An Indonesian village has found a way to turn the waste from tofu into bio gas, saving money and cutting down on pollution.
Waste water from the soybean used in tofu production is collected in tanks and undergoes a natural fermentation process.
The bio gas generated in the treatment facility then flows into pipes connected to two tofu factories and 20 households.
The villagers use the bio gas for free, which saves on the cost of kerosene.
The natural fermentation process also frees the waste water from polluting substances that used to flow into the local river.
Indonesia hopes to expand the simple process across the country, where many tofu factories dispose waste water without treatment.