The regular periodic arrangement of atoms or molecules in a crystal of semiconductor material.

The change in heat content that occurs with a change in phase and without change in temperature.

Site planning that accounts for natural solar heating and cooling processes and their relationship to building shape, orientation, and siting.

The thermodynamic cycle that is an ideal standard for comparing performance of heat-engines, steam power plants, steam turbines, and heat pump systems that use a condensable vapor as the working fluid; efficiency is measured as work done divided by sensib ...

An electrical inverter that inverts direct current electricity to alternating current electricity, and that uses another alternating current source, such as an electric power transmission and distribution network (grid), for voltage and frequency referenc ...

The alignment of a building along a given axis to face a specific geographical direction. The alignment of a solar collector, in number of degrees east or west of true south.

A graph representing the relationship between the power available from the wind and the wind speed. The power from the wind increases proportionally with the cube of the wind speed.

A wood-burning appliance for space and/or water heating and/or cooking.

A mathematical representation of the frequency or ratio that specific wind speeds occur within a specified time interval.

Alternating current is carried by conductors and a ground to residential, commercial, or industrial consumers. The waveform of the phase power appears as a single continuous sine wave at the system frequency whose amplitude is the rated voltage of the pow ...

A company or individual that is not directly regulated as a utility. These entities produce power for their own use and/or sell it to regulated utilities.

A hydropower plant that is operated at maximum allowable capacity for part of the day and is either shut down for the remainder of the time or operated at minimal capacity level.

A device where sunlight concentrated onto a absorber heats it to a high temperature, and the thermal radiation emitted by the absorber is used as the energy source for a photovoltaic cell that is designed to maximize conversion efficiency at the wavelengt ...

The process of the absorption of heat from one location and its transfer to another for rejection or recuperation.

A wall to prevent the spread of fire; usually made of non-combustible material.

States that energy cannot be created or destroyed, but only changed from one form to another. First Law efficiency measures the fraction of energy supplied to a device or process that it delivers in its output. Also called the law of conservation of energ ...

A unit of pressure for a fluid, commonly used in water pumping and hydropower to express height a pump must lift water, or the distance water falls. Total head accounts for friction head losses, etc.

A WECS designed to produce electricity.

In reference to a wind energy conversion system, the area of a turbine blade surface that first comes into contact with the wind.

In alternating current, the current goes from zero potential or voltage to a maximum in one direction, back to zero, and then to a maximum potential or voltage in the other direction. The number of complete cycles per second determines the current frequen ...