Energy vs. Exergy — What's the Difference?

In physics, energy is the quantitative property that must be transferred to a body or physical system to perform work on the body, or to heat it. Energy is a conserved quantity; the law of conservation of energy states that energy can be converted in form, but not created or destroyed.

In thermodynamics, the exergy of a system is the maximum useful work possible during a process that brings the system into equilibrium with a heat reservoir, reaching maximum entropy.[1] When the surroundings are the reservoir, exergy is the potential of a system to cause a change as it achieves equilibrium with its environment. Exergy is the energy that is available to be used.

The capacity for work or vigorous activity

(physics) Concentrated or organized energy, which can be exported and do work in the process.

Also energies Exertion of vigor or power

Vitality and intensity of expression

(Informal) A nonphysical force or quality perceived as inhering in a particular place, person, or situation

Usable heat or power

A source of usable power, such as petroleum or coal.

The capacity of a physical system to do work.

A form, amount, or level of this capacity

The impetus behind all motion and all activity.

The capacity to do work.

(physics) A quantity that denotes the ability to do work and is measured in a unit dimensioned in mass × distance²/time² (ML²/T²) or the equivalent.

An intangible, modifiable force (often characterized as either 'positive' or 'negative') believed in some New Age religions to emanate from a person, place or thing and which is (or can be) preserved and transferred in human interactions; shared mood or group habit; a vibe, a feeling, an impression. aura.}}

The external actions and influences resulting from an entity’s internal nature (ousia) and by which it is made manifest, as opposed to that internal nature itself; the aspect of an entity that can affect the wider world and be apprehended by other beings.

A measure of how many actions a player or unit can take; in the fantasy genre often called magic points or mana.

Internal or inherent power; capacity of acting, operating, or producing an effect, whether exerted or not; as, men possessing energies may suffer them to lie inactive.

Power efficiently and forcibly exerted; vigorous or effectual operation; as, the energy of a magistrate.

Strength of expression; force of utterance; power to impress the mind and arouse the feelings; life; spirit; - said of speech, language, words, style; as, a style full of energy.

Capacity for performing work.

(physics) the capacity of a physical system to do work; the units of energy are joules or ergs;

An exertion of force;

Enterprising or ambitious drive;

An imaginative lively style (especially style of writing);

A healthy capacity for vigorous activity;

The federal department responsible for maintaining a national energy policy of the United States; created in 1977