In light of India's current energy crisis, it has been determined that the coal mining industry may be used to implement Demand Side Management (DSM) applications. This study explores the possibility of energy savings and reduction in energy costs associated with the installation of (Variable Speed Drives) VSDs on primary ventilation fans in below-ground coal mines. According to Ventilation-on-Demand (VOD), where air volume is changed according to demand at various time intervals, a nonlinear constraint optimization model is created to reduce energy costs and achieve better energy efficiency. To achieve accurate results at the fan's operating point, this model is also constructed to adhere to the affinity law of the fan. Tellegen's theorem and Kirchhoff's law are applied to model the ventilation system of the underground mine. The ventilation network was used to investigate energy and financial savings with various airflow scenarios. Load management is accomplished by figuring out the ideal start time for the mining schedule in accordance with the Time of Use (TOU) tariffs. A critical analysis of the Tandsi underground coal mine is presented to explain the impacts of the optimization model. The study found that implementing DSM solutions could result in a total annual energy savings of 118625 kWh, or a reduction in energy costs of USD 22995.