Abstract: A tank-to-tank penstock electric generator system includes a water storage tank having a storage tank lower end with a water release port; a water receiving tank below the level of the water storage tank having a receiving tank upper end with a water receiving opening; a water wheel rotatably mounted on a water wheel mounting structure and having a water wheel rotational axis positioned substantially below the level of the water release port and extending above the level of the water receiving opening; and an electric generator having a generator rotor drivably connected to the water wheel through a drivable connection, so that rotation of the water wheel rotates the generator rotor; so that water flows out of the water storage tank through the water release port, over the water wheel and into the water receiving tank through the water receiving opening, thereby rotating the water wheel and the generator rotor and generating electricity.