Science

Plant-Microbial Fuel Cell generates electricity from living plants

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The Plant-Microbial Fuel Cell technology is being demonstrated at the Netherlands Institute of Ecology (NIOO-KNAW)
The Plant-Microbial Fuel Cell technology is being demonstrated at the Netherlands Institute of Ecology (NIOO-KNAW)
The Plant-Microbial Fuel Cell generates electricity from organic matter excreted from the roots of living plants

Wetlands are estimated to account for around six percent of the earth’s surface and a new Plant-Microbial Fuel Cell technology developed at Wageningen University & Research in The Netherlands could see some of these areas become a viable source of renewable energy. More than that, the developers believe that their technology could be used to supply electricity to remote communities and in green roofs to supply electricity to households.

Unlike biogas, which is produced by the anaerobic digestion or fermentation of biomass, the Plant-Microbial Fuel Cell generates electricity while the plants continue to grow. Importantly, the researchers say the system doesn’t affect the plant’s growth of harm its environment.

It works by taking advantage of the up to 70 percent of organic material produced via photosynthesis that can’t be used by the plant and is excreted through the roots. As naturally occurring bacteria around the roots break down this organic residue, electrons are released as a waste product. By placing an electrode close to the bacteria to absorb these electrons, the Wageningen UR research team, led by Marjolein Helder, was able to generate electricity.

The Plant-Microbial Fuel Cell generates electricity from organic matter excreted from the roots of living plants

Although the Plant-Microbial Fuel Cell currently only generates 0.4 W per square meter of plant growth, the researchers claim this is more than is generated by fermenting biomass. They also say that future systems could generate as much as 3.2 W per square meter, which would allow a roof measuring 100 m2 to supply electricity to a house with an average consumption of 2,800 kWh a year.

The researchers think such green energy-producing roofs could become a reality in the next few years, with larger-scale electricity production in marshlands around the world following after 2015. The technology works with various types of plants, including grasses such as common cordgrass, and rice, and produces a low-voltage direct current, which can be directly used to charge batteries and power LEDs.

However, the researchers admit the technology still needs improvement in terms of sustainability and in finding ways to limit the amount of material used by the electrodes. Despite these hurdles, they claim the Plant-Microbial Fuel Cell already rivals the economic viability of solar panels in remote areas.

Helder and David Strik, who carried out the first tests of the system, have established a spin-off company called Plant-e to commercialize the technology and expect to have the first products on the market next year.

Source: Wageningen UR and Plant-e

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11 comments
Toffe Carling
Yea, super good idea. But how can 3.4w/sqr meter rival the fact that solar panels get about 240w/sqr meter? The sun gives us 800w/sqr meter. But still a good idea to get power from what´s there already.
Dan Vasii
@Toffe Kaal Maybe the cost per watt is equivalent.
Joel Detrow
So we can potentially plant wetlands that generate electricity? I can see the conversation 20 years from now: "Well, nice knowing you, New Orleans, but we gotta put the wetland back..."
Slowburn
What effect does the day night cycle have on electrical output?
Joseph Mertens
Well I think the Day Night cycle would have little effect as the power is generated below ground by bacteria who have a surplus of food to last the night and longer as their growth can out last the plants life by wide margins. I think this is a great Idea and New Orleans will be done next hurricane like it or not Nature doesn't need permission.
jochair
I sure hope those guys in Wageningen got it right. and that it works for many plant species; imagine you stick one end of an electric cable in the bank of the Amazon river, than take the other end across the rain forest and light a bulb there by touching a root. you could get electrocuted too, how exciting.
Siegfried Gust
"70 percent of organic material produced via photosynthesis that can’t be used by the plant and is excreted through the roots." Can that be true? I have a hard time believing even 10% of that.
Mitra Ardron
Interesting - so lets do the numbers ... If they achieve their maximum of 3.2W/m2 (8x their current output) a 100m2 system would generate 2.8kW per year, or about equivalent to a 1.7kW system covering maybe 9m2 and costing $3500 (for panels & frames), both systems would need batteries/inverter/grid-tie etc. Sounds ambitious if they could achieve this at $35/m2 especially given the likely high cost of the electrodes.
Kwazai
so how big does the anode and cathode have to be? G90 galvanized sheet work? maybe a slightly acidic hydroponic roof? or would a base aquaponics solution work? great big 'ground' battery dry cell would be carbon /zinc?
Gargamoth
Mercedes Biome is one step closer to being a reality just apply this tech to the car bulb to be grown