Sustainable Energy

“Plant Lamps” Turn Dirt and Vegetation into a Power Source

Researchers in Peru have a new way to capture electricity from plants and bacteria to help rainforest communities.

Nov 23, 2015

Researchers at the Universidad de Ingeniería y Tecnología (UTEC) have developed a technique for capturing the electricity emitted from plants. Actually, to be fair, it’s Geobacter— a genus of bacteria that live in the soil — that do the grunt work. Robby Berman at Slate explains the process:

A lamp powered by microorganisms in dirt.

“[N]utrients in plants encounter microorganisms called ‘geobacters’ in the dirt, and that process releases electrons that electrodes in the dirt can capture. A grid of these electrodes can transfer the electrons into a standard battery.”

UTEC has partnered with global ad agency FCB to produce 10 prototypes and distribute them to houses in the rainforest village of Nuevo Saposoa. Each contains an electrode grid buried in dirt, in which a single plant grows. The grid connects to a battery, which powers a large LED lamp attached to an adjustable arm on the outside of the box. The UTEC video below shows the boxes in action (including a money shot of a lamp being triumphantly turned on):

For Nuevo Saposoa and other underserved communities, this is more than just a crackerjack bit of biological engineering. Electricity, and lighting in particular, are a very real need. Berman writes:

“In the rainforest villages of Nuevo Saposoa and Pucallpa in Perù, there’s an existing electrical grid, but since a flood last March damaged its cables, it hasn’t been working. Forty-two percent of the communities in the rainforest don’t have even that much. Sundown means lights out, a real problem for families with small children—and for students who need to study—unless they resort to unhealthy and dangerous kerosene lamps.”

UTEC has a tradition of this sort of humanitarian innovation, Berman explains. “A while back, it found a way of growing plants on platforms using clean moisture pulled from the air in a region whose groundwater—and ground—has been ruined by pollution.”

If the “plant lamps” (that’s UTEC’s name, not mine) are successful, their appeal isn’t going to be limited to rainforest communities. Who wouldn’t want a houseplant that cut back on their electric bill? Add a bit of green to your bank account and your bedroom.

It’s worth noting that UTEC’s researchers are hardly the first to make use of Geobacter — they’re some of biotech’s most talented microbes. In 2009 Time named the “electric microbe” one of its 50 best inventions of the year. Recent research confirms they’re electrically conductive to boot, which means in theory they can act like nanowires for transmitting electricity. In addition to power generation, Geobacter have also garnered attention for their ability to metabolize pollution like radioactive material.

As elegant as the plant lamps are, it’s easy to imagine even bigger and better applications. What sort of power could an entire garden generate? Is there a way to combine pollution-tolerant plants with the electric grid and bacteria — might a grove of trees help reduce soil pollution and provide power?

Moving forward, it strikes me that ethos of the “plant lamp” is the perfect balm for those of us chafing at the more aggressively capitalistic and controlling approach of the Big Bads of biotech (i.e. Monsanto). UTEC’s plant lamps are an example of using technology to bring people into more mutually beneficial relationships with biology and to solve local problems. It’s symbiosis.