An eQUEST Photovoltaic question paraphrased from the mailbag

"I created a PV system in eQUEST as shown step by step in your online tutorial. However, in my test file, I can't seem to change the total energy savings. The first problem is that, even if I change the size/area of the PV panel, I can't seem to increase the total kilowatt capacity of the PV in the PS-H report.  Additionally, if I increase the number of PV units, I also show no additional savings. How do I increase the PV savings?"

Answer:

Great question and you are on the right track. There's a few notable points. 

The capacity for a photovoltaic in eQUEST would seemingly come from the size of the PV panel. However, that is not the case when it is determined in eQUEST. The KW capacity of a PV is determined from the user input of Max Power Voltage, Vmp and Max Power Current, Imp. 

You can see this yourself if you edit the PV as shown here.

These two inputs alone will change the KW capacity of the PV in a typical setup. Notwithstanding, you should follow the design and manufacturer inputs as closely as possible, because the total performance of the PV array will vary greatly based on the other parameters - especially because the output of the PV array is a result of temperature, solar intensity, solar angles, electrical setup, and many more variables

But in a matter of simply speaking, the peak capacity of a PV generator results from the PV unit Max current and voltage (since volts times amps = Watts).

Then, as you noted, the total number of PV units will increase your total power. This of course, in simple math, should simply be additive in that if you install 10 PV panels that are 500 watts each, you should have 5 KW of capacity. However, the electrical setup and the inverters are also important. 

In the case of the model you had sent us, it appears that you had set up the majority of your PV panels in series. As a rough estimate, at 60 volts each, 50 panels in series, will result in 3000 volts

By default, your inverter is limited to operate up to 400 volts. If you continue adding PV's in series, you will see no improvement. Instead you add your PV units in parallel (Which is likely the design), at that point you will see a change of total electric consumption in your BEPS report.

Note that the inverter capacity (assuming just 1 inverter) should be greater than your entire PV capacity, or your inverter will become a limiting factor. 

You can alternatively change the maximum tracking voltage, but it is unlikely that will be true to the design.

If you want to learn how to setup PV in eQUEST, you can learn how to implement it in our step by step tutorials:

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