MNRE advises 10% DC capacity tolerance for PM Surya Ghar rooftop solar
The Ministry of New and Renewable Energy (MNRE) has advised Distribution Companies (DISCOMs) and Electricity Departments to allow up to 10% tolerance in the DC capacity of rooftop solar systems while processing net metering applications under the PM Surya Ghar: Muft Bijli Yojana (PMSG: MBY).
The advisory, issued in March 2026, addresses cases where net metering applications were being returned because the installed DC capacity of solar modules marginally exceeded the applied system capacity or permitted inverter AC capacity. MNRE has clarified that the tolerance can be allowed provided the inverter’s AC capacity does not exceed the sanctioned load or the maximum inverter capacity permitted under applicable regulations.
Capacity mismatch
The clarification follows representations from vendors and vendor associations over delays arising from minor differences between the aggregate DC capacity of solar modules and the AC capacity of inverters. Applications involving configurations such as 3.24 kW DC of solar modules paired with a 3.0 kW inverter were reportedly being rejected, delaying commissioning of rooftop solar systems.
MNRE noted that solar modules are commercially available in different wattages, making it difficult in some cases to precisely match their aggregate DC capacity with the sanctioned load or permissible inverter AC capacity prescribed under prevailing regulations. The ministry has therefore recommended allowing DC capacity of up to 10% above the applied system capacity while retaining the applicable limit on inverter AC capacity.
For a 5 kW system, MNRE illustrated that nine modules providing 4.86 kW DC or 10 modules providing 5.40 kW DC can be accepted under the tolerance, while the inverter must remain restricted to 5 kW AC.
Similarly, for a 10 kW system, 18 modules providing 9.72 kW DC or 19 modules providing 10.26 kW DC fall within the permitted tolerance, provided the inverter AC capacity does not exceed 10 kW.
The advisory is intended to address practical module-sizing mismatches in net metering applications under PMSG: MBY and reduce commissioning delays arising solely from small differences between installed module DC capacity and the applicable system capacity.
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