Spanning more than 45 square miles, The Geysers in northern California is the largest geothermal power plant complex in the world. For over a century, its steam has powered innovation, clean energy, and communities across the region.
Geothermal Glossary
Word of the Week – Conduction
Conduction For geothermal applications, this refers to heat transfer in solids where thermal energy flows via microscopic-submicroscopic collisions of particles, which at a macro level is...
Word of the Week – Convection
Convection Refers to heat transfer by fluid circulation in permeable rocks where thermal energy is transported with the flow of hot fluid (water or steam).
Word of the Week – Cooling Tower
Cooling Tower Plant equipment that is used to dissipate heat into air rather than into a river. Cooling is induced in two different ways. For binary plants, dry cooling towers use fans to...
Word of the Week – Cyclone Separator
Cyclone Separator A large cylindrical vessel attached to two-phase production pipelines in geothermal fields that is used to separate dry steam from a fast-moving two-phase fluid. Steam...
Word of the Week – DAS
DAS Distributed Acoustic Sensor. Involves the deployment of fiber optic cable on the surface or in a well, and the detection of small variations in the refractive index of the fiber based...
Word of the Week – DFIT
DFIT Diagnostic Fracture Injection Test. A subsurface well test in which pressure is monitored as a small volume of fluid is injected into a reservoir to develop a hydraulic fracture....
Word of the Week – Diorite
Diorite Dark colored, coarse grained, intrusive rock that contains less silica than granite and that is mostly made of plagioclase, biotite, hornblende, pyroxene, and minor to nil quartz.
Word of the Week – Direct Use
Direct use The utilization of geothermal heat as an energy resource, e.g., to heat (or cool) a building such as a greenhouse, for drying, for manufacturing.
Word of the Week – Directional Drilling
Directional Drilling The practice of steering the trajectory of a well during drilling from vertical to a deviated angle, including horizontal drilling used for oil and gas production from...
Word of the Week – District Heating
District heating A scheme for distributing centrally produced thermal energy via a network of pipes to heat residential and commercial buildings. Such schemes are energy efficient and...
Word of the Week – Dolomite
Dolomite A carbonate mineral similar to calcite in which magnesium partially substitutes for calcium.
Word of the Week – Drill Bit
Drill Bit A tool that is placed on the end of a string of pipe to drill a well. Rotary drill bits are commonly used in oil and gas and geothermal drilling. Coring bits are used to obtain...