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.