A Sustainable Vendor–Buyer Supply Chain Framework Integrating Energy Storage Systems and Green Investments with Incentive Policies under Demand Uncertainty

This research evaluates the effects of integrating energy storage systems into supply chains comprising a vendor and a buyer governed by carbon tax regulations and augmented by green incentives, with an emphasis on promoting sustainability, lowering expenses, and preserving operational efficiency. In this study, a non-linear sustainable supply chain model is developed by incorporating an energy storage system and accounting for carbon emissions from various stages of the supply chain to reflect real-world complexities. In practice, carbon emissions are regulated by a carbon tax policy. Green technology investment is also incorporated to reduce carbon emissions in the supply chain. Besides lowering emissions, such investments can also reduce the energy required in the production process. To support these investments, the government provides green incentives, the amount of which is determined based on the achievement of emission reduction targets. The annual demand is modeled as a fuzzy variable to capture its imprecise nature. To address such uncertainties, Single-valued trapezoidal neutrosophic fuzzy parameters are employed in the model. The Lagrangian method is then applied to derive the optimal solution to the formulated problem. Finally, a numerical example and sensitivity analysis are presented to illustrate the application of the model and examine the impact of key parameters on model behaviour and performance. The proposed model was solved using the prescribed optimization method. The results indicate that the total integrated supply chain cost with investment in energy storage systems amounts to $10,054.23, whereas the cost without such investment is $11,693.77. This substantial reduction in total cost demonstrates that the implementation of energy storage systems significantly enhances the overall performance and cost-efficiency of the supply chain. The simultaneous incorporation of energy storage systems and green technology investments in a supply chain, alongside carbon taxes and green incentives under single-valued trapezoidal Neutrosophic fuzzy environments, has not yet been thoroughly investigated in the existing literature.