Preventing forest fires with tree power: Sensor system runs on electricity generated by trees

September 22, 2008 by Elizabeth Thomson
The sensor system produces enough electricity to allow the trees' temperature and humidity sensors to regularly and wirelessly transmit signals. Each signal hops from one sensor to another, until it reaches an existing weather station that beams the data by satellite to a forestry command center. Graphic / Rebecca Macri

(PhysOrg.com) -- MIT researchers and colleagues are working to find out whether energy from trees can power a network of sensors to prevent spreading forest fires. What they learn also could raise the possibility of using trees as silent sentinels along the nation's borders to detect potential threats such as smuggled radioactive materials.

The U.S. Forest Service currently predicts and tracks fires with a variety of tools, including remote automated weather stations. But these stations are expensive and sparsely distributed. Additional sensors could save trees by providing better local climate data to be used in fire prediction models and earlier alerts. However, manually recharging or replacing batteries at often very hard-to-reach locations makes this impractical and costly.

The new sensor system seeks to avoid this problem by tapping into trees as a self-sustaining power supply. Each sensor is equipped with an off-the-shelf battery that can be slowly recharged using electricity generated by the tree. A single tree doesn't generate a lot of power, but over time the “trickle charge” adds up, “just like a dripping faucet can fill a bucket over time,” said Shuguang Zhang, one of the researchers on the project and the associate director of MIT's Center for Biomedical Engineering (CBE).

The system produces enough electricity to allow the temperature and humidity sensors to wirelessly transmit signals four times a day, or immediately if there's a fire. Each signal hops from one sensor to another, until it reaches an existing weather station that beams the data by satellite to a forestry command center in Boise, Idaho.

Scientists have long known that trees can produce extremely small amounts of electricity. But no one knew exactly how the energy was produced or how to take advantage of the power.

In a recent issue of the Public Library of Science ONE, Zhang and MIT colleagues report the answer. “It's really a fairly simple phenomenon: An imbalance in pH between a tree and the soil it grows in,” said Andreas Mershin, a postdoctoral associate at the CBE." The first author of the paper is Christopher J. Love, an MIT senior in chemistry who has been working on the project since his freshman year.

To solve the puzzle of where the voltage comes from, the team had to test a number of theories - many of them exotic. That meant a slew of experiments that showed, among other things, that the electricity was not due to a simple electrochemical redox reaction (the type that powers the 'potato batteries' common in high school science labs, en.wikipedia.org/wiki/Lemon_battery). The team also ruled out the source as due to coupling to underground power lines, radio waves or other electromagnetic interference.

Testing of the wireless sensor network, which is being developed by Voltree Power (voltreepower.com), is slated to begin in the spring on a 10-acre plot of land provided by the Forest Service.

According to Love, who with Mershin has a financial interest in Voltree, the bioenergy harvester battery charger module and sensors are ready. “We expect that we'll need to instrument four trees per acre,” he said, noting that the system is designed for easy installation by unskilled workers.

“Right now we're finalizing exactly how the wireless sensor network will be configured to use the minimum amount of power,” he concluded.

The original experiments were funded by MagCap Engineering, LLC, through MIT's Undergraduate Research Opportunities Program.

Provided by MIT

Explore further: What causes lightning?

Related Stories

What causes lightning?

July 10, 2015

Thunder and lightning. When it comes to the forces of nature, few other things have inspired as much fear, reverence, or fascination – not to mention legends, mythos, and religious representations. As with all things in ...

Cellulose from wood can be printed in 3-D

June 17, 2015

A group of researchers at Chalmers University of Technology have managed to print and dry three-dimensional objects made entirely by cellulose for the first time with the help of a 3D-bioprinter. They also added carbon nanotubes ...

Latest self-driving Google car heading to public streets

May 15, 2015

The latest version of Google's self-driving car—a pod-like two-seater that needs no gas pedal or steering wheel—will make its debut on public roads this summer, a significant step in the technology giant's mission to ...

Galaxy-gazing telescope sensors pass important vision tests

April 28, 2015

When you're building a massive telescope designed to detect subtle shapes in the light emitted by distant galaxies, you'd like to know that the shapes you are seeing are accurate and not the result of defects in your telescope's ...

Video: Solar power from energy-harvesting trees

February 16, 2015

Scientists at VTT have developed a prototype of a tree that harvests solar energy from its surroundings - whether indoors or outdoors - stores it and turns it into electricity to power small devices such as mobile phones, ...

Recommended for you

Cellphones can steal data from 'air-gapped computers'

July 28, 2015

Researchers at the Ben-Gurion University of the Negev (BGU) Cyber Security Research Center have discovered that virtually any cellphone infected with a malicious code can use GSM phone frequencies to steal critical information ...

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

mysticfree
3 / 5 (1) Sep 22, 2008
Thanks for reporting where the electricity doesn't come from. How about explaining where the it comes from? Or is it safe to assume tree gnomes are responsible for this phenomenon...
tree123
not rated yet Sep 22, 2008
This article explains the origin of the base voltage: http://www.ploson....0002963

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.