Connecting Renewables

CERC proposes procedure for linking projects to ISTS

Smooth grid integration continues to be a challenge for the renewable energy sector in the country. Besides intermittent power generation and poor existing grid infrastructure, the lack of grid connectivity in remote areas is a key impediment to grid integration as most of the renewable energy capacity is installed in these areas. In this regard, the Central Electricity Regulatory Commission (CERC) has recently released a draft notification on the procedure to connect renewable energy projects to the interstate transmission system (ISTS). This grant of connectivity will be applicable to all renewable energy generation projects including hybrid projects, storage-based solar parks, wind farms and wind-solar power parks. It will also apply to the central transmission utility (CTU), Solar Energy Corporation of India (SECI), regional load despatch centres, state load despatch centres and state transmission utilities. The application for connectivity entails a two-stage process, and it can be filed separately or simultaneously.


Any renewable energy project (with or without storage) that has a capacity of 50 MW and above is eligible to connect to the ISTS as per this procedure. Also, any entity that acts as a lead generator for individual projects with less than 50 MW of capacity each but with 50 MW or more of cumulative capacity will be granted connectivity. If the capacity of an already connected project needs to be augmented, then a fresh application will have to be submitted as per this procedure. However, any solar power park developer that has a transmission system under implementation and has been granted connectivity but is yet to sign the bay application and any pending applications will be deemed as a grantee for stage-II connectivity subject to the fulfilment of certain conditions.

Stage-I connectivity

Stage-I connectivity can be applied for renewable energy projects through an online application upon payment of the application fee. The applications will then be scrutinised and any gaps or incomplete applications will be intimated to the applicants. The nodal agency will provide a week’s time to the applicant to rectify the mistakes, failing which 80 per cent of the fees would be refunded and the application rejected. Moreover, any applicant that does not apply for stage-II connectivity within 24 months from grant of stage-I connectivity will forfeit its status as a stage-I grantee along with the application fees. Meanwhile, if the entire or part connectivity granted under stage-I is not utilised for stage-II connectivity, the applicant will forfeit the unutilised capacity.

Once an application complete in all respects is received, the CTU will carry out the necessary study to provide the connectivity to the existing ISTS substations or to new ISTS substations under implementation. One primary and one alternate location will then be provided by the CTU to the applicant within 60 days of the last day of the month during which the application was received. Further, the CTU’s voltage level of the dedicated transmission line and the power carrying capacity will be notified to the applicant as follows:

The stage-I connectivity grantees are expected to provide quarterly updates of the development of the generation project and associated transmission infrastructure as per the format given by the CTU. The progress update will be utilised to implement the planned ISTS system and determine if any augmentation is required. At the same time, the CTU will provide quarterly updates of the ISTS transmission system required for the evacuation of power from the renewable projects.

Stage-II connectivity

Any stage-I connectivity grantee is eligible for stage-II connectivity if it has been selected by a central agency through competitive bidding for developing a renewable energy project, owns, or has leased, the land use rights for the land required for building stage-II connectivity, and has signed a power purchase agreement for more than 50 MW of capacity for a duration not less than seven years. Moreover, projects that have achieved financial closure and have released at least 10 per cent of the funds for project development through equity will be eligible. Failure to achieve the aforementioned eligibility criteria or provide proof for it will result in the cancellation of the stage-II connectivity grant.

The CTU will scrutinise the completed applications and intimate the applicant on any discrepancies to be rectified within a week, following which the completed applications will be processed. It may so happen that only a part of a project with stage-I connectivity is eligible for stage-II connectivity. In this case, the applicant will be granted connectivity for the eligible capacity. The CTU will verify the development of the generator pooling station by the renewable energy project developer. The CTU will then intimate the applicant about the grant of connectivity along with the bay number and single-line diagram or the scheduled commissioning date of the substation, whichever is applicable. The transmission agreement and submission of the bank guarantee for connectivity by the applicant will be made within 30 days, failing which the grant may be cancelled. Bank guarantees of Rs 100 million for connectivity of up to 80 MW (only for the north-eastern region), Rs 500 million for up to 300 MW, and another Rs 500 million for every 300 MW hereafter will be required. The bank guarantees will be discharged six months after the commencement of power evacuation from the renewable energy projects.

Details of the progress of stage-II connectivity will be updated quarterly by the grantee. The transmission lines and pooling substations must be completed within 24 months from the date of intimation of the bay allocation. Failing to deliver on the said timelines will result in the confiscation and encashment of the bank guarantees and stage-II connectivity will be revoked.

Technical requirements

The dedicated transmission infrastructure will be developed in compliance with the rules set by the Central Electricity Authority (CEA). The dedicated transmission line voltage will match that of the ISTS substation, to which it will be connected. The ISTS transmission licensee implementing the pooling station will, in coordination with the CEA, indicate the requirements for double circuit or multiple circuit towers. Based on the topology of the region, the CTU may plan to connect the renewable energy projects through loop-in-loop-out of the dedicated transmission line.

The planned capacity of the pooling station will not be less than the capacity of the dedicated transmission line, which will be terminated at the high voltage end of the developer’s pooling station. Meanwhile, the minimum aggregate evacuation capacity of the generator pooling station will not be less than 100 MVA.

Sharing of connectivity

The dedicated transmission infrastructure developed by the grantee will be of a definite capacity, which will not be limited to the capacity approved for connectivity. In case part of the infrastructure remains unutilised, it will be shared with other renewable project developers to ensure optimum use of the transmission system. This would make the grantee a lead generator, which will enter into an agreement with the other entities to undertake all operational and commercial responsibilities of the transmission system. However, any capital expenditure required to extend the infrastructure will be borne by the parties mutually. In the event of the sharing entities applying for stage-II connectivity, a one-time transmission charge of Rs 750 million for every 25 MW of capacity with an annual escalation of 3.5 per cent will be levied.

Transmission planning

The location and capacity of the ISTS pooling stations and facilities will depend on the wind and solar power potential of the designated areas as provided by the Ministry of New and Renewable Energy (MNRE). For this purpose, the CTU and the MNRE will work in tandem to ensure smoother evacuation of power from the renewable energy projects. The information on the transmission systems so developed will be provided to the standing committee for power system planning and will seek regulatory approval before implementation. The CTU will provide information on the implemented capacity of the ISTS substations to the central agencies for inclusion in any bids that will be invited to develop renewable energy projects.



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