Electricity From Living Plants

A Dutch start-up called Plant-e has developed a way to use living plants as a continuous source of clean energy – all that’s needed is a source of light, carbon dioxide, water, and a field or patch of plants. The system works best in wetlands or watery fields like rice paddies, and the quality of water doesn’t matter, so areas unsuitable for growing crops could be repurposed as a power source. There’s no complicated infrastructure to install, which makes it easy to bring electricity to isolated regions that are currently without power.

The theory behind the Plant-e system is surprisingly simple. When plants create food using photosynthesis, a large portion of the organic matter generated is excreted by the roots into the soil. That organic matter gets munched on by microorganisms living in the soil, which release electrons as a byproduct of this consumption. By placing an electrode near the roots, it’s easy to harvest this energy and turn it into electricity.

The process is similar to elementary school science projects that created a battery out of an apple or potato, and leaves the plants completely unharmed by the process. Tests have shown that the plants will continue to grow normally in the presence of electrodes.

A prototype green roof using this technology is already being tested in the Netherlands. Currently, the Plant-e team is able to generate enough energy to power a cell phone, but the hope is that soon this method will be able to harvest a significant amount of electricity — maybe even enough to power a house.

See www.plant-e.com for more information.