About the Evacuation Voltage Optimizer

Evacuation voltage selection determines the appropriate grid voltage level for connecting a solar plant — matching the plant's capacity to the nearest substation's available voltage level and ensuring that the grid can handle the plant's full output without overloading.

How to calculate it

1. 1Match capacity to voltage level: up to 1 MW → 11 kV; 1–50 MW → 33 kV; 50–400 MW → 132/220 kV; > 400 MW → 400/765 kV.
2. 2Check substation capacity: available import capacity at the target substation must be ≥ plant output × 1.15.
3. 3Check line capacity: the 11 kV or 33 kV line from plant to substation must be rated for the plant's fault current; line length affects voltage regulation.
4. 4For net metering (< 1 MW rooftop): 415 V LT or 11 kV HT connection depending on plant size and DISCOM preference.
5. 5For captive/group captive plants: evacuation voltage is determined by the captive consumer's existing connection voltage.

Worked example

A 5 MWp ground-mount plant in Rajasthan: 33 kV is the correct evacuation voltage. The nearest 33 kV substation is 4 km away. DISCOM capacity check shows 3 MW available on the feeder — insufficient for 4 MW export. Options: (1) upgrade the substation feeder, (2) connect to the 132 kV substation 8 km away.

What you can calculate

• Voltage class
• CEA 2023
• Line loss <3%
• Line current

Frequently asked questions