Integrating distributed energy generation into the grid is a challenge for grid operators around the world. In 2012, Tamil Nadu limited the amount of SPV grid penetration on the low tension side of the distribution transformer (DT) to 30% of the DT rated capacity. Auroville Consulting conducted a study of two transformers in Auroville, to understand the technical implications, if any, of approaching the grid penetration limit.

Measurements indicate that the import of active energy from the grid reduced in proportion to the SPV generation. The study also showed that line voltages across the low-tension terminals of the distribution transformer increases at the most by 1% to 1.2% (monthly average) when SPV is turned on, with the phase to neutral voltage remaining within the acceptable range of 230V ± 8%.

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