Katrin Puetz saw the potential of biogas for rural communities while doing her master’s thesis at a university in Germany. She wondered how to do the “last mile” of distribution from a central digester site to someone’s home. She came up with the biogas “backpack” — a sturdy bag to transport the gas.
Since then, she’s created a full line of products for villages to use biogas locally. First there’s a 2 x 5 meter bio-digester “system” for 44 pounds of cow dung a day. It’s a tank with an outer tent covering. Then, there are the packs which hold 1.2 cubic meters of biogas at a time (6 kilowatt-hours of energy or enough for four hours of cooking). And there’s a simple stove and several other parts.
The bag has a valve that attaches to the stove with a hose. Villagers place a rock or plank of wood on top of the bag to push the gas out. The bag presents no explosion risk because it is isn’t pressurized, Puetz says. “You can put the bag on an open fire and it will take 15 to 20 seconds to even melt the material. It is a very heavy duty material. And even after you’ve melted a hole the gas will come out and slowly flare off, because biogas needs to be mixed with air to be flammable,” she assures us.
Read more at Co.EXIST: These hilarious inflated backpacks are actually delivering cheap local energy to the rural poor. Picture: (B)energy. Previously: Gas Bag Vehicles.