Methanol is a primary petrochemical globally. Green methanol, produced by Power-to-X technologies, is a potential solution to the defossilisation of the existing methanol supply and fossil fuel substitution. This study investigates the optimal system configuration for the lowest cost green e-methanol production from electrolytic hydrogen and atmospheric carbon dioxide based on an hourly power supply by hybrid PV-wind systems in a 0.45 degrees x 0.45 degrees spatial resolution. Results suggest that, by 2030, solar PV will be the dominating electricity generation technology in most parts of the world. For a weighted average cost of capital of 7%, e-methanol could be produced for a cost range of 1200-1500, 600-680, 390-430 and 315-350 <euro> per tMeOH (189-236, 94-104, 61-68 and 50-54 <euro> per MWhMeOH,HHV) at the best sites in 2020, 2030, 2040 and 2050, respectively. By 2040, the production cost of e-methanol will be within the market prices, suggesting that methanol supply could be defossilised at no extra cost for consumers. Conversely, e-methanol costs remain higher than the cost of natural gas-based methanol for fuel prices below 11 USD per MBtu. However, the introduction of up to 150 <euro> per tCO2 emissions cost could increase the cost of natural gas-based methanol to about 300 <euro> per tMeOH (47 <euro> per MWhMeOH,HHV), thus significantly improving the cost competitiveness of e-methanol in the market. The production cost of green methanol from renewable electricity-based hydrogen and atmospheric carbon dioxide could reach market prices by 2040, making it a potential solution for defossilisation of the global chemical industry and marine transport.