For people living in some remote villages in Indonesia, heating houses and fuelling stoves can be a real challenge. The resources required, like gas and wood, have to get shipped in and distributed to individual households, and not only does this process take a whole lot of time - some families wait weeks for new gas to arrive - it also produces a tonne of emissions¹ that contribute to global warming.

 

在印度尼西亚的一些偏远小村庄中，房屋取暖和锅炉燃料是个大问题。像天然气、木头之类的资源需要从外面运输进来，然后再分配到每个家庭。这个过程很漫长，许多家庭要等好几周，而且这些燃料会产生大量的二氧化碳，加剧全球变暖。

 

The good news is that this antiquated² system is now on its way out, thanks to an unlikely source: tofu.

 

Now, thanks to a government-run program, the waste water from all that tofu production is getting transformed into biogas that can be pumped directly to houses.

 

But how does it work?

 

First, let's talk about tofu. Tofu has been made the same way for generations, and it's a rather simple, yet time-consuming process.

 

Basically, producers start by soaking and grinding soybeans to separate the soy milk from the soy pulp³. This step takes the longest because the beans have to soak for hours before they are ready for separation.

 

After the separated parts go through a filtration system, the protein and oil are separated from the soy milk. A chemical coagulant⁴ is added to firm everything up. Once formed, you have tofu ready for cutting. So, in essence, tofu is coagulated soy milk that you can pick up and eat.

 

Though simple in practice, an enormous amount of water is required to make tofu - roughly 33 litres for every kilogram of spongy bean curd⁵.

 

Researchers found that this waste water could be turned into biogas if a certain type of bacteria is added to it.

 

Every day, the waste water is collected from various shops and treated with bacteria. Once transformed, the gas is pumped directly to local homes.

 

Besides creating a green energy source for locals, using all that waste water has significantly helped the local environment. Thousands of litres of waste water drained from raw tofu was once pumped daily from factories around the village into nearby rivers, befouling waterways and contaminating rice fields downstream.

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