The pressure swing adsorption (PSA) units are widely used as an oxygen source. The storage of pressurized gaseous oxygen is limited by the capacity of a pressure vessel. The increasing share of renewable electricity sources (RES) causes intraday electricity price fluctuations. These fluctuations can be an opportunity to improve the economy of a plant. This paper aims to analyze the potential of a PSA unit connected to the battery energy storage system (BESS) for more effective on-site oxygen production. The analysis was carried out for the Czech Republic, Germany, and Denmark. These countries differ significantly in the energy mix. The theoretical potential of BESS installation and use in electricity price peak was found to be around 9 - 16 % of cost-saving on average compared with the daily operation of PSA unit when the off-peak average electricity price was from 95 to 91 % of the daily average electricity price respectively. Widening the price gap due to increasing RES share, the potential is growing.