Electricity from the soil (Spain) 

It is hard not to be amazed by revolutionary ideas.

We know that it is possible to create electricity from fruit and veg, even though it takes a considerable quantity of, say, oranges, to power a small lamp. But to take a pot of earth covered with grass or plants and be able to turn a circuit on and off by touching it … well, it just doesn’t seem possible.

And yet … this is what the Spanish firm Bioo has done. Starting from the principle that biotechnologies can be used to find innovative solutions, they have developed sensors (in a project financed by the European Commission) to create precision agriculture that is capable of producing energy from the soil by using its bacteria and vegetation. In this way they have created a bioreactor that is capable of “extracting” energy directly from the soil.

A “box” of soil with its vegetation, 10cm height – 20 cm depth, can produce 100ms 28W discharge/day. Every discharge is automatically re-charged by the soil every 24h in-field.

This happens independently of humidity, temperature and pH, and even the wireless communication system. Put simply, this technology provides a biological battery fed by the soil. That is possible thanks to the Bioo’s microbial fuel cell, powered by organic matter and fertilizers.

So in practice: if we have in our homes a plant pot full of soil, 40 by 40 cm and 25 cm deep, we get an Energy Output 20Wh/year per m².

As well as being interesting from the scientific point of view, the project is important for its technical and commercial approach. The 9 research groups that developed the bioreactor and the related technology have not sought to protect their invention; rather, they are open to further developments and applications. The project has already been awarded recognition and prizes at both the European and international levels.