(This is part VIII of this series on energy. We hope it helps the reader better understand the issues facing our country and our state as we endeavor to tackle the problem of providing our citizens and our businesses with their energy needs.)
- The term “biomass” refers to non-fossil organic materials that can be used as energy sources.
* There are three main types of biomass:
- Biowaste, which are organic materials that are generally byproducts or waste products. An example of such is the methane gas that is collected from landfills and used to generate electricity and heat homes.  
- Biofuels, which are primarily produced from plants and used for transportation. An example of such is ethanol, which is used in cars and mainly produced from corn, sugarcane, and sugar beets.  
Wood, which has traditionally been the largest source of biomass for the U.S. and the largest of all energy sources for developing nations.  
- Biomass, particularly wood, was the first inanimate energy source that mankind learned to harness. Up through the Middle Ages, wood remained the primary fuel of civilization.
- The world’s first internal combustion engine ran on a mixture of ethanol and turpentine refined from pine trees. The world’s first diesel engine ran on peanut oil.
- In 2015, biomass supplied 4.8% of all primary energy consumed in the United States. Wood comprised 2.1 percentage points of this total, biofuels 2.2 percentage points, and biowaste 0.5 percentage point:
In 2015, biomass supplied:
- 7.3% of the energy consumed in the industrial sector. 
- 4.9% of the energy consumed in the transportation sector.
- 2.1% of the energy consumed in the residential sector.
- 0.7% of the energy consumed in the commercial sector.
- Ethanol is the dominant biofuel in the U.S. and globally.  
- In late 1970’s, the federal government began promoting domestic biofuels by subsidizing the production of domestic ethanol and placing tariffs on ethanol imports.
- Federal laws passed in 2005 and 2007 mandate that increasing volumes of biofuels be used in the U.S. transportation sector through 2022.  
Due primarily to these laws,  the portion of automotive fuel that is comprised of ethanol has risen from 2.9% in 2005 to 9.9% in 2015:
* Ethanol is another name for ethyl alcohol or grain alcohol, and it is chemically identical to the intoxicating ingredient in alcoholic beverages.
Before shipping ethanol, producers make it unfit for human consumption by adding inedible substances to it.
* Ethanol has higher octane than gasoline, which increases engine power. 
* The energy content per unit volume of ethanol is 31% below that of gasoline, which reduces fuel economy and hence vehicle range.  
* The elemental differences between ethanol and gasoline restrict the amount of ethanol that can be used in many engines and fuel systems. As compared to gasoline, ethanol:
is more corrosive to certain metals. erodes certain elastomers and plastics, including those sometimes used in fuel lines, gas tanks, and seals. acts as a solvent that can strip away certain lubricants and coatings. causes certain engines to run leaner and hotter, which can reduce engine life and catalytic converter efficacy. attracts water, which can cause corrosion and permanent engine damage.
* Whether or not the above effects occur depends upon the designs of engines and fuel systems, the concentrations of ethanol, exposure timeframes, and other variables such as pressure and temperature.
* Federal law prohibits material changes to automotive fuels and additives without approval from the Environmental Protection Agency (EPA). In 1979, EPA approved the use of automotive fuel comprised of up to 10% ethanol by volume. 
* In the late 2000s, a combination of the following factors created a situation in which almost all general-purpose gasoline sold in the U.S. contained 10% ethanol by volume:
Federal mandates requiring increasing usage of biofuels. 
Federal restrictions on the amount of ethanol that can be blended with general-purpose gasoline, 
Economic malaise, vehicle efficiency increases, and other factors that suppressed the use of transportation fuels.  
* In 2015, nearly all ethanol consumed in the U.S. was used in a fuel called E10, which is a blend of 10% ethanol and 90% gasoline.  Per the U.S. Energy Information Administration (EIA):
“The saturation of the United States’ gasoline supply with ethanol sold as E10” is called the “blend wall.”
“The term ‘blend wall’ describes the situation in the ethanol market as it nears the saturation point (at the 10 percent content level) due to limited ability to distribute or use additional ethanol….”
* In response to the looming blend wall, in 2009 a coalition of ethanol producers petitioned the EPA to allow for general usage of E15, which is a blend of 15% ethanol and 85% gasoline. 
* In 2010, EPA approved the use of E15 for model year 2007 and later general-purpose autos, and in 2011 EPA extended this approval to cars with models years of 2001 and later. However, EPA did not approve the use of E15 in older cars, heavy-duty vehicles, motorcycles, boats, lawnmowers, chainsaws, and other nonroad equipment.   Per EPA:
“E15 can significantly impair the emissions control technology in MY2000 [model year 2000] and older light-duty motor vehicles, heavy-duty gasoline engines and vehicles, highway and off-highway motorcycles, and all nonroad products.”
“ethanol enleans the A/F [air-to-fuel] ratio; this may lead to emissions products that can cause increased exhaust gas temperatures and, over time, incremental deterioration of emission control hardware and performance. Enleanment can also lead to catalyst failure.”
“Additionally, ethanol can cause material compatibility issues which may lead to other component failure.”
* In the wake of EPA’s rulings, the following factors have limited the usage of E15:
As of 2011, “laws and regulations in about three dozen states … restrict gasoline with more than 10% ethanol.”
Automakers, including BMW, Chrysler, Ford, Honda, Hyundai, Kia, Mazda, Mercedes-Benz, Nissan, Toyota, Volkswagen and Volvo, have expressed varying levels of concern about possible damage from using E15 in their vehicles, including cars with models years of 2001 and later. In 2011, some of the manufacturers stated that using E15 could damage engines and void warranties. 
“[M]any fuel retailers are concerned about potential liability issues if consumers misfuel their older automobiles or nonroad engines with E15.” 
To dispense E15, most service stations would have to make infrastructure investments including specialized fuel tanks and/or mixing pumps.  
* Certain autos called “flex-fuel vehicles” are designed to run on wide-ranging fuel mixtures up to 85% ethanol (E85). In 2012, 4.9% of light duty automobiles could run on E85, and 1.6% of gas stations dispensed E85.  
* Due to the blend wall and other practical limitations on the usage of biofuels, the EPA used its regulatory authority to reduce the amount of biofuels required by federal law in 2014, 2015, and 2016. 
* Federal law also mandates the usage of biofuels that produce less greenhouse gases than corn-based ethanol. One of these fuels is cellulosic biofuel, which is made from grasses, crop waste, and trees.    
* In 2007, when the mandate for cellulosic biofuels became law, such fuels were not being produced in commercial quantities. The law specifies how much of these fuels are to be used starting in 2010, but before the outset of each year, EPA is required to project how much this fuel will actually be produced and to relax the mandate accordingly. 
* For 2010, EPA lowered the law’s cellulosic biofuel mandate by 94%, but none of the fuel was actually produced. For 2011, EPA lowered the mandate by 98%, but none of the fuel was produced, and EPA leveled fines of $6.8 million on motor fuel suppliers for failing to use the nonexistent fuel. For 2012, EPA lowered the mandate by 98%, but a federal appeals court struck it down because EPA had not used a “neutral methodology” to set the mandate. EPA lowered the mandate by 99% in 2013, 98% in 2014, 96% in 2015, and 95% in 2016.     
* As opposed to petroleum and refined petroleum fuels—which are primarily transported to wholesale terminals via pipelines—ethanol is mainly transported to wholesale terminals by rail, trucks, and barges. Generally, the most economical and safest way to transport liquid fuels is through pipelines, but wide-ranging technical and logistical issues currently prevent most ethanol from being transported in this manner. 
\* Per EIA’s International Energy Outlook 2016, biofuel production “often depends heavily on policies or mandates to support growth.” This report projects that by 2040, biofuels will account for 7% of U.S. liquid fuels production (by volume) and 3% of global liquid fuels production.