US-12624682-B2 - Combined power generation using geothermal and solar energy

US12624682B2US 12624682 B2US12624682 B2US 12624682B2US-12624682-B2

Abstract

Systems and methods are presented for enhancing energy production and storage by integrating solar energy with geothermal processes. In certain embodiments, a hybrid geothermal/solar system increases energy yield from a closed loop geothermal system, stores heat in a wellbore, enhances power generation from geothermal brine, and/or facilitates carbon dioxide sequestration or conversion to fuel, all preferably utilizing solar energy as a supplemental heat source.

Inventors

Patrick Soon-Shiong

Assignees

NANT HOLDINGS IP, LLC

Dates

Publication Date: 20260512
Application Date: 20250117

Claims (19)

1 . A method of generating electrical energy, comprising: heating a working fluid in a closed loop geothermal system using solar energy; wherein the closed loop geothermal system comprises a closed loop working fluid circuit having (a) a topside portion that is thermally coupled to a power cycle and (b) a downhole portion that is thermally coupled to a hot formation; wherein the downhole portion is disposed within a wellbore to form an annular space between the wellbore and the downhole portion, and wherein the solar energy heats the working fluid in the downhole portion via a heat transfer fluid in the annular space; and extracting thermal energy from the working fluid using the power cycle to thereby generate electrical energy.
2 . The method of claim 1 , wherein the working fluid is heated in the topside portion of the closed loop geothermal system.
3 . The method of claim 1 , wherein the working fluid is heated before thermal energy is extracted.
4 . The method of claim 1 , wherein the working fluid is heated after thermal energy is extracted and wherein the so heated working fluid is used to generate additional power.
5 . The method of claim 1 , wherein the working fluid is heated via a heat exchanger that is thermally coupled to a solar energy harvesting circuit.
6 . The method of claim 1 , wherein the wellbore is fluidly coupled to the closed loop geothermal system.
7 . The method of claim 1 , wherein the wellbore is thermally insulated by a low-k material comprising sand, a cementitious material, or fiberglass.
8 . The method of claim 1 , wherein the wellbore is co-located with the closed loop geothermal system.
9 . The method of claim 1 , wherein a second wellbore is proximal to the wellbore, wherein the solar energy heats a heat transfer fluid in the second wellbore, and wherein the working fluid in the downhole portion is heated by heat transfer through the hot formation from the second wellbore.
10 . The method of claim 9 , wherein the wellbore and the second wellbore are thermally coupled by a fracture network that is at least partially filled with a thermally conductive material comprising a proppant, water, zinc, or a carbonaceous material.
11 . The method of claim 9 , wherein the wellbore and the second wellbore are part of a wellbore grid comprising a grid controller that controls flow and/or temperature of the heat transfer fluid.
12 . A method of processing a geothermal brine, comprising: producing from a formation a hot geothermal brine; heating a working fluid of a power cycle using heat content of the hot geothermal brine, thereby causing the hot geothermal brine to become a cooled geothermal brine; wherein the power cycle is thermally coupled to a topside portion of a closed loop working fluid circuit, wherein the closed loop working fluid circuit further comprises a downhole portion that is thermally coupled to a hot formation; wherein the downhole portion is disposed within a wellbore to form an annular space between the wellbore and the downhole portion, and wherein solar energy heats the working fluid in the downhole portion via a heat transfer fluid in the annular space; using solar energy to heat the hot geothermal brine and/or the working fluid to thereby increase power generation in the power cycle, and/or using the solar energy to heat the cooled geothermal brine to thereby evaporate water and concentrate a mineral in the cooled geothermal brine.
13 . The method of claim 12 , wherein the hot geothermal brine is produced by a geothermal well or an enhanced geothermal well.
14 . The method of claim 12 , wherein the power cycle is a closed Rankine cycle.
15 . The method of claim 12 , wherein the solar energy heats the hot geothermal brine before or after heating the working fluid.
16 . The method of claim 12 , wherein the solar energy evaporates all water in the cooled geothermal brine to produce a dry mineral product and distilled water.
17 . The method of claim 12 , further comprising a step of processing the cooled geothermal brine by electrochemical enrichment, ultrafiltration, or reverse osmosis to thereby isolate or enrich a metal salt or metal oxide.
18 . The method of claim 17 , wherein the metal salt or metal is a lithium salt or a lithium oxide.
19 . A hybrid geothermal/solar system, comprising: (a) a closed loop geothermal system thermally coupled to a power cycle, and a solar energy harvester that is thermally coupled to the closed loop geothermal system to increase energy yield from the closed loop geothermal system; or (b) a closed loop geothermal system thermally coupled to a heat storage wellbore, wherein a heat transfer fluid in the heat storage wellbore is heated by a solar energy harvester; (c) a geothermal system configured to produce a geothermal brine from a geothermal wellbore, wherein the geothermal system is thermally coupled to a power cycle with a working fluid, and wherein a solar energy harvester is configured to increase power in the power cycle and/or to heat a cooled geothermal brine to thereby evaporate water and concentrate a mineral in the geothermal brine; or (d) a carbon dioxide source that is configured to produce a concentrated carbon dioxide product and that is operationally coupled to a geothermal system and a solar energy harvester, wherein the carbon dioxide source is selected from the group consisting of a direct air capture unit, a decarbonization unit of a fossil fuel power plant, and an acid gas removal unit, wherein the geothermal/solar system is configured to use geothermal and solar energy to sequester the concentrated carbon dioxide product into a geological formation and/or to chemically convert the concentrated carbon dioxide product to a fuel product.

Description

This application claims priority to our U.S. provisional patent application with the Ser. No. 63/622,379, which was filed Jan. 18, 2024, and which is incorporated by reference herein. FIELD OF THE INVENTION The field of the invention is systems and methods for hybrid power systems, especially as it relates to a combination of solar and geothermal energy in the context of power generation and storage, lithium recovery, and/or carbon dioxide capture and chemical synthesis from captured or produced carbon dioxide. BACKGROUND OF THE INVENTION The background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art. All publications and patent applications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply. Renewable energy production has gained significant attention over the last few decades, and efforts to decentralize power generation and/or use of local or regional sources of energy have led to significantly improved power generation systems. In addition to widely accepted and relatively small-scale photovoltaic power generation systems, geothermal and solar energy harvest have become increasingly economically feasible. However, geothermal energy harvest is often limited to relatively low temperatures and slow formation depletion, while solar energy harvest is cyclical in nature and also location dependent for significant power output. To overcome at least some of these disadvantages, power generation schemes have been developed that collocate geothermal and solar energy harvest. For example, U.S. Pat. No. 9,297,367 discloses a combined geothermal and solar thermal organic Rankine cycle (ORC) to produce electric power. Here, the thermal energy from the geothermal fluid is used to power an ORC, which is augmented by solar energy that increases the temperature of the organic working fluid. In most typical embodiments, the collected solar energy assists or supplants geothermal energy in a single hybrid heat exchanger or in multiple sequential heat exchangers. Similarly, U.S. Pat. No. 11,480,160 describes systems and methods for a hybrid geothermal electrical power generation plant that utilizes the heat from a deep geothermal reservoir to vaporize a working fluid and a solar collector is then used to increase the temperature of the working fluid during sunlight hours. In addition, a thermal storage unit may be utilized to increase the temperature of the working fluid during the night. In still another example, WO 2018/102265 describes various systems and methods for power generation in which geothermal heat assists in heating a heat transfer fluid of a concentrated solar power field. As such, at least some of the geothermal energy is transferred to a second working fluid that is also heated by the concentrated solar power field. While such and other hybrid systems provide at least some benefits in terms of electrical power production, the geothermal fluid from a conventional or enhanced geothermal production well must be in most cases re-injected into the formation, and where not re-injected, the spent geothermal fluid will become an environmental liability above ground. To circumvent at least some of the issues associated with conventional or enhanced geothermal production wells, closed loop geothermal systems have been developed as, for example, described in WO 2023/150466 in which a downhole heat exchange system is in enhanced thermal contact with typically hot dry rock at a considerable depth and relatively high temperature. While such systems are generally thought to have desirable heat harvesting and environmental properties, integration with solar energy systems have not been attempted, possibly due to the significant depth of the hot rock formation. Thus, even though various systems and methods of combined power cycles are known in the art, all or almost all of them suffer from several drawbacks. Therefore, there remains a need for improved power generation using geothermal and solar energy. SUMMARY OF THE INVENTION The inventive subject matter is directed to methods and systems for the generation, storage, and enhancement of electrical energy by integrating solar energy with geothermal processes. The inventive subject matter is primarily concerned with the utilization of a closed loop geothermal system that is augmented by solar energy to increase the efficiency and output of power