Even if it could be, I would be worried about the ecosystem- we need the oxygen produced by these vast fields of green goo. Sooner or later we will run out of algae - don’t you remember, that was the original source of Soylent Green until they ran out of algae ;O The same with water - I would rather have it for drinking than for fueling my car—there’s simply not enough potable water to squander it on car fuel. We need to change our thinking on Oil as “carbon-based.” I am in the Abiotic school of thought, i.e., oil is not from the oozy remains of dinosaurs and plants - rather, the earth is continuously cooking it deep down and squeezing it out all over the place. Only a fool would stop using it as a fuel.
Further proof that all of this stuff isn’t driven by worries about the environment, it’s all just more crony capitalism.