NLC India Ltd. and the State Load Despatch Centre (SLDC) are engaged in a tussle before the Tamil Nadu Electricity Regulatory Commission (TNERC) over the issue of curtailment of renewable energy.
In its petition before the TNERC, NLC said it had installed 1,400 MW capacity of renewable energy (solar and wind) with an investment of nearly ₹6,000 crore and has entered into power purchase agreements with the Tamil Nadu Generation and Distribution Corporation Limited (Tangedco).
The company also said its solar installed capacity accounts for 33.5% of the total solar capacity of Tamil Nadu (4,007 MW). It alleged that the curtailment of solar and wind energy capacity, citing grid security as a reason, has been on the rise since April 2019.
NLC said it had requested the SLDC to avoid back downs, and after repeated requests, the back downs were reduced between November 2019 and March 2020. However, again in April 2020, the company said the SLDC had started issuing frequent back down requests to its solar plants with a capacity of 1,209 MW situated in the southern districts of Tamil Nadu.
The instructions reduced its solar power generation capacity by 25% to 50%, according to the company. NLC said it has lost a quantity of nearly 98.95 million units of renewable energy generation, resulting in revenue loss of ₹34.615 crore from 2018-19 to 2020-2021 (up to September).
The company also said as per the quarterly report of the SLDC, back down instructions had been issued to solar power plants for 217 days for the period from April 2019 to June 2021. In addition, there were 58 more days of back down instructions, taking the total number of days to 275, it alleged.
NLC sought for a direction to the SLDC to stop issuing curtailment instructions to solar and wind plants, except in situations as contemplated in the applicable regulations and as per the power purchase agreement. In its reply, the SLDC said the curtailment was done only for grid security reasons.
It also said the claim by NLC on the quantum of generation loss was not properly put forth since the total generation was not mentioned. SLDC also said 217 days of curtailment pertain only to grid parameters, while the remaining 58 days was due to overloading of auto-transformers.
According to it, in April 2020, the back down instructions were slightly higher due to less demand on account of frequent lockdowns owing to the pandemic.
After hearing both sides, the TNERC noted that the Appellate Tribunal for Electricity had given a clear ruling on the issue of curtailment of renewable energy. Further, it said in a previous order, it had also directed the SLDC to evolve a protocol for curtailment and there was nothing to adjudicate on NLC’s plea. It added that the NLC has to file a separate dispute resolution petition, for seeking commercial relief, if any, such as Deemed Generation.
