This is a method, and apparatus for practicing the method, for the transfer of geothermal energy and for its use in the production of power, wherein an energy extractor is placed within each of two wells (or within each well of two groups of wells) in such manner that the steam created by a geothermal aquifer into which the well is drilled creates power by passing over the energy extractor in one well (or group) and the steam is further passed beyond the energy extractor within the well and brought out of the well for further power generation, and, in which the condensate returns to the aquifer through the second well, and, wherein a reversible flow arrangement is provided whereby the steam may be alternately taken from the second well (or group) and utilized, with the condensate going back to the first well (or group) in such manner that solids deposited within each well are alternately eliminated, and the heat of the aquifer is uniformly maintained.

In a gravity head geothermal energy conversion system, downwardly flowing working fluid is supplied to a downwell turbine pump in heat transfer relationship to the upwardly flowing geothermal brine. The working fluid which is used to drive the downwell turbine pump is reheated by conveying the working fluid upward in heat transfer relationship with the geothermal brine to a predetermined point.

A geothermal energy system in which a bore hole is drilled into the earth to a depth where a predetermined temperature gradient exists between the earth's surface and the bottom of said bore hole. A liquid refrigerant line passes down the bore hole and connects to an evaporator where the geothermal energy is used to vaporize the refrigerant and from there it passes back up through a high pressure gaseous refrigerant return line to a gas operated turbine located at the earth's surface. The spent refrigerant exiting from the turbine is cooled in a condensing unit and recirculated to the subterranean evaporator unit. The turbine may be used to drive a suitable electrical generator for power production purposes.

Process and equipment serving for the utilization of geothermic energy. In the course of the process water is introduced in a vapor producing pipe driven into the rock under the terrain and by making use of the geothermic heat, water is evaporated and the vapor is utilized such as for the generation of electrical energy. A superatmospheric pressure is set in the vapor producing pipe and a liquid (heat carrying medium) is let to trickle down in the tube, the saturated vapor of which contains 1000 kJ/m.sup.3 of latent heat of evaporation at the adjusted superatmospheric pressure. The equipment includes a vapor producing pipe embedded in the rock under the terrain, a liquid feeding device connected to the upper end of the vapor producing pipe as well as a device to serve for transforming the energy of the extracted vapor. The liquid feeding device comprises a distribution vessel, in which there is an annular spillway directing the liquid in a film-like layer on the inner surface of the vapor producing pipe and enclosing the opening of the distribution vessel ending in the vapor producing pipe.

One or a number of subsoil cavities are employed for the storage or recovery of hot liquids. At the time of heat storage, a heat-transporting liquid is extracted at low temperature at the lower end of each cavity, heated by heat exchange with an external fluid and reinjected at the upper end. At the time of heat recovery, the heat-transporting liquid is extracted at high temperature at the upper end of each cavity, cooled by heat exchange with an external fluid and reinjected at the lower end. The system comprises flow-arresting means for maintaining a minimum operating pressure at the top of each cavity, air or gas purge means, an expansion reservoir and a safety unit for ensuring one-way flow of the heat-transporting liquid from the expansion reservoir to each cavity.