CTUIL Advisory Clarifies Installed Capacity Mismatch, Technical Compliance for RE Projects

The Central Transmission Utility of India Ltd. (CTUIL) has issued a detailed advisory outlining the procedure for processing applications related to technical connection details of renewable energy (RE) generators, with a focus on installed capacity mismatches, inverter oversizing, and simulation requirements at the Point of Injection (PoI).

The advisory follows a regulatory relaxation granted by the Central Electricity Regulatory Commission (CERC) through its order dated December 8, 2025, aimed at addressing technical compliance challenges faced by renewable energy developers.

CTUIL stated that mismatches between installed capacity (IC) reflected in simulation study models and the capacity mentioned in connectivity grant letters will be assessed in line with CERC’s recent directions. CERC has relaxed the provisions of Regulation 5.1 of the CERC (Grant of Connectivity to Projects based on Renewable Sources) Regulations, 2022, allowing RE developers to install additional inverters, wind turbine generators (WTGs), or equivalent equipment solely to meet technical compliance requirements at the PoI.
The relaxation applies specifically to requirements related to reactive power compensation, internal losses (DTL losses), and other technical compliances. However, CTUIL clarified that active power injection at the PoI must not exceed the connectivity quantum already granted.

As per the CERC order, developers will not be required to furnish additional connectivity bank guarantees (Conn-BGs) or comply with Regulation 5.8 of the GNA Regulations for such additional capacity installed exclusively for technical compliance. CTUIL will validate the need for this additional capacity through system studies conducted under Conn-4 and permit only the quantum required for compliance.

Applicants seeking this exemption must submit an undertaking, as specified in Annexure-A of the advisory, detailing the breakup of active power delivery, reactive power requirements, internal losses, and any other technical compliances. These details must be substantiated through steady-state simulation study results.

CTUIL further noted that simulation studies must be carried out in accordance with the design temperature procedure issued by the Central Electricity Authority (CEA) on April 8, 2024. In cases where inverter capacity exceeds rated installed capacity due to lower ambient temperature requirements, such deviations must be explicitly disclosed in the technical connection details.

Developers are required to apply for additional generation capacity under Regulation 5.2 of the GNA Regulations, 2022, even when such capacity is installed solely for technical compliance and remains within the granted connectivity quantum. During the transition period, applications will be processed for issuance of detailed connection offers and subsequently regularised through regional Consultation Meetings for Evolving Transmission Schemes (CMETS). CTUIL noted that after the transition period, which will be notified separately, technical connection data applications will be taken up only after discussion in CMETS.

The advisory also confirmed that derating of wind turbines at high ambient temperatures will be considered during processing of technical connection details, in line with the Ministry of Power’s Office Memorandum dated September 30, 2025.

Additionally, CTUIL stated that technical connection details involving power transformer overloading beyond full rated capacity at Generator Pooling Stations will be processed in accordance with the minutes of the CEA meeting held on September 9, 2025, which addressed industry representations from WIPPA and NSEFI.

To ensure timely processing, CTUIL has capped revisions to simulation study reports at a maximum of three. Applications exceeding this limit will be closed, and entities will be required to submit fresh applications through the National Single Window System (NSWS) portal.

For faster evaluation, applicants must also submit Python-based automation files for batch processing of all RMS and EMT simulation cases, covering studies conducted on both PSSE and PSCAD platforms. CTUIL specified that the automation scripts must be clearly commented and structured to distinguish between steady-state, dynamic, and power quality simulations.

The advisory is expected to provide regulatory clarity and streamline the processing of connectivity applications for renewable energy projects, while maintaining grid security and technical compliance standards.