Energy from the Garden to the Kitchen
By Ming Harris-Weidner
Located outside of Can Tho’s center, lies a commune of farmers called My Khanh. A small dirt road, just wide enough for two motorbikes, winds through My Khanh and mirrors the path of the river that provides substance for the farmers living there. Large flowering fruit trees cast a refreshing shade over the soft ground and our group walks excitedly to our set location. As we walk, we wave to farmers and observe their simple, open air dwellings.
Just by looking at the beautiful scenery and friendly faces that inhabit My Khanh, one would never guess that just over 40 years ago, My Khanh was an area of conflict during the American Vietnamese war. A series of changes, both political and economic, have contributed to the adaptive abilities of farmers in the Delta.
One theme that we have come across many times throughout our trip is the issue of providing energy for an ever growing and modernizing population. To combat this problem, farmers in My Khanh have invested in biogas digesters which produce energy through biomass that can be found on their farms.
A popular model in My Khanh is called the VACB model which stands for garden, fish pond, pig raising, and biogas digestion in English. This model is designed to make use of most of the resources on the farm and provide more income for farmers. The system works in a way that everything that the farmer produces can either be sold, or used in another area of the farm.
Our first example of this method was on a farm that used plant biomass to fuel its digesters. The farmer showed us how he used a green plant that grows in his ponds, called elephant ear, to produce methane gas. Along with this plant, he raised fish and snails in the same pond. The fish used the plants as cover and the snails used it as a food source. After the snails and fish grew, the farmer could sell or eat them. The farmer also raised chickens and elegant looking fighting cocks which he said sold well during the new year.
After hearing about how VACB functions on the farm, we got to see the biomass digesters in action. We all watched with curious eyes as the farmer dipped a long-handled net into the water, fishing out the floating green biomass that would soon turn into energy. He then placed the plants into a large blue barrel that slanted upwards out of the ground. Using a long black pole, he pushed the biomass deep into the chamber and sealed the top. The biomass digester’s main job is to facilitate decomposition and fermentation. This process takes place under anaerobic conditions in which anaerobic organisms help break down the biomass. Overtime, methane gas is produced. A small tube transports the methane gas from the digester to the kitchen. Stored gas is kept in large cylinder shaped plastic bags that hang from the ceiling.
Plant matter is not the only biomass that can be used to create methane. On the two other farms we visited, we learned that farmers can also use manure from a variety of animals including pigs and snakes. Experiencing first-hand how innovative and creative these farmers are in making their farms more self-sustainable is inspiring.
With ever changing conditions, both in the environment as well as in the economy, farmers in the Mekong Delta must adapt to survive. The great example we saw today of this adaptation in action, shows me that change can be positive and environmentally friendly.