Inverter Loading Ratio (ILR / DC-AC Ratio)
The ratio of installed DC module capacity to AC inverter capacity — deliberately set above 1.0 so the inverter runs near its efficient operating point more of the day.
Why oversizing DC is correct
Modules rarely produce nameplate output. Sizing 1.2 MWp of modules to 1 MW of inverter (ILR 1.2) fills the inverter's efficient band through more hours and raises annual yield, at the cost of clipping a few peak hours in summer.
Where the optimum sits
1.15-1.35 for most Indian plants; higher for storage-coupled or evening-weighted tariffs where clipping is captured in the battery instead of lost. Push past 1.4 on a flat tariff and clipping losses outgrow the gain.
Related terms
Where this applies
Utility-Scale Solar EPC, Battery Energy Storage (BESS)
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