Biomass is the epitome of renewable energy. Biomass is energy made from any organic material from plants or animals according to the US Department of Energy (DOE). It is the process of reusing part of something that was alive to create electricity. Biomass forms include municipal solid wastes (MSW), agricultural and forestry residues, industrial wastes, and agricultural crops.

Municipal solid wastes

MSW is the garbage that everyone produces. The amount of garbage the average American produces daily is rising. In 1960 the average American produced 2.7 pounds of garbage daily. Today that amount has increased to 4.5 pounds, according to the Environmental Protection Agency.

By storing MSW in landfills, methane gas is naturally produced. That methane can be collected and burned to create steam in power plants which will spin turbines, creating electricity. Since methane is a stronger greenhouse gas than carbon dioxide, collecting and burning methane to produce electricity could meet renewable standards in the future, according to the Energy Information Administration (EIA).

Methane gas that is collected from landfills is becoming more popular. More than 100 biomass plants in 31 states burn methane gas generated from landfills, according to the Natural Resources Defense Council.

In waste-to-energy plants, MSW is burned to create steam to spin turbines. The EPA heavily regulates waste-to-energy plants to make sure pollutants do not escape from their smokestacks. Since MSW is burned at 1,800 to 2,000 degrees Fahrenheit, many harmful pollutants breakdown to simpler chemicals, according to the EIA. Since there is a lot of transportation and regulation involved with waste-to-energy plants, the cost to produce electricity is more than many other forms, including coal or hydropower.

Agricultural and forestry residue

Just like MSW, animals and forests produce waste. On dairy farms across the US, animal waste is collected and put into digesters. Inside a digester, animal waste emits methane gas. Just like in a landfill, the methane gas is collected and used to produce electricity on the farm, or the gas is sold to an energy company. Currently 6% of dairy farmers in California are under contract with a company that uses digesters to produce methane gas from farm waste according to Dairy Today.

Forestry residues can be used as a bio-fuel as well. After timber has been harvested for industrial use, there is a lot of residue left in the forest. This can include branches, bark, wood chips, and stumps. In Sweden, companies harvest the forestry residues after a timber company has harvested. The residues are then cleaned and used as bio-fuel to run steam power plants, according to Texas A&M University.

Even though burning forestry residues releases carbon into the atmosphere, trees are a renewable energy source that consumes carbon through photosynthesis. Harvesting forestry residues can be harmful for forests if simple precautions are not taken such as not taking 100 percent of the residues, avoiding harvesting on sensitive sites, and not removing residues after every harvest, according to Dr. Darwin Foster, Texas Cooperative Extension forestry program leader. To help harvested forests, sometimes the ash from the combusted residue is returned to the forest floor.

Industrial wastes

In any industry, manufacturing will produce byproducts. In some cases, the byproducts have more value than others, or can even be considered biomass. Byproducts of the timber industry are biomass, as well as in other industries that involve the use of wood. Excess wood can be burned in a power plant that uses stream driven turbines. The burning wood heats a liquid that vaporizes and is then forced through the blades of a turbine, which generates electricity.

Other industrial wastes can be considered biomass as well. Some textiles can be burned in power plants that use steam driven turbines, according to the Biomass Energy Centre. Even paper that cannot be recycled can be used in these power plants.

Agricultural crops

Crops grown across the world can provide renewable energy. Ethanol and biodiesel fuels typically derive from corn and soybean crops in the US, but cellulosic vegetation may soon replace, or supplement corn in the ethanol industry.

Ethanol is a clean-burning, high-octane motor fuel that is produced from renewable sources. At its most basic, ethanol is grain alcohol, produced from crops such as corn according to the American Coalition for Ethanol. Corn based ethanol reduces greenhouse gas emissions by 52% when burned, while cellulosic based ethanol reduces greenhouse gas emissions by 82% compared to oil based gasoline, according to the Argonne National Laboratory.

Cellulosic vegetation includes woody grasses like switch grass, miscanthus, and corn husks, as well as hybrid poplar trees. These biomasses require little or no fertilizers or pesticides so less greenhouse gas is emitted while they grow, compared to corn. In addition, cellulosic biomass yields more ethanol per acre per year compared to sugar beets, sugar cane, or corn, according to Charles Stillman of CLEAN Energy.

Biodiesel is a domestic, renewable fuel for diesel engines derived from natural oils like soybean oil, according to the National Biodiesel Board.

By converting from petroleum based diesel to a diesel with 20% biodiesel blended in (B20), it has shown to reduce particulate matter emissions by 10%, carbon monoxide by 11%, carbon dioxide by 15%, and unburned hydrocarbons by 21% according to the DOE.

The EPA is responsible for revising and implementing regulations on the amount of ethanol blended in gasoline. Currently, the EPA is considering an increase of the maximum amount of ethanol allowed to be blended into gasoline from 10% up to 15%. The EPA is slated to give their results of their research on a 5% increase by December 1, 2009. Although EPA Administrator, Lisa Jackson does not think that the EPA will be ready by the December 1 deadline.

Nine billion gallons of ethanol was blended into US gasoline in 2008 according to the EPA. The Renewable Fuel Standard program’s goal is to increase the amount of ethanol to 36 billion gallons by 2022.

Future

Biomass is logical because it is a renewable energy source, and while it often emits greenhouse gasses when used, biomasses absorb greenhouse gasses when they were alive. For example, ethanol production requires fossil fuels and emits greenhouse gasses, but the corn used in production absorbed more greenhouse gas when it was going through photosynthesis in the field. Biomass is a net reducer of greenhouse gasses.

Biomass is fairly cost effective. Direct combustion of biomass produces electricity for about 7 cents per kWh, but can vary considerably according to the DOE. Costs for producing electricity from biomass greatly vary because of many factors, like transportation, technology, or collection of the biomass. Costs are decreasing over time with newer technology. For example, ethanol is going to become cheaper to produce because more efficient enzymes are being used in production, according to the National Renewable Energy Laboratory.

By 2012, biofuels are forecasted to be produced for less than $1.50 per gallon according to the DOE while gasoline prices could double by 2012, according to CIBC World Markets.

The goal of renewable energy is to end dependency on fossil fuels while lowering greenhouse gas levels. Biomass can help by providing a renewable energy source that is readily available in more places than wind, hydro, or solar.

Biomass has great potential. Currently, less than 1% of global farmland is used to grow biofuels crops according to the DOE, while USDA estimates that more than 33% of the U.S. corn crop will be used to produce ethanol by 2010. Farmland demand will increase because of the need for biofuels in the future.

As coal creates 50% of the US energy while producing 90% of CO2 emissions from electricity generation, biomass can be added to coal power plants to help decrease the emissions noted by the Natural Resources Defense Council. Biomass can also help lower CO2 emissions when used on their own, making the world a self-sustaining, cleaner place.

-Colvin