Food waste is one of the biggest sources of trash in the United States — with as much as 50 percent of all food thrown out, it accounts for around 15 percent of the total municipal waste stream. The food doesn’t just fill landfills, it also contributes to global warming; decaying food is a major source of methane, a potent greenhouse gas (the global warming potential of methane is 21 times larger than carbon dioxide). Now some cities are beginning to capture that waste to create energy. The latest is Portland, Ore., which will soon have a new waste-to-energy facility.

Columbia Biogas will convert commercial food waste to energy at its plant in Northwest Portland, and deliver the power to PacifiCorp, an electricity provider. The companies believe the plant will be the first in the U.S. to generate energy from food waste from within an urban industrial setting.

Using anaerobic digestion in sealed tanks, Columbia will capture enough biogas to generate 3 megawatts of electric power — enough to power 3,000 typical homes. Eventually, production is expected to reach as much as 5 megawatts.

The facility will collect food waste from grocery stores, restaurants, industrial food processors and other businesses. It can also recover liquid waste including oils and grease. The plant’s location near Portland businesses will also reduce hauling costs and save businesses time.

In addition to electricity, Columbia Biogas will create fertilizer and other products from the food waste. The processing also creates waste heat, which will be captured and used by the plant. The facility will also use a multi-stage filtration process to recycle water from the waste.

Main photo credit: sporkist/Flickr