I am an environmental educator at the Ecovillage Training Center at The Farm community in Summertown,Tennessee and author of Shutdown: Nuclear Power on Trial (1979); Climate in Crisis: The Greenhouse Effect and What We Can Do (1990), and most recently, The Post-Petroleum Survival Guide and Cookbook: Recipes for Changing Times, from New Society Publishers and Amazon.
Arriving in Sao Paulo, Brazil for the International Permaculture Conference in 2007, I checked the online schedule and saw that the organizers had set me down for a morning session on "making money from tree planting." Caught by surprise, I had to scramble to prepare a powerpoint and one of the ideas I thought to explore was biofuels. Conventional wisdom has it that "agrifuels" are in competition with food production and climate remediation. I dashed off an email to David Blume asking for an example of "permaculture fuels."
He replied, "Well to take a page from the book. In semiarid areas where the temperature goes no lower than 0 degrees F you can plant an overstory of mesquite to provide both 340 gallons of alcohol per acre from the pods and fuel the plant with coppiced branches from the tree. In the understory you plant perennial Opuntia (nopales) thornless cactus, and between there and the dripline and beyond you plant the starchy root crop, Buffalo Gourd, for a total yield of far over 1000 gallons per acre without irrigation."
There you have it, a polyculture for food and fuel. But what about climate change? I wrote him back, "Would you say the guild above is a net carbon sink?"
He responded, "It is absolutely a massive carbon sink. Pretty much all arid country crops put the majority of their growth underground and have a robust mycorhyzzal feeding regime. Perhaps 80+% of carbon produced in the top growth is exuded for rhizosphere associates. Mesquite is unique in that a large portion of its root burrows deep to support it with water extracted from far below. There have been recorded instances of mesquite going down 160 feet for water."
And that, in a nutshell, is Farmer Dave's permafuel thesis. That he takes several hundred pages to flesh it out, in Alcohol Can Be a Gas! Fueling an Ethanol Revolution for the 21st Century, is an enduring blessing for permaculturists everywhere. This six-volume set, bound into one thick paperback, is both required reading and a standard reference on a par with A Pattern Language and David Jacke's Edible Forest Gardens.
The six books contained in one are, in order, Understanding Alcohol: Visions and Solutions (including "busting the myths," polyculture and photosaturation, and Brazil's national program dissected), Making Alcohol: How to Do It (including 30 odd feedstocks from algae to whey, the sugar method, the starch method, fungal and bacterial enzymes, fuels, and distiller construction), Co-Products from Making Alcohol (animals, aquaculture, mariculture, mushrooms, methane, etc.), Using Alcohol as Fuel (carburetion, injection, small engines, flex-fuel conversions and cogeneration of heating, lighting and cooling, and typical conversions), The Business of Alcohol: Hands-On Advice (legal and economic considerations and case studies); and A Vision for the Nation (state and federal incentives, Community Supported Energy and permaculture).
Just exactly what is the appropriate role for alcohol fuels is an old, but ongoing discussion, and it has been known to get heated at times. The Tortilla Rebellion in Mexico, catastrophic overplanting of maize and soya, gene splicing by multinationals for cellulosic substrate alchemy, forest clearing worldwide -- these are serious concerns.
Recently, the U.S. Senate passed legislation to increase ethanol production by giving generous subsidies to the U.S. farm belt. The Act mandates the use of 15 billion gallons of biofuels annually by 2015 and 36 billion gallons by 2022 (up from 8.5 billion subsidized gallons now). Nearly all of this would be corn ethanol, taken from grain stocks, with the stover burned or plowed in. Beginning in 2016, the government would ask farmers to add the corn stover, along with switch grass or wood chips, to make annual increases of 3 billion gallons in "cellulosic" ethanol. This legislation passed over the opposition from Big Oil and food manufacturers, but is just the kind of massively soil-destroying, economically bankrupting, petro-addicted type of legislation that was ideal for harvesting votes in the Iowa caucuses.
By showing how ethanol can be ethically produced in combination with food, soil, carbon sequestration and other objectives for healthy system design, Blume provides a rescue remedy for our planet at a time when it could scarcely be needed more.
Loek Boonkamp, who studies agricultural trade and markets for the Organization for Economic Cooperation and Development, estimates replacing just 10 percent of the world's current petroleum use with biofuels would consume about 30 percent of all the grain, oilseed and sugar produced in the U.S., Canada, the European Union and Brazil, not to mention a huge volume of water. Blume takes Boonkamp's argument head-on.
The US has 1500 million acres of agricultural land and uses 70 million -- about 5 percent -- for corn. Mesquite covers 70 million acres of desert land. Harvesting mesquite pods would yield more alcohol than corn without any inputs of soil, fertilizer or water. The US could achieve similar yields from the lawn clippings coming off suburbia on any given Saturday (30 million acres at last count). There are dozens of these examples in the book. Moreover, one has to consider how much of that corn produced in the US is actually used as a food, and how much is used in floor wax, plywood, crayons and other products.
But then, why use farmland at all? Why not harvest ethanol from cattails or dried seaweed? Willows and bamboo planted on berms separating long canals of cattails, with greywater, spent mash and fermentation carbon dioxide returned to the roots could yield 10,000 gallons of ethanol per acre.
The Chinese are getting 4.8 dry tons per acre off seaweed from coastal waters, and the Vietnamese, who farm shrimp from April to September, harvest algae from the same shallow lagoons and estuaries the rest of the year. Kelp grown on nets can cover hundreds of acres of ocean and provide bread flours, carrageenan, agar and other ethanol co-products while also restoring health to over-nitrified "dead zones." Blume estimates the energy return on marine ethanol is on the order of 15 to 1, significantly better than current returns on petroleum exploration and production.
Alcohol Can Be A Gas! goes beyond helping the mechanically adept convert their internal combustion engines to ethical fuels. It provides clear operating manuals for the farmers who will grow those fuels, the fermenters who will build and operate the stills, and the artisans who will create and trade myriad co-products.