Is your argument that renewables aren’t usable for liquid fuels in ocean shipping, therefore we can’t use purely renewable energy sources? Because solar panels (or wind turbines, or geothermal, or hydro, etc.) can generate electricity to use for electrolysis to generate hydrogen (or better, ammonia). The options aren’t only oil or batteries… there are many use cases where fuel energy density doesn’t matter that much, but where it does (transport), hydrogen is a viable option that we can do today.

https://www.bbc.com/future/article/20201127-how-hydrogen-fue...