This is an index of energy articles.

A

Activation energy In chemistry and physics, activation energy is the minimum amount of energy that must be provided for compounds to result in a chemical reaction. The activation energy (''E''a) of a reaction is measured in joules per mole (J/mol), kilojoules p ...

- Alternative energy - Alternative energy indexes -

American Museum of Science and Energy The American Museum of Science and Energy (AMSE) is a science museum in Oak Ridge, Tennessee, designed to teach children and adults about energy, especially nuclear power, and to document the role Oak Ridge played in the Manhattan Project. The mus ...

(AMSE) - Anisotropy energy -

Atomic energy Atomic energy or energy of atoms is energy carried by atoms. The term originated in 1903 when Ernest Rutherford began to speak of the possibility of atomic energy. Isaac Asimov, ''Atom: Journey Across the Sub-Atomic Cosmos'', New York:1992 Plume, ...

B

Binding energy In physics and chemistry, binding energy is the smallest amount of energy required to remove a particle from a system of particles or to disassemble a system of particles into individual parts. In the former meaning the term is predominantly use ...

- Bioenergy - Black hole -

Breeder reactor A breeder reactor is a nuclear reactor that generates more fissile material than it consumes. Breeder reactors achieve this because their neutron economy is high enough to create more fissile fuel than they use, by irradiation of a fertile mate ...

- Brown energy

C

Characteristic energy In astrodynamics, the characteristic energy (C_3) is a measure of the excess specific energy over that required to just barely escape from a massive body. The units are length2 time−2, i.e. velocity squared, or energy per mass. Every object in ...

- Conservation of energy -

Consol Energy Consol Energy Inc. is an American energy company with interests in coal headquartered in the suburb of Cecil Township, in the Southpointe complex, just outside Pittsburgh, Pennsylvania. In 2017, Consol formed two separate entities: CNX Resour ...

D

Dark energy In physical cosmology and astronomy, dark energy is an unknown form of energy that affects the universe on the largest scales. The first observational evidence for its existence came from measurements of supernovas, which showed that the univ ...

Decay energy The decay energy is the energy change of a nucleus having undergone a radioactive decay. Radioactive decay is the process in which an unstable atomic nucleus loses energy by emitting ionizing particles and radiation. This decay, or loss of energy ...

Direct Energy Direct Energy LP is a North American retailer of energy and energy services. The company was founded in Toronto in 1986 and now has more than four million customers in Canada and the United States. Direct Energy is a subsidiary of NRG Energy. His ...

- Dirichlet's energy - Dyson's sphere

E

Ecological energetics Energy flow is the flow of energy through living things within an ecosystem. All living organisms can be organized into producers and consumers, and those producers and consumers can further be organized into a food chain. Each of the levels wi ...

- Electric Bond and Share Company - Electric potential energy - Electrochemical energy conversion -

Embodied energy Embodied energy is the sum of all the energy required to produce any goods or services, considered as if that energy was incorporated or 'embodied' in the product itself. The concept can be useful in determining the effectiveness of energy-produ ...

Encircled energy The optical, optics term encircled energy refers to a measure of concentration of energy in an optical image, or projected laser beam, laser at a given range. If a single star is brought to its sharpest Focus (optics), focus by a lens (optics), len ...

Energy In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of hea ...

- Energy accidents -

Energy accounting Energy accounting is a system used to measure, analyze and report the energy consumption of different activities on a regular basis. This is done to improve energy efficiency, and to monitor the environment impact of energy consumption. Energy man ...

Energy amplifier In nuclear physics, an energy amplifier is a novel type of nuclear power reactor, a subcritical reactor, in which an energetic particle beam is used to stimulate a reaction, which in turn releases enough energy to power the particle accelerator and ...

Energy applications of nanotechnology As the world's energy demand continues to grow, the development of more efficient and sustainable technologies for generating and storing energy is becoming increasingly important. According to Dr. Wade Adams from Rice University, energy will b ...

Energy balance (biology) In biology, energy homeostasis, or the homeostatic control of energy balance, is a biological process that involves the coordinated homeostatic regulation of food intake (energy inflow) and energy expenditure (energy outflow). The human brain, parti ...

Energy bar Energy bars are supplemental bars containing cereals, micronutrients, and flavor ingredients intended to supply quick food energy. Because most energy bars contain added protein, carbohydrates, dietary fiber, and other nutrients, they may be ma ...

- Energy barrier -

Energy being An energy being or astral being is an alleged life form that is composed of energy rather than matter. They appear in myths/legends, paranormal/UFO accounts, and in various works of speculative fiction, also in some religions it's believed that ...

- Energy carrier - Energy Catalyzer - Energy cell -

Energy charge The adenylate energy charge is an index used to measure the energy status of biological cells. ATP or Mg-ATP is the principal molecule for storing and transferring energy in the cell : it is used for biosynthetic pathways, maintenance of transmem ...

- Energy conservation - Energy conversion efficiency - Energy crop - Energy current - Energy density - Energy-depth relationship in a rectangular channel - Energy development -

Energy-dispersive X-ray spectroscopy Energy-dispersive X-ray spectroscopy (EDS, EDX, EDXS or XEDS), sometimes called energy dispersive X-ray analysis (EDXA or EDAX) or energy dispersive X-ray microanalysis (EDXMA), is an analytical technique used for the elemental analysis or chemi ...

- Energy distance - Energy drift - Energy drink - Energy efficiency gap -

Energy-Efficient Ethernet In computer networking, Energy-Efficient Ethernet (EEE) is a set of enhancements to twisted-pair, twinaxial, backplane, and optical fiber Ethernet physical-layer variants that reduce power consumption during periods of low data activity. The ...

Energy-efficient landscaping Energy-efficient landscaping is a type of landscaping designed for the purpose of conserving energy. There is a distinction between the embedded energy of materials and constructing the landscape, and the energy consumed by the maintenance and ope ...

- Energy elasticity -

Energy engineering Energy engineering or Energy Systems Engineering is a broad field of engineering dealing with energy efficiency, energy services, facility management, plant engineering, environmental compliance, sustainable energy and renewable energy tec ...

Energy (esotericism) Proponents and practitioners of various esoteric forms of spirituality and alternative medicine refer to a variety of claimed experiences and phenomena as being due to "energy" or "force" that defy measurement and thus are distinguished from t ...

- Energy expenditure -

Energy factor An energy factor is a metric used in the United States to compare the energy conversion efficiency of residential appliances and equipment. The energy factor is currently used for rating the efficiency of water heaters, dishwashers, clothes washer ...

Energy field disturbance Energy field disturbance is a pseudoscientific concept rooted in alternative medicine. Supporters of this concept believe it concerns the disruptance of a metaphysical biofield that permeates the body, resulting in poor emotional or physiological ...

Energy filtered transmission electron microscopy Energy-filtered transmission electron microscopy (EFTEM) is a technique used in transmission electron microscopy, in which only electrons of particular kinetic energies are used to form the image or diffraction pattern. The technique can be used to ...

Energy transfer In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat ...

Energy flow (ecology) Energy flow is the flow of energy through living things within an ecosystem. All living organisms can be organized into producers and consumers, and those producers and consumers can further be organized into a food chain. Each of the levels wi ...

- Energy flux - Energy forestry -

Energy functional The energy functional is the total energy of a certain system, as a functional of the system's state. In the energy methods of simulating the dynamics of complex structures, a state of the system is often described as an element of an appropriate ...

Energy gel Energy gels are carbohydrate gels that provide energy for exercise and promote recovery, commonly used in endurance events such as running, cycling, and triathlons. Energy gels are also referred to as endurance gels, sports gels, nutritional ge ...

Energy harvesting Energy harvesting (EH, also known as power harvesting or energy scavenging or ambient power) is the process by which energy is derived from external sources (e.g., solar power, thermal energy, wind energy, salinity gradients, and kinetic ener ...

Energy input labeling The term energy input labeling involved producers of goods and services determining how much energy is used to produce their product, and then including that information on their product packaging. Energy input labeling is sometimes known by the ac ...

Energy landscape An energy landscape is a mapping of possible states of a system. The concept is frequently used in physics, chemistry, and biochemistry, e.g. to describe all possible conformations of a molecular entity, or the spatial positions of interacting m ...

Energy level A quantum mechanical system or particle that is bound—that is, confined spatially—can only take on certain discrete values of energy, called energy levels. This contrasts with classical particles, which can have any amount of energy. The t ...

Energy level splitting In quantum physics, energy level splitting or a split in an energy level of a quantum system occurs when a perturbation changes the system. The perturbation changes the corresponding Hamiltonian and the outcome is change in eigenvalues; several ...

Energy management software Energy Management Software (EMS) is a general term and category referring to a variety of energy-related software applications which may provide utility bill tracking, real-time metering, building HVAC and lighting control systems, building simulat ...

Energy management system An energy management system (EMS) is a system of computer-aided tools used by operators of electric utility grids to monitor, control, and optimize the performance of the generation or transmission system. Also, it can be used in small scale syste ...

Energy–maneuverability theory Energy–maneuverability theory is a model of aircraft performance. It was developed by Col. John Boyd, a fighter pilot, and Thomas P. Christie, a mathematician with the United States Air Force, and is useful in describing an aircraft's performan ...

- Energy Manufacturing Co. Inc -

Energy medicine Energy medicine is a branch of alternative medicine based on a pseudo-scientific belief that healers can channel "healing energy" into a patient and effect positive results. Practitioners use a number of names including various synonyms for m ...

Energy–momentum relation In physics, the energy–momentum relation, or relativistic dispersion relation, is the relativistic equation relating total energy (which is also called relativistic energy) to invariant mass (which is also called rest mass) and momentum. It is t ...

Energy monitoring and targeting Energy monitoring and targeting (M&T) is an energy efficiency technique based on the standard management axiom stating that “you cannot manage what you cannot measure”. M&T techniques provide energy managers with feedback on operating practic ...

Energy Probe Energy Probe is a non-governmental social, economic, and environmental policy organization based in Toronto, Canada known for denying man-made climate change. It was founded in 1970 as a sister project of Pollution Probe. In 1980, the two organi ...

- Energy profile (chemistry) -

Energy quality Energy quality is a measure of the ease with which a form of energy can be converted to useful work or to another form of energy: i.e. its content of thermodynamic free energy. A high quality form of energy has a high content of thermodynamic f ...

Energy recovery ventilation Energy recovery ventilation (ERV) is the energy recovery process in residential and commercial HVAC systems that exchanges the energy contained in normally exhausted air of a building or conditioned space, using it to treat (precondition) the in ...

Energy security Energy security is the association between national security and the availability of natural resources for energy consumption. Access to (relatively) cheap energy has become essential to the functioning of modern economies. However, the uneven d ...

Energy (signal processing) In signal processing, the energy E_s of a continuous-time signal ''x''(''t'') is defined as the area under the squared magnitude of the considered signal i.e., mathematically :E_ \ \ = \ \ \langle x(t), x(t)\rangle \ \ = \int_^dt :Unit of E_sw ...

- Energy Slave -

Energy Star Energy Star (trademarked ''ENERGY STAR'') is a program run by the U.S. Environmental Protection Agency (EPA) and U.S. Department of Energy (DOE) that promotes energy efficiency. The program provides information on the energy consumption of pr ...

- Energy statistics - Energy Storage Challenge - Energy storage -

Energy system An energy system is a system primarily designed to supply energy-services to end-users. The intent behind energy systems is to minimise energy losses to a negligible level, as well as to ensure the efficient use of energy. The IPCC Fifth ...

Energy technology Energy development is the field of activities focused on obtaining sources of energy from natural resources. These activities include production of renewable, nuclear, and fossil fuel derived sources of energy, and for the recovery and reuse ...

Energy tower (downdraft) The energy tower is a device for producing electrical power. The brainchild of Dr. Phillip Carlson, expanded by Professor Dan Zaslavsky from the Technion. Energy towers spray water on hot air at the top of the tower, making the cooled air fall ...

Energy transfer upconversion Energy Transfer Upconversion or ETU is a physical principle (most commonly encountered in solid-state laser physics) that involves the excitation of a laser-active ion to a level above that which would be achieved by simple absorption of a pump pho ...

- Energy transformation -

Energy value of coal The energy value of coal, or fuel content, is the amount of potential energy coal contains that can be converted into heat. This value can be calculated and compared with different grades of coal and other combustible materials, which produce diffe ...

- Energy vortex (stargate) -

Enthalpy Enthalpy , a property of a thermodynamic system, is the sum of the system's internal energy and the product of its pressure and volume. It is a state function used in many measurements in chemical, biological, and physical systems at a constant ...

Entropy Entropy is a scientific concept, as well as a measurable physical property, that is most commonly associated with a state of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodynam ...

Equipartition theorem In classical statistical mechanics, the equipartition theorem relates the temperature of a system to its average energies. The equipartition theorem is also known as the law of equipartition, equipartition of energy, or simply equipartition. T ...

E-statistic Energy distance is a statistical distance between probability distributions. If X and Y are independent random vectors in ''R''d with cumulative distribution functions (cdf) F and G respectively, then the energy distance between the distribution ...

Exertion Exertion is the physical or perceived use of energy.Newton's Third Law, Elert, Glenn. “Forces.” ''Viscosity – The Physics Hypertextbook'', physics.info/newton-first/. Exertion traditionally connotes a strenuous or costly ''effort'', resulting ...

F

Fermi energy The Fermi energy is a concept in quantum mechanics usually referring to the energy difference between the highest and lowest occupied single-particle states in a quantum system of non-interacting fermions at absolute zero temperature. In a Fermi ga ...

- Forms of energy - Fuel -

Fusion power Fusion power is a proposed form of power generation that would generate electricity by using heat from nuclear fusion reactions. In a fusion process, two lighter atomic nuclei combine to form a heavier nucleus, while releasing energy. Devices de ...

G

Geothermal energy -

Gravitational energy Gravitational energy or gravitational potential energy is the potential energy a massive object has in relation to another massive object due to gravity. It is the potential energy associated with the gravitational field, which is released (conver ...

Gravitational potential In classical mechanics, the gravitational potential at a location is equal to the work (energy transferred) per unit mass that would be needed to move an object to that location from a fixed reference location. It is analogous to the electric ...

H

History of energy -

Hydroelectricity Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined an ...

I

Interaction energy -

Intermittent energy source Variable renewable energy (VRE) or intermittent renewable energy sources (IRES) are renewable energy sources that are not dispatchable due to their fluctuating nature, such as wind power and solar power, as opposed to controllable renewable ener ...

- Internal energy - Invariant mass - Ionization energy

J

Josephson energy

K

Kinetic energy In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acc ...

L

Latent heat Latent heat (also known as latent energy or heat of transformation) is energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process — usually a first-order phase transition. Latent heat can be underst ...

M

Magnetic confinement fusion Magnetic confinement fusion is an approach to generate thermonuclear fusion power that uses magnetic fields to confine fusion fuel in the form of a plasma. Magnetic confinement is one of two major branches of fusion energy research, along with ...

Marine energy Marine energy or marine power (also sometimes referred to as ocean energy, ocean power, or marine and hydrokinetic energy) refers to the energy carried by ocean waves, tides, salinity, and ocean temperature differences. The movement of water in ...

Mass–energy equivalence In physics, mass–energy equivalence is the relationship between mass and energy in a system's rest frame, where the two quantities differ only by a multiplicative constant and the units of measurement. The principle is described by the physici ...

Mechanical energy In physical sciences, mechanical energy is the sum of potential energy and kinetic energy. The principle of conservation of mechanical energy states that if an isolated system is subject only to conservative forces, then the mechanical energy is ...

- Möbius energy -

Muzzle energy Muzzle energy is the kinetic energy of a bullet as it is expelled from the muzzle of a firearm. Without consideration of factors such as aerodynamics and gravity for the sake of comparison, muzzle energy is used as a rough indication of the de ...

N

Negative energy Negative energy is a concept used in physics to explain the nature of certain fields, including the gravitational field and various quantum field effects. Gravitational potential energy Gravitational potential energy can be defined as being n ...

Nuclear fusion Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles ( neutrons or protons). The difference in mass between the reactants and products is manife ...

Nuclear power Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced ...

Nuclear reactor A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat fr ...

O

Orders of magnitude (energy) This list compares various energies in joules (J), organized by order of magnitude. Below 1 J 1 to 105 J 106 to 1011 J 1012 to 1017 J 1018 to 1023 J Over 1023 J } , - , 1050 , , ≳1050 J , Upper limit of 'apparent'/isotropic energy ...

Osmotic power Osmotic power, salinity gradient power or blue energy is the energy available from the difference in the salt concentration between seawater and river water. Two practical methods for this are reverse electrodialysis (RED) and pressure retarde ...

P

Photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...

- Potential energy - Power (physics) -

Primary energy Primary energy (PE) is an energy form found in nature that has not been subjected to any human engineered conversion process. It is energy contained in raw fuels, and other forms of energy, including waste, received as input to a system. Prim ...

Q

Qi - Quasar

R

Relativistic jet - Renewable energy -

Rotational energy Rotational energy or angular kinetic energy is kinetic energy due to the rotation of an object and is part of its total kinetic energy. Looking at rotational energy separately around an object's axis of rotation, the following dependence on the ob ...

S

Seismic scale Seismic magnitude scales are used to describe the overall strength or "size" of an earthquake. These are distinguished from seismic intensity scales that categorize the intensity or severity of ground shaking (quaking) caused by an earthquake at ...

- Solar energy -

Solar thermal energy Solar thermal energy (STE) is a form of energy and a technology for harnessing solar energy to generate thermal energy for use in industry, and in the residential and commercial sectors. Solar thermal collectors are classified by the United St ...

Sound energy In physics, sound energy is a form of energy that can be heard by living things. Only those waves that have a frequency of 16 Hz to 20 kHz are audible to humans. However, this range is an average and will slightly change from individ ...

Specific energy Specific energy or massic energy is energy per unit mass. It is also sometimes called gravimetric energy density, which is not to be confused with energy density, which is defined as energy per unit volume. It is used to quantify, for example, sto ...

Specific kinetic energy Specific kinetic energy is kinetic energy of an object per unit of mass. It is defined as \begin e_k = \frac \end v^2 . Where e_k is the specific kinetic energy and v is velocity. It has units of J/kg, which is equivalent to m2/s2. Energy ( ...

Specific orbital energy In the gravitational two-body problem, the specific orbital energy \varepsilon (or vis-viva energy) of two orbiting bodies is the constant sum of their mutual potential energy (\varepsilon_p) and their total kinetic energy (\varepsilon_k), divide ...

- Surface energy

T

Thermodynamic free energy The thermodynamic free energy is a concept useful in the thermodynamics of chemical or thermal processes in engineering and science. The change in the free energy is the maximum amount of work that a thermodynamic system can perform in a process ...

Threshold energy In particle physics, the threshold energy for production of a particle is the minimum kinetic energy that must be imparted to one of a pair of particles in order for their collision to produce a given result. If the desired result is to produce a t ...

Tidal power Tidal power or tidal energy is harnessed by converting energy from tides into useful forms of power, mainly electricity using various methods. Although not yet widely used, tidal energy has the potential for future electricity generation. Ti ...

Turbulence kinetic energy In fluid dynamics, turbulence kinetic energy (TKE) is the mean kinetic energy per unit mass associated with eddies in turbulent flow. Physically, the turbulence kinetic energy is characterised by measured root-mean-square (RMS) velocity fluctuat ...

U

Units of energy Energy is defined via work, so the SI unit of energy is the same as the unit of work – the joule (J), named in honour of James Prescott Joule and his experiments on the mechanical equivalent of heat. In slightly more fundamental terms, is ...

- Universe of Energy

V

Vacuum energy Vacuum energy is an underlying background energy that exists in space throughout the entire Universe. The vacuum energy is a special case of zero-point energy that relates to the quantum vacuum. The effects of vacuum energy can be experiment ...

W

Watt meter -

Work (physics) In physics, work is the energy transferred to or from an object via the application of force along a displacement. In its simplest form, for a constant force aligned with the direction of motion, the work equals the product of the force stre ...

World energy resources and consumption World energy supply and consumption is global production and preparation of fuel, generation of electricity, energy transport, and energy consumption. It is a basic part of economic activity. It includes heat, but not energy from food. This art ...

- World Forum on Energy Regulation

Z

Zero-energy building A Zero Energy Building (ZEB), also known as a Net Zero Energy (NZE) building, is a building with net zero energy consumption, meaning the total amount of energy used by the building on an annual basis is equal to the amount of renewable energy ...

Zero-energy universe The zero-energy universe hypothesis proposes that the total amount of energy in the universe is exactly zero: its amount of positive energy in the form of matter is exactly canceled out by its negative energy in the form of gravity. Some physicist ...

Zero-point energy Zero-point energy (ZPE) is the lowest possible energy that a quantum mechanical system may have. Unlike in classical mechanics, quantum systems constantly fluctuate in their lowest energy state as described by the Heisenberg uncertainty pri ...

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See also