This paper provides in-depth analysis of the potential impact of demand –side management and energy efficiency improvements by evaluating energy consumption and efficiency according to the LVS EN ISO 50001:2012 standard at a glass-work company in Latvia. The electricity consumption monitoring system provides detailed data on energy consumption by the different types of production processes. In-depth analysis of production process energy consumption shows that glass tempering is included in almost all glass production processes and is the most energy- intensive process. By increasing the energy efficiency of the glass tempering process, the total energy consumption may diminish considerably, as may the share of electricity in the ultimate cost of the products, which is to result in diminished prime cost of the products. However, the process of refurbishing the glass tempering process is rather expensive and requires analysis as to the repayment of investment, considering the new law on the mandatory procurement component (MPC).