18. Potential and Financial Analysis of the Floating PV in Hydropower Dams of Thailand

Solar power is one of the most widely fascinated renewable energy sources because of its cleanliness, simplicity, abundance, and sustainability. During 2014–2018, the cumulative global floating photovoltaic (FPV) installed capacity has been growing exponentially. The advantages of reducing evaporation, increasing efficiency, and the utilization of the existing infrastructure and the installation of large-scale FPV in hydropower dams have attracted attention. In this work, the FPV systems in Thailand’s hydropower dams are evaluated for their potential power production and economic benefits. Further, the potential energy production was carried out in five cases here. For water surface coverage of 2% and 2.5% on average, the annual energy production was estimated to be 5771 GWh, and 7648 GWh, respectively. The total requirement of the installed capacity of the FPV, to replace the annual hydropower production (about 5511 GWh), could be introduced at 3758 MWp. The installation of the FPV systems covered 5% and 10% of the surface area. It was able to produce the highest electric power, which was more than the energy produced from the existing hydropower plants about 3.5 and 7 times, respectively. All five cases of potential energy production were considered for financial analysis. The highest financial benefit was found in the condition that FPV covers 10% of the surface area. As a result, it was expected to produce 40,096 GWh of electricity per year. This equals the amount of GHG reduction of approximately 24.22 million tCO₂/year. The annual water evaporation reduction of 335.55 million m³/year is worth for agriculture about 27.85 million USD and the electricity production of 50,461 MWh. Based on the evaluation of various financial indicators, namely NPV, IRR, payback period, benefit–cost ratio (BCR), and electricity production cost (LCOE), the economic analysis results can ensure that all the FPV projects studied are profitable. The installation of the FPV system with 170% of DC to AC ratio can obtain more profits in NPV than a facility with a DC to AC ratio of 125%; however, the installation costs rose by about 30%.