Case study of few recommendations in India
Installation of Solar roof top panels
In a textile unit in North India which is an H&M supplier we noticed that the factory has ample roof space to set a Solar PV system. Hence we analyzed the alternative to install on the roof top a solar panel to cater to at least a part of the existing electrical load. The factory operates for 8 hours a day and the shift starts from 8 AM to 5PM. As per available space on the roof it was recommended that approximately 100 kW roof top solar system could be installed which will provide 20%-25% of the net electricity demand of the unit.
Based on our recommendations the unit installed 110 kW capacity solar panels on the roof with a total investment of approx. 800 000 SEK, annual savings of 200 000 SEK and a payback period of four years. Annual GHG reduction of 143 tons is the expected outcome of the project.
Reuse for last wash water in Dyeing process of textile
Some sources of process water can be collected and reused for other processes instead of just discharging it directly to a wastewater treatment plant. For example: after dyeing, fabric must be rinsed multiple times – up to 4 rinses per batch of fabric, with each rinse consuming an average of 2.5 – 4 Kl of water per ton of fabric. With each successive rinse, the effluent becomes cleaner. Factories that reuse the last rinse water as a feed for the first rinse can save huge amounts of water. With the same practice, the factory could save more than 9 percent of total water consumption. While even the smallest presence of dye may render this water unsuitable for reuse in some equipment, this practice is a safe way to reuse rinsing water at least during the same color run or when going from lighter to darker shades.
In other circumstances, this best practice requires purchasing pipes, water tanks, and electrical pumps to store and return rinse water to the process. Estimates of investment cost range from less than 26 000 to 33 000 SEK per dye machine for most mills, with an overall fresh water reduction of 9-10%. Similarly the impact would be the same on wastewater generated by the factory which would further add to savings of chemical treatment of effluent in ETP.
In a textile unit in North India, an IKEA supplier, we analyzed that by reusing the last wash water in the dyeing process of textiles, about 2.6 million liters of water could be potentially saved. This process resulted also in savings of chemical treatment of effluent in ETP and electricity consumption.
Installation of Variable Frequency Drive (VFD) fan in Thermopack
Thermopack is closed from all sides to save release of energy. Forced Draft fans are used to feed air inside a thermopack to keep the fuel burning and generating energy. After the burning of the fuel, residual wastes such as gases or ash are generated. Draft fans are used to blow these ash particles and gases out in order to remove this waste.
One factory in India connected a 22 kW FD and a 30 kW ID fan to the thermopack. Dampers were used to control the flow of air for both fans. The operation person told us that both fans operated in throttled condition most of the time. The dampers were always at 60% closed position which implied that the dampers were creating a mechanical resistance on the flow path of the air. We decided to apply VFD which reduced the speed of the fan by lowering the frequency of power and thereby saving energy. 10% reduction in the speed of the fan normally reduces the power consumption by 27%. A result which cannot be achieved by operating via dampers. Installing VFD fans has contributed to 0.5% saving of the total power consumption by the factory.
This project required an estimated investment of 35 000 SEK. It resulted in annual savings of 100 000 SEK, a payback of 3-4 months and a reduction of 100 tons of greenhouse gas emissions (GHGs).
We also created a Water Governance Report for India to help map the water risks for the textile industry there.