TNERC Proposes Draft Banking Rules for Green Power Open Access

Tamil Nadu Electricity Regulatory Commission (TNERC) draft Terms and Conditions for Green Energy Open Access Regulations, 2025, aims to enable renewable energy use through the Intra-State Transmission System (InSTS). It also sets the methodology for Open Access Charges and Banking Charges for Green Energy Open Access customers.

The TNERC draft sets banking charges in kind at 8% of the energy banked and permits banking of green energy only on a billing cycle basis for the Open Access consumer. Banked energy must be utilized within the same billing cycle.

In the case of Wind Energy Generators commissioned on or before 31 March 2018 under normal or REC schemes, a banking period of 12 months—from 1 April to 31 March of the succeeding year—would continue to be permitted, along with the applicable banking charges as decided in previous tariff orders (i.e., 14% in kind).

The draft also streamlines the open access process and implements a single-window system nationwide. It provides non-discriminatory open access for renewable energy through InSTS and/or the distribution system, including systems linked to interstate transmission.

It includes an energy accounting provision to be carried out in 15-minute time blocks for Open Access energy accounting purposes for all RE generators, irrespective of the date of commissioning. Any surplus energy after adjustment in the respective 15-minute block would be considered as banked energy, along with the banking charges.

Energy Accounting and Billing

For excess consumption over and above the actual injection of energy will be charged under the draft at the tariff applicable to the consumer, subject to the terms and conditions of supply. Banking and drawal shall be allowed throughout the billing cycle.

Provided that banked energy generated during normal-hour blocks can be adjusted against normal-hour consumption. The draft allows the banked energy generated during night/off-peak hour blocks to be adjusted against night/off-peak consumption, and banked energy generated during peak-hour blocks can be adjusted against consumption in any block period.

Categorization of Green Energy Open Access

The Green Energy Open Access customers are classified into the following categories based on the duration of use of the intra-State transmission and/or distribution system:

• Long-term Green Energy Open Access allows the use of intra-State transmission system and/or distribution system for a period exceeding 12 years but not exceeding 25 years.

• Medium-term Green Energy Open Access gives the right to use the intra-State transmission system and/or distribution system for a period exceeding three months but not exceeding three years.

• Short-term Green Energy Open Access means open access for a period up to one month at a time.

On the expiry of the granted short-term Green Open Access, if the consumer/customer desires to avail of short-term Green Energy Open Access for a further period, they are required to submit a fresh application. In such a case, priority would be fixed based on the date of such an application.