Businessworld has a Cover Story on the topic with special focus on the travails of wind energy in Tamilnadu , hydel energy in Uttarakhand and the emerging rooftop solar opportunity . Tamil Nadu has an installed capacity of 6,969 MW, or 40 per cent of our total wind energy capacity of 17,352 MW and 28 per cent of the total renewable energy capacity. Wind energy also accounts for 12.64 per cent of the electricity generated in the state (9,763 MU out of 77,218 MU). More than 95 per cent of the country’s wind energy potential is in the coastal states of Tamil Nadu, Andhra Pradesh, Karnataka, Maharashtra, and Gujarat. And while Karnataka has the largest potential, best wind sites are in Tamil Nadu. Four prominent passes in the state — Palghat, Shencottah, Aralvoimozhi and Kambam — have average annual wind speeds ranging from 18 km/hr to 25 km/hr. In Karnataka, the average is about 10 km/hr. Tamil Nadu, however, is power deficit — the average power availabil...