Sustainable Waste-to-Watts: A Modular Bi2Te3 Thermoelectric System for Textile Waste Valorization

Global textile production generates over 100 million tonnes of cutting scraps and end-of-life garments annually, most of which are landfilled or incinerated, releasing greenhouse gases and microplastics. To valorize this waste and harvest lowgrade heat, we introduce a circular ”sandwich” prototype combining dark-dyed acrylic–wool off-cuts with commercial 40 × 40 mm Bi₂Te₃thermoelectric modules. In laboratory trials under 1 000 W/m² simulated solar irradiation, each module produced an average 0.43 W (≈4.3 % conversion efficiency) and stored 2.18 Wh in a 5-h charge test via an MPPT boost-charger into a 3.7 V Li-ion cell. Scaling to a 30-panel array at an industrial partner‘s facility (Kapoor Overseas) delivered 129 W peak and 654 Wh/day, sufficient to power temperature sensors, LED indicators, and ventilation fans continuously. A preliminary technoeconomic analysis estimates a capital cost of ₹2 000/W, a 5–6 year payback at ₹7.5/kWh tariff, and an LCOE of ₹8–10/kWh. Our results demonstrate that waste-fabric‐based thermoelectric harvesting is a viable complement to photovoltaics, especially under diffuse light and in modular deployments. We outline future directions—enhanced cooling, UV-protective coatings, hybrid PVTEG integration, and smart load matching—to further improve performance and drive commercial adoption.