Configuring Strings

A string describes a group of series-connected PV modules. Normally, a system is made up of multiple strings. Each string has specific properties, such as deviation to south (azimuth) or the roof tilt angle.

The configuration of the strings is of fundamental importance for the correct calculation of the PV forecast and thus an important prerequisite for load planning as well as the optimization of self-consumption and the self-sufficiency quota.

The following table explains the properties of a string, partly with examples for settings:

String properties

Explanation

Designation

Name of the string, e.g. String A or East side

Manufacturer

PV module manufacturer

Module type

Depending on the selected manufacturer, different module types are displayed in the drop‑down list.

Module power1)

These values are applied automatically from the module database once you have selected the module type. You can change the values using or the arrow keys on the keyboard.

Module surface

Efficiency

Number of modules1)

Number of modules forming the string

Azimuth

The azimuth angle indicates by how many degrees the module surfaces deviate from a southern orientation. The azimuth is required for the exact calculation of the PV yield prognoses and can be determined with the help of the Sunny Design evaluation, for example.

  • In the text field, enter the number of degrees by which the module surfaces deviate from a southern orientation. Enter a negative value (e.g. −20) for a deviation to the east and a positive value (e.g. 20) for a deviation to the west.

  • If the module surfaces track the sun automatically, activate the checkbox Tracking.

Tilt angle

The tilt angle indicates by how many degrees the module surfaces deviate from the horizontal. In some systems, the module surfaces are optimally aligned according to the latitude. In Germany, the optimum orientation is 30 degrees from the horizontal.

  • In the text field, enter the number of degrees by which the module surfaces deviate from the horizontal.

  • If the module surfaces are optimally aligned according to the latitude, activate the checkbox Optimized.

Description

Optional, e.g. String A - Orientation to the east

1) Relevant for calculation of the nominal system power

Creating New String

Requirement:

  • The system must contain at least 1 inverter.

  1. Under Configuration > PV system properties select the tab String configuration and then Add string.
  2. In the Inverter line, from the drop-down list select an inverter to which the string is to be assigned ( > Device Overview Tab).
    You can register the connected strings for all inverters. To initially register the same configuration for all devices, select Apply for all inverters when adding a string.
  3. Enter the string properties (compare table).
  4. Click on [Accept].
  5. Click on [Save].

Accept existing string and edit

Requirement:

  • At least 1 string must already be configured in your system.

Procedure:

  1. Select 1 string or inverter shown in the table on the tab String configuration.
  2. In the line of the selected string and the column Copy, select .
  3. In the column Edit of the copied string line, select .
  4. The menu for setting the string opens.
  5. Enter the string properties:
  6. Click on [Save].
    Changing or Deleting the System Image
    Changing Operator Data