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How to define the size of your PV plant

Got some project size specifications you need to abide by? You came to the right place!


Whether it's installing as much power as possible within a designated area, trying to reach a target capacity, or having to abide by certain delivery point limitations, pvDesign can do all three!

Maximum capacity

So, you have just decided that you want to install as much power as possible inside your defined plot area. Well, say no more! In pvDesign's Layout tab, you'll simply have to select the Maximum Capacity option as shown in the image below.

With the maximum capacity option selected, all you'll need to do is choose your target DC/AC ratio. In the scenario, we will set the DC/AC ratio to 1.2.

At any stage of the design process, the top bar will allow us to check how much maximum power can be installed in our PV plant.

Specific Capacity

What if I want to install a specific power? Simply select the Specific Capacity option in the Layout tab.

Using the design from before, we define our PV plant to have 50 inverters, thus obtaining 85.75 MWac. 

To ensure that we reach the exact specific power that we want, we will first need to calculate the DC/AC Ratio associated with our peak power. If, for example, we want 99.984 MWdc, a DC/AC ratio of 1,166 must be included as a power requirement.

Secondary Inverter and configuration of power stations

In addition to working with the primary inverter, we can enable a secondary inverter in the Equipment tab. The secondary inverter can be defined for both Maximum Capacity and Specific Capacity

In the Inverters per Power Station (PS) section within the Equipment tab, we can define the number of primary and secondary inverters to install for each power station.


This will apply to most power stations, however, if the number of total inverters is not a multiple of the number of inverters defined in a power station, smaller power stations will be defined. These can be seen in detail in the documentation once the design has been generated.

If we select the Specific Capacity option on the Layout tab, we can define an AC power based on the power of the 2 inverters and the number of inverters.

Power limitation at the delivery point

What if I want to define a power limitation in my PV plant instead of reducing the installed capacity? In pvDesign, you can set a power limitation at the delivery point, by enabling the option in the Layout tab (Power Requirements) and specifying the active power limit.

This way, pvDesign will design your PV plant based on your inputs (the power limitation option is available for both Maximum Capacity and Specific Capacity), and the energy yield results will take into consideration this power limitation. This means that if our plant can generate energy at a higher power than this limit, pvDesign will cap the plant's energy generation.

For any other questions or more information regarding this topic, you can contact us at: support@ratedpower.com