When I set out to write a story about the energy possibilities of garbage, portrayed as nothing but a sci-fi gag in the movie Back to the Future Part II, I knew I had to check in with National Geographic Emerging Explorer T.H. Culhane. (See related, “Four Energy Ideas ‘Back to the Future’ Got (Almost) Right.”)
Year after year, Culhane has been one of the most riveting storytellers of the extended Explorer family that National Geographic Society brings together at its Washington, D.C. headquarters each June. You’ll become a believer if you spend time listening to T.H. extol the little-known virtues of in-sink garbage disposals, or show photos of renewable energy outposts he’s catalogued in Nepal. (See related, “On Mount Everest, Seeking Biogas Energy in a Mountain of Waste.)
Even if you spend most of your day reporting and writing on the stymied global effort to grapple with climate change, you’ll be filled with hope after Culhane spills some crumpled cans and foil scrap and tangle of wires on your desk, and demonstrates how junk like this could light a village. (See “How Aluminum Cans Can Power a Village.”)
One of Culhane’s passions has been making methane fuel from garbage and other waste through the process of anaerobic digestion. No, you don’t need fusion as Doc Brown used in the Back to the Future movies. All you need is the right set-up with well-understood technology, and the kind of ubiquitous micro-organisms that have been among the earliest living “bugs” on Earth.
Culhane’s nonprofit, Solar CITIES, has installed biogas digesters from Brazil to the Philippines, with Cairo and Baghdad in between. (See related, “Iraq’s Green Zone Gets Greener With Biogas,” and “Cairo Slums Get Energy Makeover.”)
Recently, Culhane has been working closer to home. An email reached him at a New Jersey port where he and colleagues were taking delivery of biogas digester parts from the Chinese firm, Puxin. They packed them into a “rickety cow trailer” and drove them to a family farm west of Philadelphia, where they’re launching a holiday drive to install food-waste-to-fuel tech in homes and communities. (Here’s a longish video on what they’re up to:)
Culhane said those eager to try small biogas systems include environmentalists, homesteaders, members of Pennsylvania’s simple-living Amish religious fellowship, Native American reservations, and “preppers.” (See related National Geographic Channel show, “Doomsday Preppers.”)
Devastating power outages after 2012’s Hurricane Sandy inspired Culhane and his environmental science students at Mercy College, just north of New York City, to work on home biogas systems for disaster preparedness. (See related, “Can Hurricane Sandy Shed Light on Curbing Power Outages?” and “After Hurricane Sandy, Need for Backup Power Hits Home.”) He and the students cooked “bacon from biogas” at events for prospective students to prove the system’s utility.
And Culhane and colleagues have installed an even more complex test system in the basement of the Hudson River-valley home of feminist-environmentalist Abby Rockefeller. (Great-granddaughter of Standard Oil founder John D. Rockefeller, she is a composting pioneer and her son, Chris Lindstrom, works on Culhane’s team.)
Since biogas cuts food waste, landfill emissions of the potent greenhouse gas methane, and provides home-grown local renewable energy, it seems crazy we don’t use it more often. But in one of the realities that can be depressing to anyone who spends time studying climate change and potential solutions, spending extra time and money on biogas doesn’t seem to make economic sense for most cities and governments as long as they can rely on cheap fossil fuel and landfilling of waste.
That gets me thinking of how much more we could be doing if we had a carbon tax or some other price on dirty fuel and waste, which becomes even more depressing, given the dim prospects in Congress or the international realm for doing anything to hike the price of the fossil fuels that still power our economic engines.
But Culhane says he and his colleagues are undaunted. They’ve “hacked” ways of making biogas garbage-to-energy systems more economical, even when competing against cheap and more abundant U.S. fossil fuel.
Their most exciting innovation is the use of the liquid bioslurry that the biogas system produces as a by-product. They use it as a compost tea, a liquid fertilizer for our vertical hydroponic tower gardens.
“Most people who have heard of hydroponics or aeroponics know that you can grow food reliably without any soil at all,” Culhane said in an email. “But the cost barrier for hydroponics systems has normally been that you have to buy the liquid nutrients to put in the systems to grow the plants and that gets really expensive, so hydroponics are mostly considered a bourgeois solution inappropriate for the world’s poor.
“We are showing, however, that the liquid that comes out of our ‘food-waste-to-fuel-and-fertilizer’ biogas system is perfect for growing nutritious fruits and vegetables, so we NEVER need to buy anything,” he continues.
Culhane actually looks at the trend toward cheap fossil fuel natural gas as a good thing, because it will begin moving people toward methane as a fuel. And then it’s only another step to make the move to renewable biogas. “It is the easiest, safest, cleanest way to get rid of your organic garbage and the best way to do composting,” Culhane said in an email. “Once enough people discover it, it will be unstoppable. They can’t hide the simplicity and profound benefits of the food-waste-to-fuel-and-fertilizer solution forever, can they?” (Listen to “National Geographic Weekend: Creating Electricity From Food Waste, Arresting Poachers, and More.“)