Imagine: no more having to work in a hot stuffy office in summer. Instead you can enjoy fresh country air wherever you like. No more hassle if the batteries in your phone or other electronic equipment run low, you can charge them in any field or garden. Nonsense? Not according to recent research by Marjolein Helder and David Strik at the WUR (University of Wageningen, NL). They discovered that you can generated energy from the natural interaction that occurs in the soil of practically every garden. Their company Plante-e has developed a fuel cell which does just that.

It has been named Plant-Microbial Fuel Cell and they will continue to develop it further. The fuel cell draws energy from the natural interaction between living plant roots and soil bacteria.

How does the Plant-Microbial Fuel Cell work?

Marjolein Helder explains: “Put simply, we ‘capture’ the electrons in the ground and convert them to electricity. We do this with a so-called plant-microbial fuel cell which transports electrons from one pole to the other. And electrons flowing through a wire ‘generate’ electricity which could power a light, for example.”

Plants produce organic materials via photosynthesis. The roots excrete up to 70% of this material (unused) into the soil. Soil bacteria break this down into organic residue. This degradation of the bacteria releases electrons. The electrons generate energy which the researchers then capture.

Plant-e: living plants generate electricity 

Possible applications

The Plant-Microbial Fuel Cells currently generate more watts per square metre of plant growth than is generated by fermenting biomass. This is expected to rise in future, producing up to 3.2 watts per square metre of plant growth. If that happens, a household with an average annual consumption of 2800 kWh could be powered entirely by bio-electricity from plants. All this would require is a suitable roof of 100 m2.

Another positive aspect of this new technology is that it causes no nuisance to anyone. It doesn’t pollute the horizon, nor does precious nature or agricultural land need to be sacrificed. In fact, this discovery by Helder and Strik actually combines these two elements.

Further development needed

Not all the possibilities have been identified yet, by any means. What would the price of this electricity be, exactly? And which plants are most suitable? Marjolein Helder and David Strik have already asked themselves the same questions but answering them requires more research.

The Wageningen-based company has been awarded the Pre-Seed Grant of €250,000. This money will enable the two researchers to further develop their ideas. They have already found a suitable location: the experimental roof of the NIOO-KNAW (the WUR Institute for Ecology). This promising invention will be further developed from there.