Recently, the mining industry has introduced renewable energy technologies to resolve power supply problems at mines operating in polar regions or other remote areas, and to foster substitute industries, able to benefit from abandoned sites of exhausted mines. However, little attention has been paid to the potential placement of floating photovoltaic (PV) systems operated on mine pit lakes because it was assumed that the topographic characteristics of open-pit mines are unsuitable for installing any type of PV systems. This study analyzed the potential of floating PV systems on a mine pit lake in Korea to break this misconception. Using a fish-eye lens camera and digital elevation models, a shading analysis was performed to identify the area suitable for installing a floating PV system. The layout of the floating PV system was designed in consideration of the optimal tilt angle and array spacing of the PV panels. The System Advisor Model (SAM) by National Renewable Energy Laboratory, USA, was used to conduct energy simulations based on weather data and the system design. The results indicated that the proposed PV system could generate 971.57 MWh/year. The economic analysis (accounting for discount rate and a 20-year operational lifetime) showed that the net present value would be $897,000 USD, and a payback period of about 12.3 years. Therefore, we could know that the economic effect of the floating PV system on the mine pit lake is relatively higher than that of PV systems in the other abandoned mines in Korea. The annual reduction of greenhouse gas emissions was analyzed and found to be 471.21 tCO₂/year, which is twice the reduction effect achieved by forest restoration of an abandoned mine site. The economic feasibility of a floating PV system on a pit lake of an abandoned mine was thus established, and may be considered an efficient reuse option for abandoned mines.

As mineral resources are depleted, most mines are typically abandoned and left unattended, resulting in serious social problems that impede sustainable development of these areas. The mining industry has recently introduced the use of renewable energy systems to solve the problems. This study assessed the photovoltaic (PV) potential of an abandoned mine tailings dam at the Sangdong mine in South Korea. A regional shading analysis and field investigations indicated that the usable area for installing the PV system was 44,220 m². The design capacity of the system was 3 MW considering the space available for the PV array. Power generation was simulated by inputting data about the hourly weather, system design, and a site assessment into System Advisor Model software. Simulation results indicated that 3509 MWh of electricity could be generated annually. Moreover, economic feasibility analysis, assuming a 20 year project period, confirmed that the net present value of the PV systems would be $1,903,000 USD. Therefore, installing a 3 MW PV system on the mine tailings dam at the Sangdong mine is feasible and could provide an efficient option for sustainable development of the abandoned mine land.