Definitions

AC: alternating current

AEP: annual energy production. An estimate of the total energy production of a wind turbine during a one (1) year period as calculated by applying the measured power curve to a Rayleigh frequency distribution at a specified hub height annual average wind speed, assuming 100% availability.

AWEA: American Wind Energy Association

AWEA Rated Power: The wind turbine’s power output at 11 m/s (24.6 mph) per the power curve from IEC 61400-12-1, except as modified in Section II of the AWEA Standard.

AWEA Rated Annual Energy: The calculated total energy that would be produced during a one-year period at an average wind speed of 5 m/s (11.2 mph), assuming a Rayleigh wind speed distribution, 100% availability, and the power curve derived from IEC 61400-12-1 (sea level normalized), except as modified in Section II of the AWEA Standard.

AWEA Rated Sound Level: The sound level that will not be exceeded 95% of the time, assuming an average wind speed of 5 m/s (11.2 mph), a Rayleigh wind speed distribution, 100% availability, and an observer location 60 m (~ 200 ft) from the rotor center, calculated from IEC 61400-11 test results, except as modified in Section III of the AWEA Standard.  Appendix A of the AWEA Standard contains guidance on obtaining sound levels for different observer locations and background sound levels.

AWEA Standard: AWEA Small Wind Turbine Performance and Safety Standard (AWEA Standard 9.1 – 2009). Incorporates, in part, the IEC 61400 series of Standards relevant to small wind turbines with regard to Power Performance (IEC Standard 61400-12-1), Acoustic Noise (IEC Standard 61400-11), and Design Requirements (IEC Standard 61400-2).

BWEA: British Wind Energy Association

BWEA Standard: BWEA Small Wind Turbine Performance and Safety Standard. Incorporates, in part, the IEC 61400 series of Standards relevant to small wind turbines with regard to Power Performance (IEC Standard 61400-12-1), Acoustic Noise (IEC Standard 61400-11), and Design Requirements (IEC Standard 61400-2).

Cp: power coefficient

Cut-in Wind Speed: The first wind speed bin in the averaged power curve that is positive.

Cut-out Wind Speed: The wind speed above which, due to control function, the wind turbine will have no power output.

ed: edition

HAWT: horizontal axis wind turbine

IEC: International Electrotechnical Commission

ISO: International Organization for Standardization

JSWTA Standard: Japanese Small Wind Turbine Association Small Wind Turbine Performance and Safety Standard (JSWTA 0001).  Incorporates, in part, the IEC 61400 series of Standards relevant to SWTs with regard to Power Performance (IEC Standard 61400-12-1).  Acoustic Noise (IEC Standard 61400-11), and Design Requirements (IEC Standard 61400-2).

Maximum Power: The maximum one-minute average power output a wind turbine in normal steady-state operation will produce (peak instantaneous power output can be higher).

Maximum Voltage: The maximum instantaneous voltage the wind turbine will produce in operation including open circuit conditions.

Maximum Current(s): The maximum instantaneous current(s) the wind turbine will produce on each side of the system’s control or power conversion electronics.

MCS: Microgeneration Certification Scheme

OTF: operational time fraction

Overspeed Control: The action of a control system, or part of such system, which prevents excessive rotor speed.

Power Form: Physical characteristics which describe the form in which power produced by the turbine is made deliverable to the load.

Qualified Testing Organization: A testing organization that is qualified under SWCC’s Certification Policy and applicable SWCC requirements to perform wind turbine testing for the purpose of certification. In order to receive SWCC Qualified Testing Organization status, the organization must demonstrate compliance with all relevant requirements of the AWEA Standard and ISO/IEC Standard 17025.

Rotor Swept Area: Projected area perpendicular to the wind direction swept by the wind turbine rotor in normal operation (un-furled position). If the rotor is ducted, the area inscribed by the ducting shall be included.

SWT: small wind turbine

Turbulence Intensity: The standard deviation of wind speed divided by the mean wind speed based on 1-minute averaged data that is sampled at 1 Hz.

VAWT: vertical axis wind turbine