Sometimes when designing in HelioScope, modules will not appear in the final report. This is because the total number of modules is not evenly divisible by the string length, but this situation can occur for a number of potential reasons
Module Count not divisible by string length
When setting a single string length in HelioScope, it is important to check whether your total number of modules is evenly divisible by your string length. In this example, we have 150 modules in our design.
When setting our string length, we want to make sure that our total number of modules (150 in this case) is divisible by the string length. Let's say that we set our string length for this design to 16 to 16.
In this case, we're losing 6 modules at the bottom of the array, because 150/16 = 9.375. We have 9 strings of 16, but the additional modules are not enough to create another string of 16, and they will be removed in the final report.
To deal with this situation, we recommend either:
- Adding/removing modules to reach a total evenly divisible by your string length. You can determine which modules aren't strung by looking at the bottom of the array and seeing which don't have a green string connected to them.
- Editing the string length of your inverter so all the modules will fit. In the case of this array, 15 to 15 would work as a string range and give us 10 strings of 15 modules.
- Selecting a different inverter
Total modules not divisible by string range
Occasionally, when designing in HelioScope, the suggested stringing range for an inverter is not going to be able to string all the modules in a design. This happens most often in residential systems when using string inverters but can occur in commercial designs as well.
In the example above, there are a total of 25 modules in our design. However, the inverter that we have selected has an automatic stringing range of 9-11 modules. There is no way to divide out 25 modules into groups of 9, 10, or 11 modules, and 3 modules end up not strung. By default, HelioScope is going to try to string as many modules as possible, so we have two strings of 11 modules in this case.
To avoid this issue, we recommend setting your stringing range by clicking the blue set manually text at the bottom of the Wiring Zone.
Why won't the program string the different MPPs in my design?
Occasionally we will get users asking why HelioScope is not splitting their strings to different MPPS, and is only stringing a different string length. At the moment, HelioScope automatically splits strings to different MPPS if the user has a stringing range set (for example 11 to 12). However, there is an additional power limit of a 70%-30% split in HelioScope. That means that the difference in power between MPPS cannot be greater than 70% on one side, and 30% on the other. For instance, if the user wanted to have 4 strings of 11 modules and 1 string of 12 modules, that would violate the power split limit and the automatic stringing would not allow it.