What does it cost to get hydroelectric energy?

In simplest terms, although running water is free, harnessing it is an expensive proposition.

To effectively harness water, you must first confine and direct it, usually by means of a dam. Since dams can cost hundreds of millions of dollars, this is a very expensive proposition.

The Hoover dam (known initially as the Boulder dam) cost $49,000,000, and that was in 1936 dollars, when a new car cost less than $600!

Dam-building is also a very dangerous venture, which further drives up the cost; the Hoover dam mentioned above cost almost 100 lives.