Ethanol: A Necessary Tool on a Path Towards Renewable Energy?

By Allison Markman

New York City, New York

Renewable energy graphic. (Via conservationinstitute.org)

Ethanol fuel is a renewable resource that is used across the U.S. in both gasoline to power cars and as a source of electricity. A biofuel made from sugars found in a variety of plant sources, in the U.S. it is typically created from corn. It is most commonly used for refueling cars, where most gasoline mixtures are now 10% ethanol by volume. Ethanol is produced by grinding biomass to a fine consistency, adding water and enzymes, then heating the mixture to break down the mixture into fermentable sugars. Yeast is then added to break the sugars into carbon dioxide and ethanol.


Despite being a renewable resource, many argue there are significant environmental effects of ethanol production. In the U.S., 90% of ethanol is produced in the Midwest, but it is used primarily on the East and West coasts. The production of ethanol requires growing a large amount of biomass sources, such as corn, beets, or sugarcane. Cultivating these crops requires a lot of water, and over time the mass production of these crops makes the soil less fertile. In addition, the transport of ethanol from the production sites to the coastal states is expensive and has additional pollutive impacts.

Although there are both positive and negative effects of ethanol, most gas in the U.S. still contains at least some of it, and its use has increased greatly over the past 40 years. ​​About two million gallons of fuel ethanol were consumed in 1981, and about 14.5 billion gallons were consumed in 2019. Biofuels, including ethanol, make up 17% of the market share. Currently, it is also used to generate electricity in some states.


For many, interest in ethanol stems from the unfamiliarity we have with it. Whenever I am driving with my family and we stop at the gas station, I always see the little sign on the machine that says 10% ethanol. I have never really stopped, however, to think about what that truly means, or where ethanol comes from. I was curious to explore why we include the source in gasoline and its environmental effects. Many who live in the city do not really consider cars that often because they are not something they don’t use regularly, but they are evidently major emitters.


In many ways, ethanol is a more environmentally friendly alternative to other fuel and electricity sources. Compared with natural gasses and fossil fuels, ethanol emits less toxic byproducts, and it does not release as much particulate matter into the atmosphere as coal. While ethanol does pose environmental problems, gasses, fossil fuels, and coal are significantly worse due to their larger emissions of CO2 and other harmful gasses that contribute significantly to the greenhouse effect and serve to raise global temperatures.

However, the cultivation of the corn required to create ethanol for fuel requires significant amounts of water and pesticides which are also harmful. In addition, the process of turning corn into ethanol emits carbon dioxide, just not to the same extent that coal does. Further, ethanol is produced primarily in the Midwest where land is readily available; however, it is used by both coasts of the U.S. This means that ethanol must be transported by truck to reach these places, which is another environmental complication with the resource. Land may also be cleared from food production to give room to create the fuel, as a lot of crops are required for the creation of fuel. There are also significant health effects of the production and combustion of ethanol. These processes can cause respiratory illness due to their carbon, particulate matter, and ozone emissions. As a result of these potential emissions issues, the long term effects if we continue to cultivate and expand ethanol production could include depletion of the ozone layer, deforestation, honey bee extinction, and many other environmental and health issues.


Economically, ethanol is less expensive than many of the newer renewables such as wind, solar, and nuclear energies. However, as research continues on, these forms of energy costs are expected to go down. Ethanol also contributes $34.7 billion to the U.S.’s GDP and employs 62,000 people. Indirectly, the ethanol industry created 243,600 jobs. In 2015, a study found that the cost of producing 1 kW of electricity from ethanol is between $3,500 to $4,400, whereas nuclear costs between $3,900 and $4,000, and solar costs between $3,300 and $5,300 dollars. Ethanol is more affordable than renewables but less affordable than natural gas and coal, which is expected because it has been used for the largest amount of time and its cultivation is easier than newer sources. Ethanol makes up 17% of renewable energy consumption and 1.4% of electricity consumption, but this number does not account for its use in the automotive industry. Ethanol is cost effective, creates jobs, and contributes significant revenue towards the U.S. economy.


There is little innovation in the field of ethanol due to the fact that the source and products are practically impossible to be altered. There is also an “ethanol subsidy” which awards blenders registered with the IRS a tax credit of 45 cents for every gallon of pure ethanol they blend with gasoline, which would also aid in ameliorating the financial burden of ethanol production. At large, the fuel is expected to decrease over time as well. Ethanol production declined in 2020 due to the pandemic having caused people to drive less; however, ethanol is currently beginning to revert back to its pre-pandemic demand. There is also some research on increasing the amount of ethanol in gasoline; however, currently car engines are not designed to function with a larger amount of ethanol.


At this moment in time ethanol is more environmentally friendly than fossil fuels and coal. It produces significantly less carbon, noxious gas, and particulate matter. In addition, it is an economically viable alternative fuel source, as it is less costly than both nuclear and solar electricity production. However, ethanol still causes significant environmental harm. As other renewable resources become more widely available and affordable, a transition to those resources would be more sustainable for the environment and a more viable option. As the electric grid is unable to withstand a complete shift to electric cars, improving gasoline-powered cars to be able to tolerate larger amounts of ethanol in fuel would also be a feasible option as it is better than gasoline, which makes up the larger percentage of cars’ fuel.