You know that tingling sensation when you touch certain trees? Now scientists are figuring out how to tap into that organic electricity to power your devices

A fascinating scientific study has explored the possibility of harvesting electricity from an unusual renewable source - trees. Researchers found that a small voltage exists naturally between a living tree and the surrounding soil, arising from interactions between the tree's sap flow, cell physiology, and the environment.¹ While the voltage measured so far is minuscule - around 0.1-0.8 volts - the tantalizing concept of "tapping into tree power" has taken root.

Scientists estimate there are over 3 trillion trees on earth.² Could global forests provide a free and renewable energy source for powering small electrical devices? Let's crunch the numbers on tree power potential.

The study tested five metal electrodes inserted into a poplar tree and the ground. The best electrode generated around 0.85 volts - enough to lightly power an LED light.³ To extrapolate globally, assuming an average voltage of 0.5 volts per tree, Earth's 3 trillion trees could theoretically produce 1.5 trillion volts of electricity. However, the average power generated per tree has been measured at a paltry 0.00002 watts.⁴ So hypothetically, 3 trillion trees could generate 60 billion watts or 60 gigawatts - a modest amount compared to global energy consumption of over 157,500 terawatts.⁵

Of course, actually harvesting tiny amounts of electricity from billions of trees is highly impractical. Yet as electrode technology improves, tree power may one day play a role for low-energy applications like remote forest sensors, ranger equipment or camping gear. The organic, self-sustaining nature of the energy source remains appealing. We may yet see tree-chargers for cell phones or tree-powered watches for eco-conscious consumers.

So don't unplug your laptop to tap into a tree just yet. But in the future, listening to music powered by those woodsy volts might just be how the world turns over a new green leaf.  

References

1. Za,Wang, Li et al. "Effects of Electrode..." PLOS ONE, 2015.

2. Crowther et al. "Mapping tree density ..." Nature, 2015.

3. Za et al, 2015.  

4. Love, Zhang and Mershin. "Source of sustained voltage..." PLOS ONE, 2008.

5. Hay. "World Primary Energy Consumption", 2017.