Eat your leftovers

Americans throw away about 30% of all food produced domestically each year, and since at least 8% of the U.S. energy budget goes towards bringing food to tables across the country, energy waste is closely tied to food waste [1]. In fact, all of that wasted food equates to about 350 million barrels of oil per year [1].

The energy embedded in food waste comes from many sectors of the food industry: production, transportation, storage, and preparation. Since food waste is a cultural problem, it is not likely that it will stop any time soon. A better solution to waste prevention could be to take advantage of the energy potential of food in our landfills. Rather than sitting in a landfill, organic wastes such as food leftovers are put into anaerobic digesters that produce biogas rich in methane [2]. This biogas can be used as fuel for heat and power generation, and the stuff that’s leftover can be used as composting material [3].

But how useful is this biogas? The EPA estimates that “if 50% of the food waste generated each year in the U.S. was anaerobically digested, enough electricity would be generated to power 2.5 million homes for a year” [3]. What kind of power does that translate to? From a study conducted by the EPA regarding production of biogas rich in methane from anaerobic digestion food waste, anywhere from 730 to 1300 kWh can be harnessed per dry ton of food waste [3].

Since food waste and the push by the federal government via mandates and subsidies to increase the production of biofuels in general are here to stay, biogas produced through anaerobic digestion of food waste may become a larger part of the overall fuel mix for electricity.

References

[1] Cockrell School of Engineering (n.d.). Wasting Food Means Wasting Energy. Retrieved from   http://www.engr.utexas.edu/features/research/wastedfood

[2] International Energy Agency (2007, January). Biomass for Power Generation and CHP. Retrieved  from http://www.iea.org/techno/essentials3.pdf

[3] United States Environmental Protection Agency (2013, February 19). Anaerobic Digestion.   Retrieved from http://www.epa.gov/foodrecovery/fd-anaerobic.htm

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3 Comments

Filed under biofuel, energy

3 responses to “Eat your leftovers

  1. This is a pretty interesting idea. I like the prospect of making use of waste to produce energy, but there has to be a catch, or I feel like we’d already be doing this by now. There’s probably lots of costs associated with this anaerobic digestion process. Still, this idea could potentially put back a lot of the energy that we are currently loosing due to food waste. I agree with you that because wasting food is such an ingrained part of culture, it may be hard to save energy that way. Maybe once we work through all of the requirements for this anaerobic digestion process, it could be a viable option for helping reduce energy waste.

  2. Reblogged this on BioEnergy Consult Blog and commented:
    Rather than sitting in a landfill, organic wastes such as food leftovers are put into anaerobic digesters that produce biogas rich in methane. This biogas can be used as fuel for heat and power generation, and the stuff that’s leftover can be used as composting material.

  3. Leftovers are a challenge in any kitchen and, while I support the use of food waste already heading to a landfill to be diverted to a source, I’d prefer to see the stuff that makes our food stay a part of the ecosystem rather than be burn up. If we just learned to consume only what we need, I doubt we’d use so much energy producing the food we ultimate waste.

    Does this make any sense?

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