In 2021, due to the fact that the capacity of rooftop solar PV will be very large, the system will have to cut 65 - 100% of the capacity of plants connected to the 110 kV grid or more - which means that not only solar and wind power plants are "tired" because they cannot generate electricity, but many other power plants with high electricity prices are not mobilized. Therefore, in addition to accelerating the expansion of existing hydropower projects, we need to recalculate the plan to invest in pumped-storage hydroelectricity to overcome the reduction in the mobilization of solar and wind power.