Glossary of Wind Turbine & Wind Energy Terms

Glossary

Term Definition
Anemometer

A device that measures wind speeds.

Commercial-scale wind project

Wind projects larger than 100 kW.

Community Wind

An approach to wind energy development that emphasizes local ownership, involvement, and benefits.

Distributed generation

Small-scale power generation technology that is providing electricity for on-site (or nearby) use.

Distribution lines

Low voltage power lines used to distribute electricity over relatively short distances from a power generation facility or substations to consumers.

Electric Grid

A system of transmission and distribution lines connecting synchronized power providers and consumers. Interconnects and facilitates the distribution of electricity to consumers.

Electric Utility

An entity that owns or operates facilities for the generation, transmission, distribution, or sales of electric energy to the public. Usually operates with some form of legal monopoly over the electric services in the geographic area.

Federal Energy Regulatory Commission

An independent regulatory agency within the U.S. Department of Energy having jurisdiction over, among other things, interstate electricity sales and wholesale electricity rates. (Also labeled as FERC)

FERC

An independent regulatory agency within the U.S. Department of Energy having jurisdiction over, among other things, interstate electricity sales and wholesale electricity rates. (also Federal Energy Regulatory Commission )

Green Credits

Used in many states as a tradable renewable energy credit system to enable electric suppliers to meet renewable energy portfolio standards.

Independent power producer

An entity that generates electricity, but is not an electric utility.

Independent system operator

An entity organized by the electric industry to control and administer non-discriminatory access to electric transmission in a region or across several electric systems. (Also described as an ISO)

Interconnection

The physical and electrical interface between a power generator (like a wind turbine) and electric distribution or transmission lines.

Inverter

Electronic device that allows direct current to be converted to alternating current and appropriate voltage, phase and frequency to feed into the utility grid.

ISO

see Independent System operator.

Kilowatt hour

The basic unit of measurement upon which the price of electricity is based. Customers pay per kWh of electricity used. One kWh is equal to 1 kilowatt (1,000 watts) of power used for 1 hour. (Also kWh)

Megawatt

A unit of electrical power equal to 1 million watts or 1,000 kilowatts. (also, MW)

Meteorological power agreement

A contract through which a landowner agrees to allow a wind developer to install wind testing equipment on their land. (also a “MET” tower agreement)

Net excess generation

The amount of electricity produced by a wind turbine constructed to meet on-site energy needs that exceed the farm’s or households immediate demands. Usually calculated on a monthly basis.

Net metering

A method of measuring, on a single electric meter, the amount of electricity consumed from the electric grid and the amount of electricity produced on site and put onto the grid. Net metering allows an electric consumer to accumulate credit for net excess generation that flows back onto the grid.

Parallel generation

Electricity generated on the customer’s side of the electric meter. Sometimes called co-generation.

Power Purchase Agreement

A contract though which a power purchaser (like a utility) agrees to buy electricity from a power generation facility (like a wind project) (Often called a PPA)

Production tax credit

A government incentive for wind energy development that reduces income tax liability based on the amount of renewable energy generation. (Often called a PTC)

PTC

Production Tax Credit: A government incentive for wind energy development that reduces income tax liability based on the amount of renewable energy generation.

Public utilities commission

Sometimes called a Public Service Commission, This is a state’s energy regulatory agency, typically having jurisdiction over, among other things, retail electricity sales to customers and on site power generation projects. (Often called a PUC, or PSC)

Public Utility Regulatory Policies Act

or PURPA, this is a federal statute that, among other things, ensures a market for the electricity produced by small renewable energy generators (called qualifying facilities).

PUC

Public utilities commission: A state’s energy regulatory agency, typically having jurisdiction over, among other things, retail electricity sales to customers and on site power generation projects.

PURPA

Public Utility Regulatory Policies Act : A federal statute that, among other things, ensures a market for the electricity produced by small renewable energy generators (called qualifying facilities).

Qualifying facility

renewable energy generator, as defined by the Public Utility Regulatory Policies Act, with a nameplate capacity of no more than 80 MW.

Rated power

The amount of electricity a generator is expected to produce when operating at maximum performance. If a wind turbine has a rated power of 1,000 kW, then that wind turbine is expected to produce 1,000 kW of energy per hour of operation, when running at its maximum performance.

Renewable energy credit

The environmental attributes of electricity generated from renewable sources, like wind, that are tracked or sold separately from the electricity itself. (Often called a REC)

rotors

Wind turbine blades, using lift to capture the wind’s energy, and hub.

Small-scale wind project.

Definitions vary, but for the purposes of this guide, wind projects of 100 kW and smaller are small scale.

Total System Height

The height from ground level to the tip of the rotor at its highest point.

Tower Height

The height above grade of the fixed portion of the wind turbine tower, excluding the wind turbine and rotor.

Transmission

The transfer of electrical power from one place to another at high voltages.

Transmission lines

High-voltage power lines used to move electricity over relatively long distances from a power generation facility to a substation or other distribution point.

Wind Turbine

A system that converts energy in the wind to electrical energy comprised of a rotor, generator and tower.