In its simplest terms, geothermal means earth-heat. It is related to the thermal energy of Earth’s interior. On a large scale, the intensity of this thermal energy increases with depth, that is, the temperature of the Earth increases as we travel closer to its centre. A global average for Earth’s geothermal gradient (temperature increase with depth) is approximately 30°C/km. For example, if we merely removed the outer 3 km of Earth’s outer surface, it would be a sphere 5,000°C at the core, and nearly hot enough to boil water on its surface. Earth contains an incredibly vast amount of thermal energy. This heat is used in a geothermal power plant to drive a steam turbine, which creates electricity. Any leftover heat can also be used in a variety of industrial heating applications.
Co-production offers a sustainable "turn key" conversion of existing Oil and Gas drilling infrastructure by utilizing the hot production water resources already at surface as part of hydrocarbon extraction. It offers well owners and operators a holistic approach for harnessing and selling various forms of energy while diversifying their revenue streams and creating new jobs.
By using Earth’s thermal energy to heat water instead of processes with harmful by-products like coal and nuclear, geothermal energy can produce clean, reliable electricity as long as heat continues to seep from Earth’s interior (as it has for 4.5 billion years). Further, it is sustainable power because once we have extracted the thermal energy from the water or steam, it can be continuously re-injected deep underground to obtain more geothermal heat.
Aside from producing power, we also use hot, geothermal water for heating pools (i.e. hot springs), district heating, agriculture and laundries, to name a few. This is called direct-use geothermal because the heat is used directly from the water to serve a function.