The article discusses the issue of energy storage in the form of alternative fuels. Installations for producing methanol based on hydrogen from electrolysis (powered by surplus energy from a 40 MW wind farm during the night valley period) and CO2 captured from the flue gas of a conventional power plant as a reference variant are presented. The methodology for assessing the thermodynamic efficiency of the analyzed installation is presented. The location of potential sources of waste heat in the installation was identified. Two solutions have been proposed to increase the efficiency of the installation, i.e. replacing raw gas methanol throttling with an expander together with the combustion of separated residual gases from the installation and the use of waste heat (low temperature) by integrating the installation with the ORC module. The results of the analysis were presented in a wide range of the ratio of power supplied for electrolysis to the power of a wind farm (1-45%). Both efficiency and streams of manufactured products were compared.