Power-to-methanol (PtM) technologies have a potential to store excess renewable energy in methanol molecules. However, there is a lack of understanding about the role of these technologies in the course of energy transition. In this research, the influence of PtM technologies on power grid’s reliability and CO2 reduction are studied. An agent-based model is developed in order to explore possible future scenarios created by deployment of PtM technologies, in case green methanol is primarily supplied to the shipping sector as an alternative low-carbon fuel. The model outcomes are explored using two sets of experiments representing two hypothetical cases: "flexible grid" experiments in which the power grid is assumed to have several flexibility options, and "low flexibility" grid that the grid cannot easily adapt to high levels of renewable power production. The results show that deployment of PtM technologies can help with absorbing excess renewable energy and improving the reliability of the power grid. However, PtM alone is not sufficient to keep the grid reliable. PtM is shown to be successful in enabling high levels of CO2 reduction. The results obtained in this research can be used as the starting point to open up a discussion between system operator and policy makers in order to define a proper support plan for PtM or other Power-to-X (PtX) options.