The Tamil Nadu Solar Energy Policy 2019, set an overall solar energy target of 9,000 MW. 40 percent of this target, or 3,600 MW, is meant to be met from the consumer category (behind-the-meter) or rooftop solar segment. As of 31st March 2021, a cumulative rooftop solar capacity of 325 MW has been recorded in the state, this represents only 9 percent of the state’s rooftop solar target.

In 2021 the Tamil Nadu Electricity Regulatory Commission (TNERC) passed its General Tariff Order for Grid Interactive PV Solar Energy Generating Systems. The objective of the order  was to “accelerate the deployment of consumer category solar energy systems and to meet the State’s target of 3,600 MW by 2023”.

The 2021 Tariff Order permitted the participation of HT consumers under the net feed-in tariff mechanisms, introduced the choice of domestic consumers to avail either the net metering or the net feed-in mechanism, allowed solar gross metering for solar systems of 150 to 999 kW capacity and set, for the first time, capacity varying solar feed-in tariffs based on a levelized cost of energy (LCOE) calculation.

Additionally, TNERC introduced network charges, to help DISCOM to better recover its fixed costs. Networks charges are levied on the gross generation of solar energy and therefore apply to both the portion of the solar energy that is self-consumed and the portion that is exported to the grid. The network charges for the domestic consumer category have been determined 0.25 INR/kWh.

The objective of this briefing note is to assess whether the recent General Tariff Order for Grid Interactive PV Solar Energy Generating Systems (GISS) by the Tamil Nadu Electricity Regulatory Commission has improved the financial attractiveness of rooftop solar energy for the domestic consumer segment in the state.