Earth Battery

 
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The Earth Battery is capable of tapping omnipresent global electric currents. It gives us the opportunity to connect with the long past and future of these forces and places us in relationship with geologic and celestial time. Viewing the Earth as a battery allows us to consider how we may recharge or drain the resources we find on our planet. It is an invitation to connect to the ground and observe how the most mundane patch of Earth can be valued. An Earth Battery works two ways. First, It is a voltaic battery cell where two dissimilar metals, think zinc and copper, exchange electrons through a spontaneous redox reaction using soil as an electrolyte. The flow of electrons from the zinc to the copper creates a direct current. While localized conditions affect the level of current, any soil will generate a current between the electrodes of the Earth Battery. When the zinc anode and copper cathode are sufficiently separated, the battery can tap telluric currents, the magnetic currents that run through the Earth. Tapping telluric currents is the second way that an Earth Battery can generate voltage. In this project, I designed three iterations of the Earth Battery that tap telluric currents, give evidence of and connection to the omnipresent forces running through the Earth and send a slow and silent message to the future.  

Context and Research

Alessandro Volta first discovered the potential difference between dissimilar metals in 1799 with the Voltaic Pile. His early battery created sandwiches of zinc, electrolyte soaked boards and copper that produced a consistent spark. The larger the stack of metal and electrolyte, the larger the spark. Volta created his battery to disprove Luigi Galvani’s theory that animals generate electricity. Galvani was using dissimilar metals to create twitching in dismembered frog legs and theorized that the source of the current was in the animal, not the metals. The Voltaic Pile removed the frog from the equation and still generated a spark proving that the different metals’ reaction with the electrolyte generated the current, not the frogs. This is the origin of electrochemistry. Copper and Zinc electrodes are used because they have a high potential electron difference. In the redox reaction, the zinc happily gives up two electrons, becoming positively charged Zn+2(aq), and the copper receives these electrons becoming Cu(s). The Earth Battery is a voltaic cell based on the same electrochemical reaction that Volta discovered.

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In 1841, Alexander Bain, who invented the first electric clock, developed one of the earliest examples of an Earth Battery. Bain planted two electrodes about one meter apart to drive a prime mover, a device that converts electrochemical energy into mechanical energy. Daniel Drawbaugh, who claimed to have invented the telephone but lost the patent to the Bell Telephone Company, holds an 1879 patent for using an Earth Battery to run an electric clock. I was inspired by this patent because it connected the Earth, and its time scale, to humans and our time scale. George Dieckmann received an 1885 patent that showed how cells of Earth Batteries could be linked together to increase voltage. In Dieckmann’s patent, the copper cathode of one cell is planted in close proximity to the zinc anode of the next cell, creating an underground flow of electrons between battery cells that increases the net voltage of the system.

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Telluric currents are electromagnetic waves that move through the upper mantle of the Earth’s surface and are what gives the planet its magnetic poles. The currents are caused by a range of factors but the most notable are the rotation of the Earth, solar winds and magma flow with in the Earth’s core. They are affected by both celestial and internal forces. The strongest currents move from the equator towards the magnetic north and south poles. Telluric currents give us a way to measure the conductance of the planet. In industry, the magnetic difference between two points can be used for geothermal exploration, finding mineral deposits and oil prospecting. Alternatively, they can be a means of poetic connection to the planet. The forces that create these currents connect the most inherent features of our solar system into an observable and useable flow of electrons.

Earth Battery V1

For me, the connection between utility, the Earth and electricity became a great metaphor through which to reframe the human-Earth relationship. My first iteration of an Earth Battery was a proof of concept. I based my design on Dieckmann’s chaining patent by creating a bracketing system that held copper and zinc electrodes in parallel so that they could be connected in sequence. The bracket is made of redwood so that the metal electrodes only react with each other chemically. I took the battery to Golden Gate park to test both the design and the overall notion of the Earth Battery. The test was successful in that I was able to draw a current from my simple apparatus and, because it had recently rained, installation was easy. However, I became concerned that the design of the bracket would not withstand planting into harder ground and I was disappointed in the DIY nature of the device. While it was successful in drawing a current, this first device was temporary, nearly invisible and opportunistically constructed based on what I could gather and fabricate. This first iteration lacked the gravity and durability to effectively engage with Earth’s omnipresent forces.

Earth Battery V2

To move beyond what I could personally make and to engage more directly with the tools of design, I decided to create the rest of my proposals digitally. The irony of proposing a new relationship to the Earth digitally is not lost on me. However, CAD allows for a level of detail and iteration that is unachievable in any other way. Further, digital tools create space for imagination beyond the restrictions of the physical world. I was able to both increase the specificity of the objects I proposed and expand the scale of the proposal itself.  

The second iteration of the Earth Battery was temporal like the first, aimed at observing the presence of the Earth’s currents on a human time scale. The anode and cathode are held in separate hardwood brackets that tie to a vertical member so that transmission of the current happens eight feet in the air. This increases both the physical presence of the battery and makes it so that humans and other land animals can pass under the transmission line without disturbing it or being disturbed. The units can be chained together by planting an anode close to a cathode but they are not physically tied together. The vertical member is softwood with copper inlay on its edges. I chose materials that could be biologically composted or recycled by humans on a short time scale. Like the first proposal, this iteration of the Earth Battery can be constructed quickly on site but it has a more lasting potential because of the scaled up electrodes and addition of the vertical member.

Earth Battery V:3

The third proposal extends the time scale of the Earth Battery and incorporates evidence of the current in to its design. This proposal moves from quickly compostable materials, like wood, to materials that are digested by the Earth on a long time scale. This iteration proposes separate anode and cathode units, like the second proposal, but rather than having a wooden bracket, I’ve designed a basin made of Granite with Porphyry Copper Deposits surrounding the anode and cathode respectively. The basin collects rainwater and erodes over time and is designed to provide evidence of the Earth’s current. As the basin erodes the copper ore dissolves into the rainwater and combined with the earth’s current, begins to collect on the cathode, this is reduction. The zinc anode experiences oxidation and visibly diminishes as the solid zinc loses electrons and becomes part of the liquid in the basin. This process of oxidation and reduction is the spontaneous redox reaction that is happening within the battery but is contained in the basin, above ground, so that the current becomes observable.

The time scale of the battery and its evidence is intentionally long and subtle. It is a way to convert the very long history and future of the omnipresent Earth currents to a human scale. We can observe the pace of the Earth in the basin both as it erodes and as it highlights the spontaneous redox reaction. By placing the anode and cathode along the magnetic meridian and far apart (65.617 ft) the battery should tap telluric currents. The overarching gesture of this project is to use the intrinsic and omnipresent currents flowing through the Earth to induce an electrochemical reaction that places people in a relationship with the natural world while encouraging us to be more comfortable with long term thinking.