Sep 10 2009

Tree Power

Posted by: Jonathan Marshall

How's this for the ultimate in renewable green energy: tree power.

A team of University of Washington researchers has tapped the minute electrical currents in trees to power an electronic circuit for what they say is the first time.

Last year, MIT scientists demonstrated the existence of very small voltages between trees and the ground. You can see for yourself a demonstration on YouTube (as well as this cautionary tale).

Using a power booster, the University of Washington team was able to amplify the few hundred millivolts of potential between the ground and bigleaf maples on the university campus to run low-power sensors at 1.1 volts.

In this case, low power really means nanopower: The circuits consumed only 10 billionths of a watt.

"It's not exactly established where these voltages come from," said co-author Babak Parviz, an associate professor of electrical engineering at the university. "But there seems to be some signaling in trees, similar to what happens in the human body but with slower speed."

"As new generations of technology come online," he added, "I think it's warranted to look back at what's doable or what's not doable in terms of a power source."

Hmmm . . . Maybe if PG&E customers keep saving forests through their contributions to the ClimateSmart(tm) program, we can wire all those trees with electrodes and hook them up to our grid. Should be enough for a few fluorescent bulbs at least. Who could object to such green power?

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