SMA SB 240-US-10 - Manual (Page 73)

SMA America, LLC
12 Glossary
User Manual SPortalMGate-US-BA-en-10 73
Specific Annual Yield (kWh/kWp)
The specific annual yield is a calculated average value of specific plant yield values of different
PV plants for a location. You can obtain the specific annual yield for your PV plant location from
irradiation maps. You can assess the efficiency of your PV plant by comparing the specific plant yield
of your PV plant with the specific annual yield for your PV plant location.
Specific Plant Yield (kWh/kWp)
The specific plant yield is a key figure that describes the efficiency of a PV plant, regardless of its size.
The specific plant yield is dependent on the irradiation at the location, the ambient temperature,
shading, tilt and azimuth angle of the PV modules, and the power of the PV modules and inverters.
You can assess the efficiency of your PV plant by comparing the specific plant yield of your PV plant
with the specific annual yield for your PV plant location.
The specific plant yield is calculated from the actual measured energy yield (kWh) of a PV plant for
a specific period (e.g. a year or a month) divided by the peak power (kWp) of the PV plant.
Tilt Angle
The tilt angle indicates by how many degrees the tilt of the the module surface deviates from the
horizontal.
Example: calculation of the specific plant yield for a year
Your PV plant consists of 40 PV modules, each with a peak power of 120 Wp (watt peak)
according to the manufacturer specification. Thus, your PV plant has a peak power of
40 x 120 Wp = 4,800 Wp = 4.8 kWp.
To calculate the specific plant yield of your PV plant for the year 2011, for example, you will need
the actual (measured) energy yield of your PV plant for 2011, e.g. 3,200 kWh. You can now
calculate the specific plant yield of your PV plant for the year 2011: 3,200 kWh divided by
4.8 kWp = 666 kWh/kWp in 2011.