The main issue with ethanol production is the supply constraint, and for that reason it remains a niche product as it's far cheaper to extract oil from the grou

The main issue with ethanol production is the supply constraint, and for that reason it remains a niche product as it's far cheaper to extract oil from the ground. There are perhaps other promising bio-fuel production methods with higher yields, with respect to land use. Hybrid vehicles are still an economical option, preferably paired with high-efficiency ICEs, and could tide us over until better energy storage options become available.