В глоссарии приведены термины, часто используемые в научной и технической литературе по геотермальной энергетике и технологии использования тепла «сухих горных пород» — петротермальной энергетике. Геотермальная энергетика является одной из наиболее перспективных направлений развития альтернативного энергообеспечения.
| baseload plants | Electricity-generating units that are operated to meet the constant or minimum load on the system. the cost of energy from such units is usually the lowest available per unit of electricity. |
| binary-cycle power plant | A geothermal electricity generating plant using heat from lower temperature reservoirs. the technology uses the heat of the geothermal fluid (the "primary fluid") to vaporize a “working fluid” wit... |
| cap rocks | Rocks of low permeability that overlie a geothermal reservoir. |
| cascading heat | A process that uses a stream of geothermal hot water or steam to perform successive tasks requiring lower and lower temperatures. |
| direct use | Use of geothermal heat without first converting it to electricity, such as for space heating and cooling, food preparation, industrial processes, etc. |
| enhanced geothermal systems | Human-made underground geothermal reservoirs that extract geothermal energy from the earth for electricity generation and/or heating applications. egs reservoirs are created by drilling wells and ... |
| flash steam | Steam produced when the pressure on a geothermal liquid is reduced. the depressurization of geothermal fluid to transform it into steam is also called “flashing”. flash steam plants are the most c... |
| geophones | Also known as downhole sensors, these collect high-resolution, real-time micro-seismic data to inform how a geothermal reservoir is growing. geothermal developers need this information to adjust o... |
| geothermal district heating (gdh) | A type of direct use in which a utility system supplies multiple users with hot water or steam from a central plant or well field through a distribution network. |
| geothermal heat pumps | Mature technologies that use the constant temperature of the shallow earth (40–70°f) to provide heating and cooling solutions to buildings wherever the ground can be cost-effectively accessed to d... |
| hydrothermal resource | A conventional geothermal resource (underground system of hot water and/or steam) that can be tapped for electricity generation using existing technologies. |
| known geothermal resource area (kgra) | A region identified by the u.s. geological survey as containing geothermal resources. |
| low temperature resources | Low-temperature geothermal resources are generally considered those below 300°f (150°c), which are ubiquitous in shallow soil, rock, and/or aquifers and have valuable thermal storage properties. l... |
| peaking plants | Electricity generating plants that are operated to meet the peak or maximum load on the system. the cost of energy from such plants is usually higher than from baseload plants. |
| total dissolved solids (tds) | Term used to describe the amount of solid materials in water. |
| vapor-dominated | A geothermal reservoir system in which subsurface pressures are controlled by vapor rather than by liquid. sometimes referred to as a dry-steam reservoir. |
| geofluid | Naturally occurring brine, water, steam or supercritical fluid within earth or at earth’s surface. |
| field r&d | The research and development of a technology in the environment in which it is used. |
| pilot phase | When the system’s product is available for a subset of the market/stakeholders to test (see figures 22-24). |
| pore [rock] | A void space between grains or crystals in a rock that can contain fluids |
| firm [power] | Uninterruptible or guaranteed power. firm power is (a) intended to be available at all times and/or (b) contracted to be supplied by the seller (e.g., law insider, 2023b). |
| heat density | The total amount of heat per unit volume, e.g., joules in one cubic meter of rock. |
| seismic risk | The probability of a natural or human-induced vibration, tremor, or earthquake occurring and causing damage within a given time interval and region (modified after natural resources canada, 2021).... |
| field testing | Testing a technology in the environment in which it is used. |
| matrix [rock] | The solid part of a rock mass which contains the pores, fractures and fluids. |
| direct-contact | A type of surface heat exchanger and a type of condenser inside some geothermal power plants, where heat and mass are transferred out of steam by mixing it with cold water (e.g., dipippo, 2016b).<... |
| heat endowment | The quantity and quality of geothermal heat in a particular geographic region or depth. |
| next-of-a-kind | New geothermal power plants, innovations, or technologies that stem from the first-of-a-kind. they seek to generate better innovations, new plant designs, increases in scale, and lower costs (see ... |
| thermal energy | A category of energy that is stored/contained within a system and responsible for its temperature (khan academy, 2023). it is not the same as heat. |
| first-of-a-kind | The first successful demonstration of a commercial-scale geothermal power plant, innovation or technology (see figure 25). |
| fracture [noun] | A general term for several types of breaks in a rock– for example faults and joints–that may contain pore spaces and fluids. |
| fracture [verb] | The action of cracking, dividing or breaking a rock. |
| geothermal lead | A vaguely-defined underground geological feature that has the potential to contain a geothermal resource. |
| geothermal play | The portion of a geothermal system that contains a heat reservoir, its subsurface working fluid (either native or introduced), and/or a cluster of geothermal fields, geothermal discoveries, geothe... |
| porosity [rock] | The ratio between the volume of pores in a rock and the total volume of the rock, i.e., the capacity of rock to contain a fluid. it is expressed as a percent of rock volume. |
| prototype phase | A simulation of the full system, or a relevant part of it, to determine how parts of the system would behave at larger scales of operation (see figures 22-24). |
| commercial scale | A geothermal project that is generating sufficient heat/power for its customer and sufficient monetary revenue for its investors (see figures 22-24). |
| geothermal field | A localized volume of earth’s crust where a geothermal resource can be extracted from a reservoir by subsurface working fluids and then delivered to a place of use (modified after moeck, 2014). |
| geothermal lease | A deed with which a landowner authorizes exploration for–and production of–geothermal fluids or heat on their license area, usually in consideration of a royalty (modified after law insider, 2023a... |
| igneous province | A region of the earth’s surface and shallow subsurface that contains features related to volcanoes, hot magma, or rocks that contain magmatic and/or naturally radioactive heat. these geological se... |
| permeable [rock] | The ability of a rock to permit the passage of fluids without rupture or displacement of pores (tcd, 1899). the antonym is impermeable. an impermeable rock is sometimes informally called “dry rock... |
| superhot [fluid] | A colloquial term to represent very hot fluids that are produced from deep in earth’s crust. |
| well [geothermal] | A conduit for fluids and information into/out of the thermal reservoir. categories of geothermal well include production well and reinjection well. |
| crystalline [rock] | A variety of rock types formed by crystallization from either |
| impermeable [rock] | A rock that does not permit the passage of fluids through it (oxford learner’s dictionaries, 2023a). |
| induced seismicity | Vibrations, tremors and earthquakes that result from human-induced adjustments of stress and strain within earth. |
| natural seismicity | Vibrations, tremors and earthquakes that occur during natural adjustments of stress and strain within earth’s crust. |
| power [geothermal] | The amount of energy transferred from one component of a geothermal system to another per second. |
| sedimentary [rock] | A variety of rock types formed from fragments of other rocks (e.g., sandstone), made of compressed organic matter (e.g., coal), or made by once-living organisms (e.g., coral limestone). |
| demonstration scale | A limited-scale project that is conducted to demonstrate whether (a) the technology can run successfully at full-scale, (b) data can be generated to verify the company’s modeling of technical perf... |
| geothermal prospect | An underground, geological structure or region with indications that it could contain a hydrothermal reservoir or geothermal reservoir, which could be economically exploited. |
| geothermal resource | The portion of a reservoir’s total geothermal energy that is technically recoverable from the earth. |
| hydrothermal system | The category of geothermal system with convective heat transfer in a naturally occurring geofluid. |
| petrothermal system | A type of geothermal system that is assumed to lack producible geofluids because the subsurface heat exchanger is in impermeable rock below a hydrothermal system/groundwater aquifer (modified afte... |
| superheated [fluid] | A substance that stays in its liquid state above its boiling temperature (roy, 2001) or a pure water steam that exceeds 100℃ (705℉) at earth’s surface. |
| causes could include | (a) movement along rock fractures triggered during reinjection of high-pressure water into a hydrothermal reservoir, (b) reinjected fluid cooling the hot rock or altering the reservoir’s natural s... |
| enthalpy [reservoir] | The measurement of energy or total heat in a thermodynamic system. |
| geothermal discovery | An underground geological structure or region in which a hydrothermal reservoir or geothermal reservoir has been proven, usually with an exploration well. |
| nth-of-a-kind (noak) | Power plants, innovations, or technologies that have been fully designed and optimized. continued cost declines are unlikely at this phase (see figure 25). |
| reservoir management | The operations conducted to obtain the maximum possible economic recovery from a reservoir on the basis of facts, information, and knowledge. sound reservoir-management practice relies on |
| microseismic [events] | Natural seismicity or induced seismicity events within earth that are unnoticed at earth’s surface because they release very little energy, are of very short duration, and are of very low magnitud... |
| permeability creation | The action of various engineering techniques to create fluid pathways within rock, such as fracture enhancement or creation by hydraulic pressure or imposed temperature differential. |
| supercritical [state] | A substance at a temperature and pressure where distinct liquid and gas phases do not exist. this would be above 374℃ (705℉) and above 22 mpa (3205 psi) for water. |
| advection [geothermal] | Rapid heat transfer of heat due to magmatic or hydrous fluids (allen and allen, 2013). |
| geothermal power plant | An industrial facility built on earth’s surface to generate electrical power. |
| conduction [geothermal] | Heat transfer through rocks or fluids that are in contact, but not moving. |
| convection [geothermal] | Heat transfer by the physical movement of molecules (i.e., fluid). the word is used in two contexts |
| open-loop plant [power] | A geothermal plant in which flash geothermal fluids can emit naturally dissolved gas (e.g., nitrogen, hydrogen, carbon dioxide, and/or methane), which comes out of a solution and is released into ... |
| stimulation [reservoir] | Enhancement of a geothermal reservoir or hydrothermal reservoir to increase the amount or speed of subsurface working fluid flow (“reservoir quality”). this can be done by thermal, mechanical, or ... |
| introduced working fluid | Fluid sourced by engineers and introduced into a geothermal reservoir that has insufficient geofluid. |
| subsurface working fluid | The geofluid or the introduced working fluid that is heated in natural or engineered hydrothermal reservoirs, and in open-loop and closed-loop geothermal circuits. |
| base load [power sources] | The power sources that operate continuously to generate reliable and dependable power to consistently meet base load power demand. |
| production well [geothermal] | A type of geothermal well that transmits heat-containing fluids up from a hydrothermal reservoir to earth’s surface (see figure 21). it is also used to collect information about the reservoir and ... |
| proof of concept (poc) phase | A small exercise to test a discrete design idea or assumption (see figures 22-24). |
| superhot rock energy density |
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| closed-loop fluid circulation |
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| open and closed circuit types |
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