TNERC hikes tariff for rooftop solar systems

However, the consumers having battery connected rooftop solar systems would get a 20 per cent higher feed-in tariff under the time-of-the-day (ToD) tariff.

TNERC has fixed solar energy tariffs of Rs 3.61 per unit for rooftop system capacities up to 10 kilowatts, Rs 3.37 per unit for capacities from 11 to 150 kW and Rs 3.10 per unit for 151 to 999 kW capacities.

To incentivise the prosumers to install energy storage for utilisation of stored solar energy, the commission said that the ToD solar feed-in tariff is proposed to be 20 per cent higher than the feed-in tariffs. Under the ToD tariff, the system capacities up to 10 kW is Rs 4.33 per unit, Rs 4.04 per unit (11 to 150 kW) and Rs 3.72 per unit (151 to 999 kW).

According to the tariff order, the domestic consumers are eligible for the net-metering mechanism up to the level of sanctioned load while all the electricity consumers could avail the net feed-in mechanism up to a maximum capacity of 999 kW. Under the gross metering mechanism, only HT consumers are eligible for it and the minimum size of the solar system should be 151 kW and the maximum capacity 999 kW.

Net metering and net billing are two ways to calculate compensation paid to private rooftop solar units that sell their excess private power generation to the grid using a bi-directional meter. In the net metering arrangement, the producer-consumer (prosumer) can subtract the energy they sell (in terms of units) to the grid from the number of units that they buy. The difference between these two figures is billed according to standard slab rates. Under the net billing arrangement, the prosumer sells their excess energy to the grid at a standard feed-in tariff while the energy they buy will be charged at slab rates.

Under the gross metering, all the energy generated through the solar system would be sold to the grid at the feed-in tariff.

All the low tension and high tension rooftop consumers have to pay network charges for Tangedco on the total generated units. The commission has fixed the network charges at Rs 0.83 per unit and Rs 1.27 per unit for HT and LT consumers. Domestic consumers would have to pay 20 per cent of network charges up to 10 kW and 75 per cent over 10 kW under the net metering mechanism.