Coimbatore located in the southern Indian state of Tamil Nadu is called the "Manchester of South India" because of its large textile industry, which is fed by the surrounding cotton fields. More than 150 medium and large textile companies reside in and around Coimbatore.The boilers used in these factories consume a lot of fuel, with temperature requirements of up to 80°C. This makes it ideal to use solar collector fields as pre-heating for the existing boilers. Thanks to good frame conditions, the systems can be paid back in less than one year, as the example of the Amudham Sizing Mill shows. Sizing is a preparatory process for weaving. The region’s hard water forces the companies to use systems based on vacuum tube (see photo) to overcome problems of calcification.
Photo: Jaideep Malaviya
The solar system with a daily hot water capacity of 2,500 litres was commissioned exactly 12 months ago. The solar heat is fed into an existing buffer tank with 2,000 litres.
The costs of the solar thermal collector field, including the insulated piping to the buffer tank, were close to Indian Rupee (INR) 750,000 (EUR 11,000). According to Mutthu Kumaraswmy, Managing Director of Amudham Sizing Mill, the solar thermal installationwill save up to 1,200 tons of firewood in the first year, equivalent to INR 95,000. Electricity can be reduced, too: Retrofitting the input & output fans for the ventilation in the fuel chamber of the oil or biomass backup boiler would save up to INR 7,000 monthly.
The industryalsoprofits from an accelerated depreciation, which allows companies to deduct 80 % of the investment costs on the first tax declaration after the investment. This saves another 32 % of the investment costs. The solar thermal system was operated on about 250 days over the last 12 months, which means the payback period is less than a year.
“More and more textile businesses want to profit from the advantages of solar water heaters,” Christo George, Chairman and Managing Director of the Hykon Group of Companies, confirms. “We have already delivered and installed around 10 systems in the textile industry in Coimbatore, such as the one at the Amudham Sizing Mill.” According to George, textile companies have already acknowledged that electricity costs, as well as firewood prices, will rise in the future. Oil is no longer a good option from an environmental point of view: investments in solar thermal areclearly the better choice.