Reporting from Haiti: On the Road to Developing a Wicked Biodigester

I come to you from Cap Haitien, Haiti where we are at work on AIDG- Haiti’s first biodigester. The majority of the biodigesters construction techniques have been developed in Guatemala but are being tried out here to make the technology more appropriate for Haiti.

Right before coming to Haiti, however, I was in Pachalum, Guatemala (Department of Quiche) working on the first of three biodigesters that AIDG is building in the community. AIDG and the municipality of Pachalum have entered into a unique project relationship. AIDG, Pachalum, and the families who will be receiving biodigesters are equally shouldering the costs associated with the project. The owners of the first digester, Don Ramiro and his family, will begin filling it with animal waste created from their pig farm. The Ramiros don’t currently have electricity and are looking forward to the benefits that their biodigester will bring. They are also excited to have one of the first biodigesters in the area.

The pigs on the Ramiro farm are used in the family restaurant, “La Casa de los Chicharonnes”, making the biodigester site long-term stable. A problem that we’ve observed with single family biodigesters is that the owners’ tend to sell off the animals that feed the digester in times of need. Once there is no waste to put in the digester, the system will stop producing gas after about a month. Undigested waste will settle to the bottom of the tank. The loads of settled out waste have to be removed before the digester could be put back on line.

Don Ramiro is less likely to reduce the number of animals he has unless his business closes down. So, we’ll be recommending “La Casa de Los Chicharonnes” to everyone to make sure that it doesn’t close!

Completed Biodigester at Don Ramiro's
Completed Biodigester at Don Ramiro’s

I’m using many of the techniques that were developed in Pachalum here in Haiti as we construct the biodigester. The system is being built at Project Pierre Toussaint, a center for Cap Haitien’s street boys. The center takes in street boys of all ages and shelters them, feeds them and gives them a hands-on practical education. It’s a very inspiring place to work.

After the digester is complete here, I will return to AIDG- Guatemala to finish up the project in Pachalum and build a biodigester for AIDG’s new educational center in Xela. We hope to use some new ideas for this installation that incorporate aspects from both the floating dome and fixed dome designs.

We’ve made multiple improvements to the design over the course of the technology development in Guatemala and Haiti:

  • We are now using a removable wood form for the construction of the concrete biodigester tank. The use of reusable forms is dropping the overall cost of the system and allowing it to be constructed more quickly and with much greater consistency in the shape of the tank. The removable wood form, when assembled looks like a giant wine aging barrel.
  • We are now encapsulating the fiberglass/sheet metal dome in a PVC frame that acts as part of the guide system to ensure the dome floats directly up and down as gas is produced and consumed. The PVC capsule carries all the structural forces so this is also a step in the direction of removing the sheet metal core from the dome. Removing the sheet metal/flat iron core would greatly reduce the overall cost of the system and also remove the potential of problems arising from zinc galvanization leaching into the digester and disrupting the process.
Interior Wood Form being used to Construct the Digester Tank
Interior Wood Form being used to Construct the Digester Tank
The wood form wrapped in HDPE, ready for the exterior form to be placed around it.
The wood form wrapped in HDPE, ready for the exterior form to be placed around it.
Making the concrete digester tank at Project Pierre Toussaint
Making the concrete digester tank at Project Pierre Toussaint

Link of the Day 051908: Is there enough pig manure to feed the world? [Salon]

From Salon’s How the World Works Blog:

“Without chemical fertilizer,” says Norman Borlaug at the very end of a depressing story in Wednesday’s New York Times about rising fertilizer prices, “forget it. The game is over.”

Norman Borlaug is the American scientist widely credited with spearheading the Green Revolution, and his views have been discussed previously in How the World Works. Short version: He believes organic agriculture cannot feed the world, and anyone who thinks so is an idiot. Chemical fertilizer facilitated a 600 percent surge in global food production between 1900 and 2000, allowing the global population to boom from 1.7 billion to 6.5 billion.
There was only one thing missing from the Times story — any kind of a comment from anyone representing the organic, sustainable farming community.

Link of the Day 051708: Hulk smash … inefficiency!

Ed Norton - Hulk smash...inefficiency!

From Gristmill:

Ed Norton will go green — literally — next month when he hits the big screen as The Incredible Hulk. But on Wednesday he was on the Hill talking up the virtues of going green figuratively, in our building practices.

Norton appeared before the House Select Committee for Energy Independence and Global Warming, along with experts in the green-building field, to talk about why building green is better for the planet and your wallet. Norton is a trustee for the Enterprise Foundation, which works to bring green building practices to low-income housing developments.

Hat tip Steph H.

Event: Choose GOOD Farmers Fair June 7 @ 5PM [Solar One, NYC]

I always have a great time at GOOD Magazine events. Here is some green goodness they are putting on in June.

Choose GOOD Farmers Fair
Date: Sat 07 Jun 2008
Time: 05:00PM
Location: Solar One [map], 23rd Street & the East River (2420 FDR Drive, New York, NY 10010) 6 train to 23rd, L train to 1st Ave
RSVP Details: This is a 21+ event and for subscribers only, so please subscribe before you RSVP!

Performers: Jacques Renault, These New Puritans, and David Prince “The Daily Swarm”.


Food. Drinks. Music. Community.

GOOD, Greenmarket, Solar One and JetBlue team up for a day of local farmers market foods and Greenmarket inspired cocktails.

Live bees, mozzarella making, local farmers, bamboo t-shirts, edible seedlings, a photobooth and much more!

Stone Barns, The Tasting Room, The Green Table, The Cleaver Co., Purus, Bluecoat Gin, Flor De Cana, French Rabbit, Red Jacket Orchards, Cereplast, Saxelby, Andrew Cote, Jonathan White, Rick’s Picks, Alive Structures, Media That Matters, LES Ecology Center, NY Sun Works, Transportation Alternatives, Verterra, Tom Cat Bakery, Hope Equity, Greenmarket, CENYC, Solar One and JetBlue

Bike valet provided by Transportation Alternatives.

Recycle with the Lower East Side Ecology Center.