SMA Webconnect Systems in SUNNY PORTAL - Manual (Page 65)

SMA Solar Technology AG 12 Glossary
User Manual SPortalWebcon-BA-en-13 65
Specific system yield (kWh/kWp)
The specific system yield is a key figure that describes the efficiency of a PV system, regardless of its
size. The specific system yield is dependent on the irradiation at the location, the ambient temperature,
shading, tilt and azimuth angle of the PV modules, and the module and inverter power.
You can assess the efficiency of your PV system by comparing the specific system yield of your
PV system with the specific annual yield for the PV system location.
The specific system yield is calculated from the actual measured energy yield (kWh) of a PV system
for a specific period (e.g. one year or one month) divided by the peak power (kWp) of the PV system.
Tilt angle
The tilt angle indicates by how many degrees the tilt of the module surface deviates from the
horizontal.
Example: calculation of the specific system yield for one year
Your PV system consists of 40 PV modules, each with a peak power of 120 Wp (watt peak) as per
manufacturer specification. Hence, your PV system has a peak power of
40 x 120 Wp = 4,800 Wp = 4.8 kWp.
To calculate the specific system yield of your PV system for the year 2011, for example, you will
need the actual (measured) energy yield of your PV system for 2011, e.g. 3,200 kWh. You can
now calculate the specific system yield of your PV system for the year 2011: 3,200 kWh divided
by 4.8 kWp = 666 kWh/kWp in 2011.