DC/AC Ratio: Choosing the Right Size Solar Inverter
The DC-to-AC ratio, also known as the Inverter Loading Ratio (ILR), is the ratio of the installed DC capacity of your solar panels to the AC power rating of your inverter.
Because the PV array rarely produces power to its STC capacity, it is common practice and often economically advantageous to size the inverter to be less than the PV array. This ratio of PV to inverter power is measured as the DC/AC ratio. A healthy design will typically have a DC/AC ratio of 1.25.
DC/AC ratio, also called inverter loading ratio (ILR), is the array's STC power divided by the inverter's AC nameplate power. ILR = P DC, STC / P AC, rated. A higher ILR feeds more energy during long shoulder hours and in winter, at the cost of some midday clipping on clear, cool days.
The DC and AC Ratio (also called Inverter Loading Ratio – ILR) is the ratio between the total installed DC capacity of solar panels and the AC capacity of the inverter. For example, if a solar plant has 10 MWp DC capacity and an 8 MW AC inverter, the ratio is 1.25. Q2. Why is DC and AC Ratio important in solar projects?
To calculate the DC/AC ratio for your solar system, use this simple formula: Total Solar Panel Capacity (DC Watts) ÷ Inverter Capacity (AC Watts) DC/AC Ratio = 8000 ÷ 7000 = 1.14 This calculation helps ensure your inverter can handle the system's maximum DC power efficiently.
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