Even if it's the most efficient energy improvement in history, it can still be best thing to focus on making more efficient. The best thing to target for improv

Even if it's the most efficient energy improvement in history, it can still be best thing to focus on making more efficient. The best thing to target for improvement is that which has the best output from a function of highest impact and lowest effort. Making cargo ships 0.5% more efficient could still be the lowest effort, highest impact returns on energy (hypothetically, I don't actually know).