Industry is responsible for approximately 25% of global greenhouse gas (GHG) emissions, contributing substantially to climate change. Sustainable manufacturing has therefore become a significant topic of discussion, resulting in a better understanding of key GHG emitters in milling processes. This paper investigates the influence of different compositions of the German electricity mix on the CO2-eq. Emissions of a milled steel disc defined by the Product Carbon Footprint (PCF). Using more wind and solar energy reduces CO2-eq. Emissions significantly in comparison to an energy mix almost without green energy types. The cradle-to-gate PCF of the investigated steel workpiece ranges from 8.44 to 11.91 kg CO2-eq., corresponding to a 41.18% increase caused solely by alternations in the energy mix composition. Feed rate was selected as the parameter for the optimization of the PCF, suggesting maximizing the feed rate to shorten production times. Emissions directly attributable to the milling process can be reduced by 11.59% and 16.93%, respectively in the two scenarios. Expected increase in cost and varying surface quality due to increased tool wear were not part of this investigation. This approach demonstrates the potential for environmentally sustainable manufacturing strategies by integrating electricity mix data into manufacturing parameter decisions.