When will it become accepted practice that renewable methanol is used as a fuel for powering long-distance ocean-going vessels?
Ambitions for zero emission maritime operations by 2030 require new power sources. Renewable methanol is produced from an electrolysis process, powered from a renewable energy source. The process combines hydrogen with CO2 captured from the air or the emissions from an industry, making it carbon neutral. 
Liquid methanol needs neither compression nor cooling, making it easy to handle and cheap to transport. Infrastructure at many important ports has already been established, but it will need retrofitting for refuelling ships. [1,2] Furthermore, although some gas carrying ships and ferries are using non-renewable methanol for a fuel source, large ocean-going ships will need to be built or converted for liquid methanol and the fuel will need to be sourced sustainably. 
The amount of renewable methanol needed to power large ocean going vessels would require a scale of production of great magnitude. Electrical grid power is too expensive to produce methanol. Solutions could be to locate production alongside nuclear power plants or dedicated wind, solar, or tidal energy farms.
 Chemical storage of wind energy by renewable methanol production : Feasibility analysis using a multi-criteria decision matrix / 10.1016/j.energy.2015.09.043