Still in the research stage, solid or molten silicon is though to offer more heat capacity and efficiency.

A vast store of thermal energy is contained within hot – but essentially dry and impervious crystalline basement rocks found almost everywhere deep beneath the Earth's surface.

Input surge current, inrush current or switch-on surge is the maximal instantaneous input current drawn by an electrical device when first turned on.

An injection well is a device that places fluid deep underground into porous rock formations, such as sandstone or limestone, or into or below the shallow soil layer.

A fluid additive specifically designed to decrease the rate of oxidation in metal (rust) and promotion of microbial life (bacteria) in the closed-loop circulating fluid.

In the chemical and process industries, a process has inherent safety if it has a low level of danger even if things go wrong.

An infrared thermometer is a thermometer which infers temperature from a portion of the thermal radiation sometimes called black-body radiation emitted by the object being measured.

Information can be thought of as the resolution of uncertainty; it answers the question of "What an entity is" and thus defines both its essence and the nature of its characteristics.

Inertial confinement fusion is a type of fusion energy research that attempts to initiate nuclear fusion reactions by heating and compressing a fuel target, typically in the form of a pellet that most often contains a mixture of deuterium and tritium.

Inertia is the resistance of any physical object to any change in its velocity.

An inert gas is a gas that does not undergo chemical reactions under a set of given conditions.

Industrial radiography is a modality of non-destructive testing that uses ionizing radiation to inspect materials and components with the objective of locating and quantifying defects and degradation in material properties that would lead to the failure of engineering structures.

Industrial processes are procedures involving chemical, physical, electrical or mechanical steps to aid in the manufacturing of an item or items, usually carried out on a very large scale.

Industrial engineering is an engineering profession that is concerned with the optimization of complex processes, systems, or organizations by developing, improving and implementing integrated systems of people, money, knowledge, information and equipment.

A European directive committing members to control and reduce the impact of emmisions harmful to the environment.

An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding.

An induction generator or asynchronous generator is a type of alternating current electrical generator that uses the principles of induction motors to produce electric power. Induction generators operate by mechanically turning their rotors faster than synchronous speed.

Induction heating is the process of heating an electrically conducting object (usually a metal) by electromagnetic induction, through heat generated in the object by eddy currents.

The tendency of an electrical conductor to oppose a change in the electric current flowing through it.

Induced radioactivity, also called artificial radioactivity or man-made radioactivity, is the process of using radiation to make a previously stable material radioactive.