Plants could soon provide our electricity. In a small way they already are doing in research laboratories and greenhouses at project Plant-e, a university and commercially-sponsored research group at Wageningen University in the Netherlands,
The Plant-Microbial Fuel Cell can generate electricity from the natural interaction between plant roots and soil bacteria.
It works by taking advantage of the up to 70 percent of organic material produced via photosynthesis that cannot 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 research team, led by Marjolein Helder, is able to generate electricity.
“Solar panels are making more energy per square metre but we expect to reduce the costs of our system technology in the future. And our system can be used for different applications,” said Helder.
Plant-Microbial Fuel Cells can be used on various scales. An experimental 15 square metre model can produce enough energy to power a computer notebook. Plant-e is working on a system for large-scale electricity production in existing green areas like wetlands and rice paddy fields.
“Our system can be used for different applications. Our technology is making electricity but also could be used as roof insulation or as a water collector. On a bigger scale it’s possible to produce rice and electricity at the same time and in that way to combine food and energy production,” claimed Helder.
A first prototype of a green electricity roof has been installed on one building at Wageningen University and researchers are keeping a close eye on what is growing there. The first field-pilots will be started in 2014.
The technology was patented in 2007. After five years of lab research, Plant-e is now taking the first steps toward commercialising the technology
In the future, bio-electricity from plants could produce as much as 3.2 watts per square metre of plant growth.