CHENNAI: The VO Chidambaranar Port Authority in Thoothukudi will install a 6.25 MW wind turbine in sea and transmit the electricity generated to the State grid, in a Rs 77.41-crore project that would serve as India's first offshore wind-farm prototype.
The project, which involves installing a turbine on a foundation built on the seabed and laying a submarine cable to bring the power to the shore, is scheduled for completion within 12 months of the Letter of Acceptance.
Unlike conventional wind farms with multiple turbines, the proposed installation will have only one turbine; but the project will build experience in offshore installation, marine logistics, and grid connectivity.
The turbine will be located about 1.65 km from the southern breakwater of the existing Inner Harbour and around 1 km from the proposed southern breakwater of the Outer Harbour. The seabed at the site is about 9.7 metres below Chart Datum, the reference level used to measure water depth.
The contractor will have to conduct site-specific seabed and marine surveys before designing the foundation and installing the turbine. The work also includes supplying the vessels and lifting equipment required for offshore installation, laying the submarine export cable, and providing the associated electrical and control systems. The cable must be buried or otherwise protected as required.
Electricity generated by the turbine will be stepped up to 22 kV through a transformer and carried by the subsea cable to a Transition Joint Bay at the port's existing substation. From there, the power will be connected to the State grid. Onshore meters will record electricity exported to and imported from the grid in accordance with Tangedco and Tantransco norms.
The sequence includes detailed surveys and engineering, equipment procurement, foundation installation, cable laying, turbine installation, and electrical integration, followed by testing and commissioning. The contractor will also be responsible for the required environmental studies and statutory approvals.
The turbine will have three blades mounted on a tubular steel tower, with a minimum design life of 25 years. The contract, issued by Indian Port Rail - Ropeway Corporation Ltd (IPRCL) on behalf of the port, includes two years of operation and maintenance after commissioning.
After commissioning, the turbine must meet specified performance requirements, including at least 95% annual machine availability, an energy-production demonstration test and a 96-hour reliability run without faults or alarms.
India has pursued offshore wind development off Tamil Nadu and Gujarat coasts for more than a decade, but the sector has yet to take off.