CHENNAI: After three years of stagnation, Tamil Nadu is under compulsion to install additional wind generation capacity to comply with the renewable power obligation (RPO) norms prescribed by the Central Electricity Regulatory Commission In line with the central commission’s norms, the Tamil Nadu Electricity Regulatory Commission recently gave its nod to Tangedco to purchase 440.64MW of wind power by floating tenders. It means additional wind power mills have to be installed in the state to meet the requirement. The state has 9,286MW wind power generation installed capacity. However, evacuation is only around 5,000MW.The pace of growth has been slow in recent years owing to poor response to tenders floated by Tangedco to set up new windmills. A few tenders awarded to wind power companies in 2017 are yet to be commissioned. Moreover, only 70-75% of windmills are functional. The oldest ones with less than 1MW capacity are mostly non-functional and need to be repowered – replaced with higher capacity wind mills. Capacity of windmills in the state varies from 225KW to 2.1MW. Ones with low capacity are not being promoted now.As per TNERC guidelines, the new tenders will be floated by Solar Energy Corporation of India (SECI) for Tangedco to meet the RPO for 2021-22.The TNERC has approved a proposal to purchase 440.64MW of wind power through SECI for 25 years at Rs 2.84 plus Rs 0.07 as trading margin, totalling Rs 2.91 per unit to meet Tangedco’s non-solar RPO requirement from 2021-22, said TNERC in its order.The rate at which Tangedco is set to purchase power now is much lower than what it had finalised with wind power generation firms in the past.“Tangedco had floated a tender in Phase-I for 500MW at Rs 3.46 a unit as upper limit based on the all-India wind tender floated by SECI. Only 450MW of the 500MW was finalized then. PPA was signed with two companies for supplying wind power for 25 years at Rs 3.42 per unit,” said a senior Tangedco official.But so far, one company has commissioned only 49.5MW of 200MW allotted to it and another company is yet to start the project. “There was lack of response from bidders even after extension of deadline twice for participating in the bid last year. Due to the poor response, further addition of 500MW could not be processed,” said the official.“Since we have improved transmission facilities by adding new sub-stations, wind power evacuation will be substantially more in the coming years,” the official said.Tamil Nadu is also the first state to use GPS in windmills. “With the new billing scheme, it is easy for us to know the wind power generation on a real-time basis. We depend on forecast for power schedule, but with GPS, we are able to know the wind generation live,” said the official.