India's first offshore wind farm will likely come up in Tamil Nadu. The sea off Rameswaram and Kanyakumari has been identified as potential sites for these windmills and tenders are planned to be floated in three months.
At nearly 7,500MW, Tamil Nadu's installed inland wind capacity has peaked, and offshore offers scope for expansion for this green source of power.
Though requiring no land purchase, onshore windmills come at a premium. Each wind turbine costs `25 crore -at least four times as much as a land windmill. These machines are also much harder to maintain and repair because of their location.
The Union government is planning to float tenders to lease out sea blocks to companies for setting up wind farm projects along India's 7,600km coastline. On September 9, the Union cabinet approved the national off shore wind energy policy . The approval paves the way for offshore wind energy development up to a distance of 200 nautical miles into the sea within the exclusive economic zone.
Apart from Tamil Nadu, Gujarat will also have offshore wind farms but it will take more than three years for Gujarat to get wind farms along the Kutch coast, officials say . According to National Institute of Wind Energy (NIWE), there is at least 1GW (1,000MW) of capacity each off Rameswaram and Kanyakumari coasts.
A major component of the cost is the setting up of the windmill's mast. “If the mast is to be 100 metres, then 50 metres will have to be under the sea. For this we need to have a pile foundation, which will account for 70% of the total cost,“ a senior NIWE offi cial told TOI.
“Two years back we set up a 100-metre mast with a windmill at Dhanushkodi. Based on the data collected from this windmill, we came to know that the area has high wind potential. Another mast we set up at the Thiruvalluvar statue in Kanyakumari gave similar results,“ the official said.
The offshore windmills will be set up with assistance from the European Union.“EU is the leader in this field and they have promised to give financial assistance to the extent of $4 million for setting up offshore wind farms in the country . Beyond this they will also train our companies on setting up wind farms as well as maintain them,“ said the NIWE official.UK, Germany and Denmark have much of the world's offshore wind capacity .