A virtual power plant is a cloud-based distributed power plant that aggregates the capacities of heterogeneous distributed energy resources for the purposes of enhancing power generation, as well as trading or selling power on the electricity market.

Virtual net metering also called peer-to-peer is a method of producing power to the grid where sellers can generate their own energy in dwellings, offices and factories, and share it with each other locally.

The very-high-temperature reactor, or high-temperature gas-cooled reactor, is a Generation IV nuclear reactor concept that uses a graphite moderator with a once-through uranium fuel cycle.

Vertical wind shear is a change in wind speed or direction with a change in altitude.

Vertical-axis wind turbines have the main rotor shaft arranged vertically.

Ventilative cooling is the use of natural or mechanical ventilation to cool indoor spaces.

The velocity of an object is the rate of change of its position with respect to a frame of reference, and is a function of time.

Vehicle-to-grid describes a system in which plug-in electric vehicles, such as battery electric vehicles, plug-in hybrids or hydrogen fuel cell electric vehicles, communicate with the power grid to sell demand response services by either returning electricity to the grid or by throttling their charging rate.

Vegetable oil can be used as an alternative fuel in diesel engines and in heating oil burners.

Vector control, also called field-oriented control, is a variable-frequency drive control method in which the stator currents of a three-phase AC or brushless DC electric motor are identified as two orthogonal components that can be visualized with a vector.

A vector (sometimes called a geometric vector or spatial vector) is a geometric object that has magnitude (or length) and direction.

A variable-frequency transformer is used to transmit electricity between two (asynchronous or synchronous) alternating current frequency domains.

A type of motor drive used in electro-mechanical drive systems to control AC motor speed and torque by varying motor input frequency and voltage.

A turbine designed to operate at varying rotational speeds to enable

Variable renewable energy is a renewable energy source that is non-dispatchable due to its fluctuating nature, like wind power and solar power, as opposed to a controllable renewable energy source such as dammed hydroelectricity, or biomass, or a relatively constant source such as geothermal power.

Variable costs are costs that change as the quantity of the good or service that a business produces changes.

Vaporisation of an element or compound is a phase transition from the liquid phase to vapor.

Vapor–liquid equilibrium describes the distribution of a chemical species between the vapor phase and a liquid phase.

In fluid mechanics, pressure head is the height of a liquid column that corresponds to a particular pressure exerted by the liquid column on the base of its container.

Pressure drop is defined as the difference in total pressure between two points of a fluid carrying network.