Hydroelectric generation can use the kinetic energy of water to drive a generator and convert it directly into electrical energy. There is no need to break down the water and then ignite the hydrogen to release heat to produce electricity. It is possible to use hydrogen as a fuel, but electrolysis is the only way to directly break down water. ． It’s very, very energy consuming! ! If hydrogen is to be produced in large quantities, it can be produced by hydrocarbon cracking, carbohydrate decomposition, water and gas separation, etc. There are many ways.
Since water turns into hydrogen and oxygen, this process becomes electrolysis of water, which requires a lot of electricity.
So I don't know how your balloon rises. . . . . . Because although the density of hydrogen is less than that of air, the density of oxygen is greater than that ofe the air. If mixed in a 2:1 ratio, it remains denser than air and cannot rise. . . . . . . Unless you use a plane to fly. Planes also need gasoline.
The best thing is that the process of turning hydrogen and oxygen into water requires ignition. That is, pure hydrogen and oxygen will not turn into water and will have to be ignited. . . Ignition also requires electricity. . . . . . .
Finally, rainwater is actually the free fall of water. You may have seen wind power generation and solar power generation. . . . . But have you ever seen electricity produced when it rains?
With these problems resolved, there is one last problem. . . . . . . . . . . Why is this so embarrassing. . . . . Isn’t it just solar energy? . . . . . .