Engineering

The perfect recipe for efficient perovskite solar cells

They have improved a process for vertically depositing a solution made from an inexpensive perovskite solute onto a moving substrate below. Not only have they discovered the crucial role played by one of the solvents used, ...

Energy & Green Tech

Model for solar awnings to recharge vehicles

The number of people who own electric vehicles (EVs) is increasing, but they face a conundrum: Unlike those who own gasoline-burning cars, EV owners can't just pop down to the corner gas station for a fill-up. Particularly ...

Energy & Green Tech

Residential batteries for solar power benefit owners and grid

In-home storage of electricity—which can be generated by residential solar panels—can save a homeowner money on their electric bills. It also can benefit the electric company and the power grid. That's the takeaway from ...

Energy & Green Tech

New global 'wind atlas' propels sustainable energy

Wind energy scientists at Cornell University have released a new global wind atlas—a digital compendium filled with documented extreme wind speeds for all parts of the world—to help engineers select the turbines in any ...

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Electric potential energy

Electric potential energy (also known as "electrostatic potential energy") is a potential energy associated with the conservative Coulomb forces within a defined system of point charges. The term "electrostatic potential energy" is preferred here because it seems less likely to be misunderstood. The reference zero is usually taken to be a state in which the individual point charges are very well separated ("are at infinite separation") and are at rest. :§25-1 The electrostatic potential energy of the system (UE), relative to this zero, is equal to the total work W that must be done by a hypothetical external agent in order to bring the charges slowly, one by one, from infinite separation to the desired system configuration:

In this process the external agent is deemed to provide or absorb any relevant work, and the point charge being slowly moved gains no kinetic energy.

Sometimes people refer to the potential energy of a charge in an electrostatic field. This actually refers to the potential energy of the system containing the charge and the other charges that created the electrostatic field.:§25-1

To calculate the work required to bring a point charge into the vicinity of other (stationary) point charges, it is sufficient to know only (a) the total field generated by the other charges and (b) the charge of the point charge being moved. The field due to the charge being moved and the values of the other charges do not need to be known. Nonetheless, in many circumstances it is mathematically easier to add up all the pairwise potential energies (as below).

It is important to understand that electrostatics is a 18th-19th-century theory of hypothetical entities called "point charges". Electrostatics is categorically not a complete theory of the charged physical particles that make up the physical world, and are subject to the Heisenberg uncertainty principle and other laws of quantum mechanics.

This text uses material from Wikipedia, licensed under CC BY-SA