What are the advantages and disadvantages of hydropower stations?

Advantages: no emission, no pollution during power generation; The fuel cost is zero.

Disadvantages: high cost and difficult immigration; There is little power generation in dry season, and it depends on the weather to eat.

Add some more on this basis

Advantages: The hydraulic unit can start and stop quickly, and it is an excellent standby power supply for peak regulation, frequency modulation and accidents in the power grid; Compared with fossil energy such as coal, hydropower resources are renewable; The reservoir formed by the dam will improve the navigation of the river to some extent.

Disadvantages: Large-scale hydropower stations will cut off rivers, change the natural runoff of rivers, and have a great impact on the ecological environment.