I write all the time about solar energy and the blossoming solar industry, but what about ethanol? What is it and how does it compare to solar?

Ethanol is the same type of alcohol you’ll find in your beer or whiskey. Ethanol, as a biofuel, is relatively easy to manufacture and process and is a native crop to the Americas; perhaps why you find it blended with gasoline at pumps across the nation. Ethanol can be produced from sugar cane and maize (corn). Logically then, it is no surprise that the United States (corn) and Brazil (sugar cane) are the far-and-away world leaders in ethanol production and use.

So, if ethanol is a biofuel and, when it is burnt, does not give off greenhouse gases, why is there so much controversy surrounding it here in the United States? The first and most recognizable reason is that it requires so much arable land to grow that it competes with corn used for food. Secondly, the life-cycle of ethanol is not as green as you might think. Corn ethanol has a rather mediocre energy balance. In other words, for every 1 unit of fossil fuel energy put into ethanol’s production, only 1.34 units of energy are released when the fuel burns. There is minimal displacement of negative energy. To be fair, there are contradictory reports regarding ethanol’s energy balance. Nonetheless, I have found none that are exceptionally favorable (although ethanol produced from sugar cane has a much better energy balance (1:8), check out Brazil’s fascinating achievements.)

For these reasons ethanol has fallen out of favor with many clean energy supporters. But don’t count it out just yet. Cellulosic ethanol, a biofuel made from wood, grasses, and non-edible portions of plants, may be the fuel’s saving grace. This type of fuel can be made from corn stover (corn stalks and leaves) and wood chips. In other words, it need not compete with the food supply and reduces greenhouse gas emissions by a considerably higher amount than standard corn ethanol.

So what about solar energy and ethanol? At this point in time, there is not much competition between the two. Ethanol, in some form, is already poised to be a big source of fuel for cars. Solar energy can also power cars and, as you can imagine, in a very clean way. But as of yet solar cars are still very much a niche market, if a market at all. They are reserved mostly for competitions and university studies, although some car makers are getting ready to put solar powered cars in storefronts around the world.

For now, solar and ethanol are both working toward the same goal. There are cleaner sources of biofuels, such as biodiesel, and but for cellulosic ethanol I might claim ethanol as a dying fuel source (at least in North America). But we shall see. At this point in time ethanol, and biodiesel, represent ways to clean up the millions of existing cars on the road while solar cars may become our grand transition to eco-friendly transit.

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Posted on August 8th in Solar Information by David.