainability are less given importance. To put this more straightforwardly, the life cycle assessment is somewhat touched on in academia and not touched by industry service providers when delivering service to clients. In some studies, greenhouse gas emission (GHG) reduction based on electricity emission factors benchmarked to fossil fuel-based power plants was only considered in environmental assessment, which may not be suitable under current environmental, social, and governance (ESG) criteria. These insights provide that there is a robust research gap from the point of systems and approach that enhance FSPV power performance, the need for carrying out the combined analysis or integrated assessment for feasibility analysis, and the need for advancing simulation tools specific to FSPV possibly with a framework and conceptual software model.

With this hypothesis, we formulated this review to explore better feasibility assessment approaches for FSPV. For this, we first reviewed various lifecycle-based performance indicators and then identified key indicators that play a significant role in performance enhancement, followed by energy enhancement options. Second, a holistic performance framework that should be practiced in academia and industry is proposed based on the indicators. Third, we reviewed multiple modeling approaches and tools available in the literature to see whether FSPVs can be simulated (with and without adding these performance enhancement strategies), along with the respective tool capability and functionality as per our lifecycle-based performance indicators. Lastly, in the fourth step, based on the outcome of the third step, assessment approaches for FSPV and feasibility tool advancement by proposing a conceptual simulation tool specific to the FSPV project are discussed.

To better understand the FSPV project feasibility, while planning, one should investigate multiple indicators covering the lifecycle of the FSPV and various other intra/interdependent factors. The essential indicators identified for FSPV project feasibility are given in Figure 2; these are classified under the techno-economic-environmental and social analysis category.

From the indicators highlighted in Section 2.1 a few indicators related to solar PV arrays can be improved with the appropriate introduction of solar panel cooling and cleaning strategies. At the same time, PV array energy can be further enhanced by replacing the conventional monofacial solar PV modules with bifacial solar PV modules.

Among all the modeling approaches, mathematical modeling is quite popular and very traditional. There are already very well-established modeling options for PV systems. These can be adopted for FSPV with slight adjustments in parameter modeling, for instance, temperature models specific to FSPV. Following this modeling, performance indicators can be estimated as per IEA standards. Similarly, economic modeling is quite well-established and can be done mathematically. However, coming to environmental and social analysis, it is quite difficult for mathematical models as they need a lot of data and modeling from a life cycle perspective. Nevertheless, some methods, like embodied energy and carbon, can be adopted. Social analysis as per indicators mentioned in Table 2 can be done by conducting a survey.

The integrated assessment approach shown in Figure 7 can be applied to understand the FSPV feasibility holistically. In this approach, the first system design has to be done separately, for which technical-economical-environmental-social analysis has to be done by picking the right tools. While doing each analysis, data collection and processing is again a crucial step. For instance, in the case of techno-economic analysis, existing tools mentioned in Table 6 with slight modifications can be used. For environmental analysis, first the life cycle inventory data sets have to be created following the guidelines for each component in FSPV. Once the LCI is created, one can use tools like SimaPro (2023); OpenLCA (2022); GaBi (2023) for doing the life cycle assessment. For social analysis, the survey can be conducted, and the surveyed data can be used in excel for assessment. In integrated assessments, there is a possibility for scenario and sensitivity analysis, and based on that system can be optimized or redesigned.

The last model is the proposed conceptual simulation tool for advancing the FSPV simulations. The main objective behind this conceptualization was to bring all analysis (techno-economic-environmental and social) under one roof. In Figure 8, a twelve-window simulation tool is presented. Each window of the simulation tool is briefly explained below: