Regulatory bodies must adhere to established tariff orders and ensure procedural fairness in tariff determinations, allowing affected parties the opportunity to be heard.

ORDER :

1. All these Writ Petitions seek identical reliefs and are therefore taken up and disposed of by this common order.

2. The Writ Petitioners are power-generating companies. The subject matter of the dispute relates to the tariff for "startup power” that these companies use intermittently to start their generators. The prayer in these Writ Petitions challenges the instructions issued by the Chief Financial Controller/Revenue (FAC), Tamil Nadu Power Distribution Corporation Limited - the second respondent herein, dated 12.12.2024. These instructions direct all the Superintending Engineers of the organisation to bill all generators utilising startup power under High Tension Tariff-I (a two-part tariff system), as specified in the suo motu Tariff Order No. 6 dated 15.07.2024 (effective from 01.07.2024). The petitioners also challenge the consequential demand notices issued to the individual generating companies. The consequential prayer is to direct the second respondent - Tamil Nadu Power Distribution Corporation Limited (TNPDCL) to refrain from pursuing any recovery actions contrary to the tariff orders issued by the Tamil Nadu Electricity Regulation Commission (TNERC) and pending the determination of the tariff for startup power by the fifth respondent in compliance with the directives of Appellate Tribunal for Electricity (APTEL) in its order dated 08.10.2024 in A.No.396 of 2024.

3. The key facts essential for resolving the issues currently present in these Writ Petitions, in light of certain subsequent developments, are as follows:

3.1. Originally, by a circular dated 07.09.2013, the TNPDCL imposed a two-part tariff system for startup power. Claiming that this was against the tariff order, a batch of Writ Petitions in W.P.Nos.26266 of 2013, etc., were filed, and interim orders were granted on conditions directing that 25 % to 50 % of the charges levied shall be paid by the companies pending the disposal of the Writ Petitions.

3.2. While the Writ Petitions were pending, on 13.03.2014, the open access regulations were notified, repealing the 2005 regulations. Regulation 25 prescribes the charges for startup power supplied by the distribution licensee and imposes restrictions based on usage, limiting it to 42 base units per year. During the pendency of the above Writ Petitions, tariff orders for the years 2014 – 2017 were also issued. Subsequently, this Court considered the aforementioned batch of Writ Petitions and, by an order dated 27.08.2021, laid down the best practices to be followed by the TNPDCL and transferred the Writ Petitions to the TNERC for adjudication.

3.3. On 09.09.2022, the tariff order was issued for the control period of the financial years 2022 – 2023 to 2026 – 2027. While the aforementioned transfer applications in T.A.Nos.13 of 2022 and Batch were pending before the TNERC, the restriction on usage for 42 days per year was relaxed in the tariff order. Furthermore, on 30.06.2023, an order No.6 of 2023 for a suo-motu tariff revision was issued for the financial year 2023 – 2024. Subsequently, on 29.12.2023, the TNERC issued an order categorizing pure generators, such as the petitioners using startup power, under the temporary supply category (HT – V) and fixed energy equated demand charges at 125% of the temporary supply energy charges. These directives were made prospectively applicable from the date of the order. On 15.07.2024, a suo-motu tariff revision order for the financial year 2024-2025 was issued by the TNERC. On 20.08.2024, the TNPDCL issued implementation instructions directing all Superintending Engineers to ensure compliance with the TNERC's order dated 29.12.2023 from the date of the order. The instructions also directed all Superintending Engineers to comply with the 2024 tariff order. The TNPDCL filed an appeal challenging the TNERC’s order dated 29.12.2023, which categorized the pure generator using startup power under the temporary supply category. This appeal was filed as APL. No.290 of 20