Energy generation from a double wellbore

A method for utilizing groundwater by means of a device comprising:

• an upper well with a vertical or predominantly vertical well shaft and an upper well water reservoir having a first well water level;
• a lower well with a vertical or predominantly vertical well shaft and a lower well water reservoir having a second well water level;
• wherein the second well water level is lower than the first well water level;
• a water line with an inner cavity extending between the upper well water reservoir and the lower well water reservoir comprising:
• a first branch line extending downwardly inside the well shaft of the upper well and into the upper well water reservoir,
• a second branch line extending downwardly inside the well shaft of the lower well and into the lower well water reservoir, and
• a connecting line extending horizontally or predominantly horizontally and connecting the first branch line and the second branch line;
• at least one turbine situated at the level of the connecting line and coupled to the water line for a rotary drive of a turbine rotor by the fluid in the water line;
• and
• an electrical generator comprising a rotor which is mechanically coupled to the at least one turbine rotor and a stator with one or multiple electric output terminals characterized in that the upper well and the lower well are situated concentrically with respect to one another, the lower well being annularly surrounded by the upper well and being separated from same by a ring-shaped water-tight structure;
• characterized by the following steps:
• a) the inner cavity inside the water line is completely filled with water;
• b) when one or multiple valves in the water line are open, the differential pressure between the upper well water reservoir and the lower well water reservoir in the connecting line brings about a flow from the upper well to the lower well, thus driving the turbine;
• c) power is generated in the electrical generator connected to the turbine, and is stored, locally consumed, or supplied to a power grid via a converter or inverter coupled between the one or multiple output terminals of the electrical generator on the one hand and the power grid on the other hand.

A device for utilizing groundwater, characterized by:

• a) an upper well with a vertical or predominantly vertical well shaft and an upper well water reservoir having a first well water level;
• b) a lower well with a vertical or predominantly vertical well shaft which is sealed off from the outside at the level of upper groundwater levels by a water-tight sealing in order to prevent the direct entry of groundwater from an upper groundwater level, and a lower well water reservoir having a second well water level;
• c) wherein the second well water level is lower than the first well water level;
• d) a water line between the upper well water reservoir and the lower well water reservoir comprising:
• a first branch line extending downwardly inside the well shaft of the upper well and into the upper well water reservoir, wherein the outer cross-section of the first branch line is smaller than the inner cross-section of the well shaft of the upper well at least by a clearance so that a water level of the upper well water reservoir outside the first branch is under atmospheric pressure,
• a second branch line extending downwardly inside the well shaft of the lower well and into the lower well water reservoir, wherein the outer cross-section of the second branch line is smaller than the inner cross-section of the well shaft of the lower well at least by a clearance so that a water level of the lower well water reservoir outside the second branch is under atmospheric pressure, and
• a connecting line extending horizontally or predominantly horizontally and connecting the first branch line and the second branch line,
• e) at least one turbine situated at the level of the connecting line and coupled to the water line for a rotary drive of a turbine rotor by the fluid in the water line, which transforms waterpower of the water inside of the connecting line into mechanical power;
• and
• f) an electrical generator comprising a rotor which is mechanically coupled to the at least one turbine rotor and a stator with one or multiple electric output terminals for outputting electric power generated from the mechanical power of the turbine rotor,
• g) wherein the one or multiple electric output terminals of the electrical generator are connected to an energy storage device or to a converter or inverter which is coupled to a power grid for delivering electric power to the power grid characterized in that the upper well and the lower well are situated concentrically with respect to one another, the lower well being annularly surrounded by the upper well and being separated from same by a ring-shaped water-tight structure.