# Analysis and Prioritization of the Floating Photovoltaic System Potential for Reservoirs in Korea
## 4 Results  
Figure 7 shows the variation in the mean water depth over one year by distinguishing reservoirs for each province. In Gangwon-do, the number of reservoirs is small, but the reservoirs have a deep water depth. On the other hand, Jeollanam-do has the highest number of water reservoirs but the lowest average water depth. Commonly, the water depth falls rapidly from May to July and tends to recover after July. Figure 8 shows the map of the average water depth for each reservoir over the course of a year. There are a considerable number of reservoirs that are not suitable for floating PV installations, in which the average water depth is less than 5 m. There are many reservoirs in Jeolla-do and Gyeongsang-do, but many reservoirs are low in water depth. The floating PV capacity and power production of each reservoir was calculated considering the solar irradiance, characteristics of the panel, and installation area of the panel. In this study, an additional 11% efficiency was considered for the use of the floating PV. The results for all reservoirs are shown in Table 2, based on the ratio of the installation area for the reservoirs satisfying the water depth requirements assumed above. Only reservoirs with a floating PV capacity of 100 kW or greater were considered. Generally, it is common to install floating PV panels in 10% of the reservoir area. In this case, 1134 reservoirs satisfy the condition, and the total installed capacity of the panels is about 2103 MW, with an annual power production of 2932 GWh. In recent years, a floating PV has been installed for a high percentage of the reservoir area in several cases [31]. If a floating PV is installed over the entire area of the reservoir under extreme assumptions, the total installed capacity of the panel is estimated to be 21,093 MW, and the annual power production is estimated to be 29,409 GWh. Figure 7: The variation of mean water depth over one year for reservoirs of each province. Figure 9a is a map showing the annual electricity usage for the administrative units of Korea in 2017. Metropolitan cities or industrial cities such as Seoul, Ulsan, Incheon, and Busan show relatively high electricity usage, and their annual electricity consumption is about 46,493 GWh, 32,095 GWh, 23,876 GWh, and 20,467 GWh, respectively. Figure 9b shows what percentage of electricity usage can be satisfied when a floating PV is installed in each administrative unit. It is assumed that solar panels are installed in 10% of the reservoir area. It is estimated that Jeolla-do, which has a relatively low power consumption and is favorable for floating PV installation, can supply a large portion of the electric power demand in comparison with other provinces. For example, it is estimated that about 41% of the power demand of Imsil in Jeollabuk-do and 16% of the power demand of Gangjin in Jeollanam-do can be covered by floating PV power generation. Figure 8: The map of the average water depth for each reservoir over a year. Figure 9: (**a**) Map of the annual electricity usage for the administrative units and (**b**) map of the demand-to-supply ratio for electricity usage. Table 3 shows the overall results of reservoir condition, installed floating PV capacity, annual power production, and GHG reduction of each province. It can be seen that Jeoltanamdo, Gyeongsangbuk-do, and Chungcheongnam-do, which have high solar irradiance and a large number of reservoirs, have high power production and high GHG reduction. If a floating PV is installed in 10% of the area for all reservoirs, the expected annual power production is 2932 GWh, and the annual GHG reduction amount is approximately 1,294,450 ton. Assuming that a floating PV is installed in 10% of the reservoir area, the analysis results of the top 10 reservoirs (Figure 10) with the highest power production are shown in Table 4. In this case, a larger reservoir area corresponds to more power generation.