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Hydroelectricity
Hydroelectricity, also called hydroelectric power, is electricity generated from moving or falling water; it supplies about 14% of the world's electricity, the most of any renewable source.
Hydroelectricity in Turkey
Hydroelectricity in Turkey, also called hydropower in Turkey, is generated at more than 770 plants with about 32,200 MW installed capacity, the country's largest power resource.
Hydrofining
Hydrofining is a petroleum refining hydrotreating process in which distillates are treated with hydrogen over a catalyst to remove sulfur and nitrogen, first used commercially in the 1950s.
Hydrofoil
A hydrofoil is a boat with underwater wing-like foils that lift its hull clear of the water at speed, cutting drag and enabling higher speeds.
Hydroforming
Hydroforming is a metal-forming process that uses pressurized fluid to expand tubes or sheets against a die, making parts like engine cradles and exhaust components.
Hydrogel
A hydrogel is a three-dimensional network of hydrophilic polymer chains that absorbs and retains water without dissolving, used in contact lenses, drug delivery, and wound care.
Hydrogel actuator
A hydrogel actuator is a soft actuator built from a water-swollen polymer network that converts stimuli like heat, light, or electricity into motion, used in soft robotics and grippers.
Hydrogel ionotronics
Hydrogel ionotronics is a branch of soft electronics in which stretchable, transparent hydrogels serve as ionic conductors, coupling mobile ions with electrons in devices like electronic skin and soft actuators.
Hydrogel optical fibers
Hydrogel optical fibers are light-guiding filaments of water-swollen, cross-linked hydrophilic polymers with tissue-like softness, developed for biosensing, optogenetic stimulation, and photothermal therapy where rigid silica fibers damage tissue.
Hydrogen attack
Hydrogen attack is the irreversible deterioration of steel caused by hydrogen at high temperature, where hydrogen reacts with carbon to form methane inside the metal.
Hydrogen blending
Hydrogen blending is the injection of hydrogen into existing natural gas pipeline networks to transport and burn a hydrogen–natural gas mixture, cutting the carbon intensity of delivered gas.
Hydrogen blistering
Hydrogen blistering is hydrogen damage in which absorbed hydrogen forms gas pockets in a metal, raising surface blisters, typically in steels exposed to hydrogen sulfide.
Hydrogen core network (Germany)
The hydrogen core network (Wasserstoff-Kernnetz) is a Germany-wide long-distance hydrogen pipeline network, approved by the Bundesnetzagentur in October 2024, connecting major hydrogen production, import, and storage locations by 2032.
Hydrogen Council
The Hydrogen Council is a CEO-led global non-profit hydrogen industry alliance founded at Davos in 2017, now uniting about 140 companies from over 20 countries.
Hydrogen crossover
Hydrogen crossover is the undesired transport of hydrogen through the polymer membrane of a PEM water electrolyzer into the oxygen-producing anode, lowering Faradaic efficiency and creating flammable hydrogen-oxygen mixtures.
Hydrogen detonation
Hydrogen detonation is the supersonic combustion of a hydrogen-air or hydrogen-oxygen mixture, a regime of hydrogen cloud explosion distinct from deflagration and from nuclear hydrogen bombs.
Hydrogen economy
The hydrogen economy is a proposed energy system in which low-emissions hydrogen serves as an energy carrier and industrial feedstock for refining, steel, shipping, and heavy transport.
Hydrogen Energy Supply Chain
The Hydrogen Energy Supply Chain (HESC) is an Australian-Japanese pilot that produced hydrogen from Latrobe Valley brown coal and shipped it liquefied to Japan in 2022.
Hydrogen fuel
Hydrogen fuel is hydrogen used as an energy carrier, converted to energy in fuel cells or by combustion, emitting only water at the point of use in a fuel cell.
Hydrogen fuel cell bus
A hydrogen fuel cell bus is a zero-tailpipe-emission bus that generates its electricity onboard from hydrogen, distinguished by refueling in minutes and diesel-comparable range rather than overnight charging.
Hydrogen fueling station
A hydrogen fueling station, also called a hydrogen refueling station (HRS), dispenses hydrogen at high pressure to fuel cell vehicles, ranging from retail pumps to large fleet terminals.
Hydrogen internal combustion engine
A hydrogen internal combustion engine is a piston engine that burns hydrogen like gasoline, emitting no carbon dioxide at the point of use, only water vapor and some nitrogen oxides.
Hydrogen internal combustion engine vehicle
A hydrogen internal combustion engine vehicle burns hydrogen instead of gasoline, producing no tailpipe carbon dioxide though still forming nitrogen oxides, and is aimed at heavy-duty trucks, buses, and off-road equipment.
Hydrogen jet fire
A hydrogen jet fire is a turbulent diffusion flame from an ignited pressurized hydrogen release, controlled by jet momentum and radiating little heat, so it is nearly invisible.
Hydrogen leak detection
Hydrogen leak detection is the use of sensor, optical, acoustic, and tracer-gas methods to find unintended hydrogen releases, which matter because hydrogen is highly flammable and burns with a nearly invisible flame.
Hydrogen liquefier
A hydrogen liquefier is an industrial refrigeration system that cools gaseous hydrogen to about −253 °C, producing liquid hydrogen for rocket propellant and energy transport.
Hydrogen permeation testing
Hydrogen permeation testing is a family of laboratory methods measuring how hydrogen moves through metals, used to assess hydrogen embrittlement and standardized by ISO and ASTM.
Hydrogen pipeline transport
Hydrogen pipeline transport moves gaseous hydrogen through dedicated pipelines, the lowest-cost delivery option over land, though hydrogen embrittlement limits which steel pipes can carry it.
Hydrogen plasma reduction of iron
Hydrogen plasma reduction of iron (HPR), or hydrogen plasma smelting reduction (HPSR), reduces iron ore to iron using hydrogen plasma, emitting water vapor instead of CO2.
Hydrogen plasma smelting reduction
Hydrogen plasma smelting reduction (HPSR) is an experimental ironmaking process that reduces iron ore to liquid iron in one step, emitting water vapor instead of carbon dioxide.