Trees: better than photovoltaic panels!
About ten years ago, researchers managed to produce electricity by placing copper strips on lemon slices. Today, it would be possible to extract electrical energy from trees in situ, just by implanting electrodes.
In the United States, a team of researchers from a private company, MagCap in Massachusetts, a component manufacturer, worked on a process that could directly harness the plant's electrical energy.
To convince themselves of the existence of such a source of energy, they offer a simple experience, achievable at home: Take an aluminum nail and push it 3 cm into a tree trunk. Then take a copper metal stake and push it about 20 cm into the ground. Connect both ends to a conventional voltmeter and you will find that a voltage of 0,8 to 1,2 volt testifies to the electrical energy involved.
But, if we want to exploit this energy, that is to say if we replace the voltmeter for example by a light emitting diode of the same voltage, then it does not produce light. The problem is that plant electrical energy is unstable and not exploitable as it is, according to Gordon W. Wadle, an engineer at Thomson, who developed the process in collaboration with MagCap Engineering. You have to be able to store it and then restore it.
The circuit composed in particular of capacitors connected in series and in parallel is capable of accumulating electricity in nickel-cadmium batteries, which are capable of supplying electroluminescent diodes up to 2,1 volts. The researchers have already made some interesting remarks, notably that the electric energy produced by trees is more important in winter than in summer.
At this point, many questions remain about the potential of such a technique. How much electricity can a tree produce? Isn't the assembly polluting by transfer of the metals from the electrodes in the tree or the earth? Many see in the patent filed by MagCap, a bright future, with applications such as the supply of electroluminescent panels or even the supply of public lighting or security lights and why not in this Christmas period the fir trees feeding their own garlands ...