The hydrocarbon dew point is the temperature (at a given pressure) at which the hydrocarbon components of any hydrocarbon-rich gas mixture, such as natural gas, will start to condense out of the gaseous phase.

Hydrocarbon exploration (or oil and gas exploration) is the search by petroleum geologists and geophysicists for deposits of hydrocarbons, particularly petroleum and natural gas, in the Earth using petroleum geology.

An organic compound consisting entirely of hydrogen and carbon.

See Chlorofluorocarbons (CFC’s).

A catalytic chemical process widely used to remove sulfur from natural gas and from refined petroleum products, such as gasoline or petrol, jet fuel, kerosene, diesel fuel, and fuel oils.

Hydrodynamics is the study of liquids in motion.

Conventional hydroelectric dams in most countries are highly regulated, with environmental reviews before construction and operational limits afterwards.

Hydroelectricity, or hydroelectric power, is electricity produced from hydropower.

Hydrofluorocarbons (HFCs) are man-made organic compounds that contain fluorine and hydrogen atoms, and are the most common type of organofluorine compounds. They are frequently used in air conditioning and as refrigerants; R-134a is one of the most commonly used HFC refrigerants. They do not harm the ozone layer as much as the compounds they replace, but they do contribute to global warming

Hydrofoil craft that receives a portion of its lift from a single buoyant pod located below a traditional upper hull. The foils are attached to the pod or “lower hull” which is connected to the upper hull by one or more low-waterplane area struts.

A vessel with underwater wings (hydrofoils) fitted below the hull. The dynamic lift of hydrofoils keeps the hull clear of the water surface while underway.

Hydrogen is the chemical element with the symbol H and atomic number 1.

A hydrogen bond (often informally abbreviated H-bond) is a primarily electrostatic force of attraction between a hydrogen (H) atom which is covalently bound to a more electronegative atom or group, and another electronegative atom bearing a lone pair of electrons—the hydrogen bond acceptor.

As an energy buffer, hydrogen produced via water electrolysis and in combination with underground hydrogen storage or other large-scale storage technologies, could play an important role for the introduction of fluctuating renewable energy sources like wind or solar power.

The hydrogen economy is an envisioned future in which hydrogen is used as a fuel for heat and hydrogen vehicles, for energy storage, and for long distance transport of energy.

Hydrogen embrittlement also known as hydrogen assisted cracking or hydrogen-induced cracking, describes the embrittlement of a metal by diffusible hydrogen.

Hydrogen fuel refers to the use of hydrogen gas (H2) as an energy carrier.

A hydrogen infrastructure is the infrastructure of hydrogen pipeline transport, points of hydrogen production and hydrogen stations (sometimes clustered as a hydrogen highway) for distribution as well as the sale of hydrogen fuel.

Hydrogen pipeline transport is a transportation of hydrogen through a pipe as part of the hydrogen infrastructure.

Hydrogen production is the family of industrial methods for generating hydrogen gas.