International Electrotechnical Commission
Glossary

ENyield 
(Unit: J kW–1. Usually expressed as kWh kW–1 over any convenient unit of time. It is commonly calculated over a day, which then gives a unit of h d–1.)

duration that a PV device would need to operate at its rated power in order to generate the same amount of energy that it actually did generate

NOTE 1 A yield indicates actual device operation relative to its rated capacity

NOTE 2 A yield is calculated from the ratio of the energy generated to the rated device power

NOTE 3 Since yields can be calculated over any time period, the time interval in which they are being referenced is always specified as per IEC 61724

a) array yield

(Symbol: YA)

PV array energy generated per unit of rated PV array capacity

b) final annual yield

total PV energy delivered to the load during one year per unit of rated PV array capacity

c) final system yield

(Symbol: Yf)

portion of the net energy generated by the electric generating system that was supplied by the PV array per unit of rated array capacity

d) reference yield

(Symbol: Yr)

duration that the irradiance would need to be at reference irradiance levels to contribute the same incident irradiation as actually occurred

It is calculated from the ratio of the total irradiation to the reference irradiance GI,ref

NOTE 4 If GI,ref = 1 kW m–2 then the irradiation as expressed in kWh m–2 over any period of time is numerically equal to energy as expressed in kWh kW–1 over that same period. Thus Yr would be, in effect, rated sun-hours over that same period


TC/SC:82Terms     Info     Publications
Published in:IEC 61836, ed. 2.0 (2007-12) Terms     Info
Reference number:3.4.96

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