Direct thermal-electric conversion for geothermal energy recovery
OwnerLarry Levoyinventor
Life of this patent
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Abstract
Direct conversion systems for in situ conversion of geothermal energy into electricity are described in which thermoelectric generators and/or thermionic convertors directly convert the earth's thermal energy into electrical energy. The choice of a thermoelectric or thermionic system is dictated by the temperature domain of the particular geothermal formation. The basic unit of the described system includes at least two coaxially-intersecting heat pipes, extending between a high temperature geological strata and a low temperature geological strata. Thermal-electric energy conversion devices are positioned within an annulus between the intersecting heat pipes.
Claims39
An in situ system for converting geothermal energy into electricity including a well drilled from ground surface into a high-temperature underground geological strata, comprising in combination,
- a. a first high-temperature heat pipe structure longitudinally aligned parallel the axis of said well having a lower section thermally coupled to said high-temperature geological strata and an upper end section extending toward the ground surface,
- b. a second low-temperature heat pipe structure longitudinally aligned parallel the axis of said well having a lower end section coaxially receiving the upper end section of said high-temperature heat pipe structure defining an annular volume between the upper end section of the high-temperature heat pipe structure and the lower surrounding end section of the low-temperature heat pipe structure,
- c. means for cooling said second low-temperature heat pipe structure,
- d. conversion means positioned within said annulus defined between the upper end section of said high-temperature heat pipe structure and the lower surrounding end section of said low-temperature heat pipe structure for thermally coupling said first high-temperature heat pipe structure to said second low-temperature heat pipe structure and for generating an electric current responsive to a temperature difference between said first and second heat pipe structures, and
- e. means connected to said conversion means for conducting said generated electrical current to the ground surface.
The system of claim 38 wherein said means for preventing said molten magmatic material from extruding up the well toward the ground surface comprises a liquid medium filling said well from said region of molten magmatic medium upward to a point proximate said upper end section of said high temperature heat pipe structure, said liquid medium forming a liquid leg having a sufficient weight to counterbalance pressure forces tending to cause said magmatic material to extrude upward in said well towards the ground surface.
Dependencies are inferred from the claim text.