Dear EarthTalk: Is there a way to utilize the energy in my dogs’ poop? I have three dogs and lots of poop and would like to dispose of it in a “greener” manner. -- Mary C., Wallace, ID
No doubt creating a way to do so is possible, as large systems called anaerobic digesters (or biogas digesters) are often used in landfills to wring energy out of trash, as well as on some big farms and ranches where large amounts of cow manure provide plenty of feedstock. In such systems microbes generate methane gas—which can be captured and used for power—once they are set free on manure or trash. The economics of putting biogas digesters in landfills or big cattle operations can make the up-front expense tolerable—money can be made or saved by selling or utilizing the resulting power—but doing so in one’s back yard might be a different story.
Not to say it can’t be done: This past September artist Matthew Mazzotta, armed with a $4,000 grant from the Massachusetts Institute of Technology (MIT)—where he earned a master's degree in visual studies last year—created the ingenious Park Spark poop converter system that uses dog poop to power a gas lantern that illuminates a corner of the Pacific Street Dog Park in Cambridge, Massachusetts.
The system uses two steel, 500-gallon oil tanks, connected by diagonal black piping and attached to an old gaslight
"Matthew Mazzotta, armed with a $4,000 grant from
-style street lantern. “After the dogs do their business, signs on the tanks instruct owners to use biodegradable bags supplied on site to pick up the poop and deposit it into the left tank,” reports Jay Lindsay on the Huffington Post. “People then turn a wheel to stir its insides, which contain waste and water. Microbes in the waste give off methane, an odorless gas that is fed through the tanks to the lamp and burned off.” Although the park is small, neighborhood dog owners have provided enough waste for a steady supply of fuel.
The 33-year old Mazzotta got the idea after travelling in India and seeing people there using poop in small “methane digesters” to cook food. When he visited Pacific Street Park with a friend in 2009 and saw the park’s trash can filled with bags of dog poop, the Park Spark idea was born. He hopes the installation, which was dismantled after its one-month run, has helped point out to people that there are potential energy sources all around us, and that we must consider every option at our disposal, so to speak, as we wean ourselves off oil in the face of impending climate change.
Besides reducing waste going to landfills, another environmental benefit of utilizing dog poop for energy is reducing one’s carbon footprint. Burning methane derived from dog poop or other biodegradable waste material in an anaerobic digester is carbon neutral, meaning it doesn’t contribute any new greenhouse gases into the atmosphere that could exacerbate global warming.
While it might not be worth $4,000 or a degree from MIT for you to create your own version of the Park Spark in your backyard, it’s good to know that such technology exists, and will no doubt someday be available and affordable for the rest of us as long as we continue to show find ways to reduce, reuse and recycle everything we possibly can.
From the Editors of E/The Environmental Magazine
Dear EarthTalk: Are there efforts to increase bike lanes and paths around the nation? I’d like to be able to bike more instead of drive, but I’m concerned about safety. -- John Shields, Minneapolis, MN
|"Around the U.S. new bike lanes and paths are all the
rage, helping cash-strapped cities simultaneously green
operations and trim budgets (adding bike lanes is far
less costly than building new roads). Some studies have
even shown that bike trails help improve nearby home
values. Pictured: a bike Lane on First Avenue in New
York City.”Credit this image to "Joe S., courtesy Flickr."
Around the U.S. new bike lanes and paths are all the rage, helping cash-strapped cities simultaneously green operations and trim budgets—adding bike lanes is far less costly (to taxpayers and the environment) than building new roads. Also, the nonprofit League of American Bicyclists reports that real estate values increase with proximity to bike paths. “People enjoy living close to bike paths and are willing to pay more for an otherwise comparable house to be closer to one,” the group reports, citing examples from Indiana, California and elsewhere showing that homes near bike trails command a premium upwards of 10 percent.
In New York City, bicycling is the fastest growing mode of transportation. A 2006 citywide mandate has led to the laying down of some 200 miles of new bike paths recently. Also, the area around Madison Square in midtown is now bike-friendly; seven blocks of Broadway now feature green-painted bike lanes between the curb and the parking lane to provide cyclists with a buffer against rushing motorized traffic.
In September, central Tennessee (Nashville and environs) adopted an ambitious plan to add upwards of 1,000 miles of bike paths (also 750 miles of sidewalks) across seven counties, a scheme that won the “best project” award from the Institute of Transportation Engineers. Nashville itself will increase alternative transportation spending from 0.5 percent to 15 percent of its transportation budget, and hopes to reduce traffic congestion and obesity—Tennessee has the nation’s second highest rate of obesity—in the process.
Portland, Oregon, long a leading U.S. city on environmental policy, has allocated over $20 million over the last few years for bicycle infrastructure improvements, and plans to spend another $24 million upgrading the city’s network of bike paths and trails. One of the city’s latest innovations has been to convert two parking spaces on city streets to bike corrals capable of holding two dozen bicycles. In addition the Bike Portland blog reports that the city now supports some 125 bike related businesses, mostly small and locally owned, covering everything from custom bike building to accessories and repair.
In Davis, California, named America’s top cycling city by the League of American Bicyclists, bikes outnumber cars and bike paths occupy 95 percent of arterial and collector roads there. Some 14 percent of all commuters in Davis commute to work by bike, which is 35 times the national average. Other cities in the League’s Top 10 include Palo Alto and San Francisco in California; Corvallis, Portland and Eugene in Oregon; Boulder, Colorado; Madison, Wisconsin; Tucson, Arizona; and Seattle, Washington.
Some cities—New York, Los Angeles, Seattle—make available maps of bicycle routes. The inclusion of bike routes on Google Maps has also been a boon to cyclists across the country looking for the safest and most direct routes. Users can click on a bicycle icon after hitting “Get Directions.” Local bicycle clubs are a good place to turn to find the best bike-friendly routes though your region; The A1 Trails website provides a comprehensive list of bike clubs and other resources around the U.S. and Canada. With so many tools and new infrastructure, it might be high time to leave the car parked and hop on your bicycle.
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