Editor's Note: John Beams, a student in Michigan with no professional connections in the green car industry, is an AutoblogGreen reader. Recently, he wrote the following essay and asked us if we wanted to publish it. We read it, liked it, and so here ya go. If you've been working on a bit of writing you think your fellow ABG readers would be interested in, go ahead and contact us. We'll see what we can do.

It is becoming more widely known that switchgrass [1] is one of the best possible sources for biofuel in the coming years. Primarily because of its incredibly high biomass yield per acre, with the advantages of being a low maintenance perennial crop, tolerance to pests and many climates, and other advantages. [2]

I was curious about how efficient ethanol really was, compared to some alternatives, which led me to research this and derive some figures. If you want to skip the math, my conclusions are at the bottom.

A single acre of switchgrass under research conditions has been shown to produce an average dry biomass yield of 11.5 tons per acre over 6 years, with a record high of 15 tons per acre. With ethanol production as high as 100 gallons per ton using the still-in-development cellulosic conversion process, a good switchgrass crop could produce as many as 1,500 gallons of ethanol fuel per year. [3] Using standard sugar alcohol conversion, sugarcane can produce about 665 gallons per acre, while corn comes in around 400. [4] See here for more corn vs. solar numbers.

The actual commercial yield of per acre of switchgrass is probably closer to 6-8 tons per acre [2], but I will give it the benefit of the doubt, and assume for the purposes of this article that it can average 10 tons per acre when proper cultivars are chosen for the growing conditions. If you wish to be more optimistic, you can multiply any figures I get for switchgrass by 1.5, to get the 15 tons per acre.

Read those numbers, and much more, after the jump