Spinning mills in the textile belt of Coimbatore and Tirupur have begun hunting for investors to fund small solar farms on the rooftops of their factories as power can be consumed directly, with minimal wheeling or transmission charges for the energy as opposed to drawing power from distant solar farms or state -provided grid power. It is safer development models in renewable energy.

Investor interest in funding small, rooftop units in the south have picked up due to attractive returns from a round-the-year textile industry.

Coimbatore-based denims manufacturer KG fabriks was one of the earliest to go for a rooftop solar plant after the Alpine Group. Srihari

Balakrishnan, who heads KG, said that their rooftop solar unit takes care of about 20% of their power needs, while the rest is met through wind power and thermal power. Till now, the rooftop plant has generated close to 16 lakh units.

Tamil Nadu's spinning industry with a yarn manufacturing capacity of 2.25 crore spindles, had had several plunges into renewable energy. A large portion of small and medium mills have gone for wind farms and some into solar farms developed by independent power producers. Wind power turned problematic after the industry and the state locked horns over the state's backing out wind farms - cutting off turbines when supply exceeded demand during wind seasons. Gamesa, a wind power developer, had even begun selling solar projects to the state textile industry to tap into the demand-supply gap in renewable power.

Prabhu Damodharan, secretary, Indian Texpreneurs Federation said that a back-of-the-envelope calculation shows rooftop solar farm is an attractive option for investors. The Indian Texpreneurs Federation has invited three solar power developers to negotiate terms for development of about 50 MW of rooftop plants in the first phase of this drive.

In most of the spinning mills in Tamil Nadu, the rooftop can accommodate solar plants to the capacity of 1-3 MW . According to Textile Industry representatives, there is potential to develop well over 500 MW of rooftop solar systems in Tamil Nadu. Also due the cost of photo-voltaic modules and other components set to reduce further, resulting in higher earnings for long-term investors in rooftop solar power.

According to the state electricity regulator's latest paper, the cost of raising solar plants revolves around Rs 5.05 crore per MW