The Indian Electricity Grid Code (IEGC) 2023, which was notified in July 2023, and effective from October 2023, established comprehensive operational guidelines for the electricity grid in India. It has helped ensure efficient, reliable and secure operation of the national grid. The Central Electricity Regulatory Commission (CERC), from time to time, has issued several orders to provide clarity and remove difficulties for stakeholders in implementing various provisions of the grid code.
Chapter 7 of the IEGC 2023, Scheduling and Despatch code, deals with the procedure for scheduling injection and drawal of power by regional entities and the modalities for the exchange of information, including scheduling for intra-state entities transacting power through the interstate transmission system. While the grid code outlines modalities for scheduling under general network access (GNA and T-GNA), stakeholders have identified challenges, particularly concerning the scheduling of infirm power, that is, the electricity generated during the testing and commissioning phases before a project’s commercial operation date (COD).
The CERC has issued two orders so far, in September and December 2023 respectively, to address these concerns. In order to address the complexities associated with infirm power, the CERC, recently in its third order dated December 22, 2024, provided explicit guidelines on the scheduling of infirm power to minimise system imbalances during the pre-COD phase. The order delineates separate protocols for general sellers such as thermal or hydro generators and renewable energy generating stations (REGSs), including those with energy storage systems.
Order background
Currently, scheduling of infirm power is being carried out, but the modalities of scheduling it need to be explicitly specified through an amendment to the Grid Code, which may take some time. Since scheduling is already being carried out, there is a need to specify the modalities of such scheduling till such time amendments to the Grid Code are carried out for the clarity of stakeholders.
The scheduling of power prior to the COD is required to be considered, keeping in view the following Regulations of the Grid Code: (a) Regulation 19, which allows the interchange of infirm power for a specified period, (b) Regulation 22, which provides for a trial run for a generating station with a minimum capacity for such a trial run and the maximum number of instalments in which the same can be achieved, and (c) Regulation 27, whereby a generating station declares COD for its project where an REGS can declare COD, subject to the fulfilment of conditions as per the power purchase agreements (PPAs), if any.
For general sellers, infirm injection is permitted only after the initial synchronisation with the grid and is limited to a maximum of one year. This period can be extended with a no-objection certificate from the respective regional load despatch centres (RLDCs). Deviations in such cases are settled under the 2024 deviation settlement mechanism (DSM) regulations. In contrast, for REGS, infirm injection is allowed only after a successful trial run. Power scheduling can commence following the issuance of a trial run certificate by the RLDC, with DSM regulations governing any deviation charges.
Trial operation of a REGS for installed capacity of 250 MW or more
Clause 3(a) of Regulation 22 of the Grid Code provides that the trial run of the solar project shall be performed for a minimum capacity, aggregating to 50 MW, and in case the project has a capacity of more than 50 MW, the trial run for the balance capacity shall have to be performed in a maximum of four instalments.
During the public hearing on the draft’s first amendment to the Grid Code as well as during the visit of the officers of the commission to various renewable energy projects in Rajasthan and Karnataka, the renewable energy developers suggested that in the case of projects with higher installed capacity, the restriction on the number of instalments leads to difficulty in achieving a successful trial run in a short span of time and, accordingly, the number of instalments may be reviewed.
To provide greater operational flexibility for developers, especially those with large-scale projects, the CERC has removed the trial run instalment cap for renewable energy projects with an installed capacity of above 250 MW. However, it mandates that each instalment must be at least 50 MW. This adjustment allows developers to better align their testing processes with project-specific requirements, facilitating a more efficient commissioning phase.
Issuance of a certificate for successful trial run
The CERC has also clarified the process for scheduling power generated post-trial operations, but before the COD. The commission has clarified that regardless of any provisions in the PPA, the scheduling of power is permitted only after the issuance of a successful trial run certificate by the RLDC.
Prior to obtaining this certificate, generating stations must seek explicit permission from the RLDC for each instance of infirm power injection, providing comprehensive details of the commissioning activities and their duration. Once the trial run certificate is issued, the generating station is expected to declare COD promptly. If there is a delay in declaring COD post-trial run, the reasons must be documented in writing. In cases where PPAs do not explicitly address the treatment of power post-trial operation, the first right of refusal lies with the identified beneficiaries. If these beneficiaries decline or do not respond in a timely manner, the generator is permitted to sell power in the open market.
Implications
These directives underscore the CERC’s commitment to ensuring a balanced and efficient integration of infirm power into the grid, thereby maintaining grid stability, while accommodating the dynamic nature of power generation during the commissioning phases. By providing clear guidelines and enhancing flexibility, the CERC aims to facilitate smoother operations for generators and stakeholders involved in the power sector.
For project developers, these clarifications offer a structured pathway to manage the complexities associated with the injection of infirm power. The removal of the trial run instalment cap for large projects, in particular, provides the necessary flexibility to conduct testing in phases that align with project timelines and capacities.
For RLDCs and other grid operators, the explicit guidelines on scheduling and deviation settlements provide a framework to manage grid stability effectively. The emphasis on obtaining prior permissions and adhering to DSM regulations ensures that any potential imbalances caused by infirm
power injections are anticipated and managed proactively.
Overall, these guidelines by the CERC aim to balance the need for the efficient commissioning of renewable energy projects with the imperative of maintaining grid stability. By delineating clear procedures and offering flexibility in trial run scheduling, the CERC aims to facilitate a smoother transition for renewable energy projects from the commissioning phase to full commercial operation.
Going forward, by establishing clear protocols and providing the necessary flexibility to stakeholders, the CERC is paving the way for a more resilient and efficient electricity grid that can adeptly handle complexities associated with modern power generation and distribution.