| | Category | BO | L13 | Power Plant : Trees Generating Electricity |
| | Abstract | Abstract |
| | The purpose of this experiment was to measure the amount of electrical |
| | voltage produced by trees, and determine what factors, if any, altered |
| | their voltage production. The bioelectric properties of trees provide a |
| | natural source of energy (Himes, 2009) and scientists are beginning to |
| | understand the electrochemistry behind it. They have even developed |
| | small circuits to run off the very low voltages produced by trees. What |
| | remains unknown, however, are what variables affect the amount of |
| | voltage a tree produces. |
| | This experiment looked at the factors of tree size, tree species and air |
| | temperature to determine if there was a correlation with tree voltage. The |
| | study was done in the forest at the University of Michigan – Dearborn |
| | Environmental Interpretive Center. Small devices called HOBOs, which |
| | measured air temperature, humidity, light intensity and tree voltage, were |
| | placed on the trees. The HOBOs were connected to aluminum nails placed |
| | in the tree trunks and the ground around the trees. Soil pH was measured |
| | at each tree. The HOBOs took readings every two minutes and were left |
| | in place for one week at a time. Data was collected for four and a half |
| | months, from August through December, 2010. |
| | Results of the comparison of three different tree species showed a |
| | significant difference in voltage production, with the Northern Hackberry |
| | tree producing the most voltage and the Oak tree producing the least. |
| | Different size trees of the same species (Black Walnut) also showed a |
| | significant difference in voltage production, however results were |
| | inconsistent. There was no correlation between tree voltage and air |
| | temperatures. An unusual finding was that tree voltages reversed polarity |
| | in an apparent random manner, in all trees studied. |
| | The conclusion of this experiment was that tree voltage production can |
| | vary significantly between different tree species. The voltage production |
| | may possibly vary between different size trees, however, more research |
| | is necessary. Air temperature changes had no significant effect on tree |
| | voltage. |
| | Bibliography | Ansari, A. Q., & Bowling, D. J. F., (1971). Measurement of the Trans-Root |
| | Electrical Potential of Plants Grown in Soil. New Phytologist, Vol. 71. (111- |
| | 117) |
| | |
| | Bickelhaupt, D., (N/A). Soil pH: What it Means |
| | State University of New York. Retrieved from |
| | http://www.esf.edu/pubprog/brochure/soilph/soilph.htm |
| | |
| | Calnun, C. (2006). Plugged in: Start up hopes to tap electricity from trees. |
| | Mass High Tech: The Journal of New England Technology. |
| | |
| | Evans, E., (2000). Tree Anatomy. |
| | North Caroline State University. Retrieved from |
| | http://www.ces.ncsu.edu/depts/hort/consumer/factsheets/trees- |
| | new/text/tree-anatomy.html |
| | |
| | Hayt, Jr., W. & Kemmerly, J. E., (1978). Engineering Circuit Analysis. |