There’s been so much hype about biofuels which are a technology that cannot at present make even a dent in our fossil fuel usage and put enormous pressure on both the ecosystem and food prices. It’s time to inject a dose of realism by demonstrating the scale of the issue, so here are some facts and figures all of which are freely available.
The numbers around biofuels are easy to calculate and clearly show that they are not a replacement for fossil fuels. Let’s look at jet fuel in the US to start. Biological Jet fuel comes mostly from oilseeds like Rapeseed (aka Canola), Peanuts, and Soy as well as other plants like palm and coconut. Although palm and coconut have higher yields per acre than oilseeds they cannot be grown in quantity in the US so this example will use Rapeseed which has the highest yield of oil seed crops at 102 gallons per acre. According to the US Bureau of Transportation Statistics the US uses about 13 billion gallons of jet fuel per year, and at 102 gallons per acre that means we would use about 130,000,000 acres of cropland to supply Jet fuel from biological sources. The US has 406,000,000 acres of cropland so it would take a whopping %31 of all US cropland to supply Jet-fuel needs alone! In 2007 the US used 44 billion gallons of Diesel which uses the same feedstock plants as Jet fuel, so using the same yield figures that would take 431,000,000 acres of cropland to supply, that’s 106% of US cropland.
So in order to supply Jet and Diesel fuels from domestic farming in the US would take %37 more cropland than the US posesses, and that’s before we even touch Gasoline and Avgas use which by the way is 136 billion gallons per year. Since Ethanol only has 80% of the energy density of gasoline we will need to grow enough corn for 170 billion gallons of Ethanol to replace gasoline. Corn yields 390 gallons of Ethanol per acre, so we will need 436,000,000 acres of land to grow enough ethanol to replace gasoline, which is 107% of US cropland.
In other words we would need 2 and a half times more cropland than we actually have to grow enough biomass to replace our transportation fuel use. Even if we turned over every single acre of cropland we have to biofuel production we would only supply 40% of our transportation fuel needs and we wouldn’t have anything to eat!
The ecological concerns of biofuel productions are worth mentioning as well. Indications are that the US is already overfarming available land, and the result is topsoil loss and more critically in many areas water resources are becoming exhausted. This means that in the mid to long term the US will have to farm LESS, not more to be sustainable.
If we push biofuels as a solution to fuel imports we will drive up our food prices dramatically, and also reduce the surplus food that is used to help feed the world’s hungry. As the world’s population continues to grow there will be more and more pressure on farming to keep food on the table, and I for one am not willing to have kids starve so I can have supposedly “green” fuel!
We cannot supply our transportation fuel needs using biofuels as there simply isn’t enough land and fresh water to grow the biomass needed to supply fuel and feed the population, in fact we can’t even make a dent in our fossil fuel use. I’m not anti-biofuels, there should be a place for them in our fuel economy, however we need to do so in such a way that they will not take food from hungry mouths and drive up food prices. Like it or not the reality of the situation is that we will be putting fossil fuels in our airplanes for a good while yet until substantial research and development produces viable green energy solutions. Food first, fuel second!