SMA SUNNY WEBBOX - Manual (Page 73)

SMA Solar Technology AG 13 Glossary
User Manual SPortal-WB-CLCON-BA-en-25 73
13 Glossary
Azimuth angle
The azimuth angle indicates by how many degrees the module surface deviates from the compass
point due south. In the southern hemisphere, it indicates the deviation from due north. If the module
surfaces are facing due south, the azimuth angle is 0°.
Generator capacity
The generator capacity is the maximum power of the PV modules that are connected to one inverter.
kWp
See peak power
Nominal power (kWp)
See peak power
Peak power (kWp)
The peak power is the maximum power output calculated for a PV module under STC (Standard Test
Conditions).
The peak power is measured in watt peak (Wp), kilowatt-peak (kWp), or megawatt-peak (MWp).
Peak power is also called nominal power.
STC: standard test conditions in the laboratory under which the electrical characteristics of a PV
module are measured. This enables the comparison of different PV modules. The PV modules are
subjected to vertical irradiation of 1,000 W/m
2
, an ambient temperature of 25°C, and a wind speed
of 1 m/s. The electrical characteristics are then measured. The test conditions are designed to
correspond to the ideal ambient conditions for operation of an installed PV module.
Plant power in kWp
The plant power in kWp (kilowatt peak) is the maximum possible plant power. The plant power in
kWp is also known as the nominal power of the plant.
The peak power of a PV plant is the sum of the peak powers of all PV modules installed (see peak
power of a PV module). The peak power of a PV plant is used to compare the plant yield and plant
costs with other PV plants, for example. The peak power of a PV plant is often referred to as
"plant power (kWp)".
An installed plant can rarely achieve peak power because it is not installed in laboratory conditions.
Predicted annual yield (kWh)
The predicted annual yield of a plant is calculated using the specific annual yield (kWh/kWp) at the
plant location and the plant power in kWp (also known as nominal power).
You can obtain the specific annual yield for your PV plant location from irradiation maps.
Specific annual yield (kWh/kWp) x nominal power (kWp) = predicted annual yield (kWh)
Example: Calculation of the predicted annual yield
The specific annual yield at a PV plant location is approximately 900 kWh/kWp. The nominal
power of the PV plant is 4.8 kWp.
Predicted annual yield = 900 kWh/kWp x 4.8 kWp = 4,320 kWh