What are soil batteries?
Soil batteries are water-activated batteries that produce an electrical current using electrochemical reactions in the soil. They are made from four components: copper cathodes, zinc anodes, copper wires, and wet soil. An earth battery can produce enough energy to power lamps and radios in off-grid locations.
How do soil batteries work?
Like all batteries, they rely on the exchange of electrons from zinc and copper electrodes to produce an electrical current. The electrodes are immersed in an ion-rich electrolyte solution where electrons from zinc transfer to copper, generating the electrical charge we use to power our electrical devices.
However, unlike other batteries, earth batteries use wet soil or bacteria-rich compost as the electrolyte solution instead of acids. Organic matter releases electrons as it decomposes, which can be captured by the electrodes. Electrons are also discharged when bacteria eat organic matter like they do in compost piles.
How are they made?
Earth batteries can be made by anyone. The biggest considerations you would need to make before building an earth battery are the amount of energy you want from it and the amount of soil you can access. The more energy you want to produce, the more soil with bacteria you will need. There are numerous guides online that you can easily follow and use to construct your own soil battery, such as https://saturday-club.org/online/energy-under-our-feet/.
How sustainable are soil batteries?
Just about anything that transforms chemical energy into electrical energy is a battery. Here, chemical energy is created by converting electrical energy. Plants are the capacitor while the soil is a battery. We benefit from specific organic substances that are naturally transported by water, as well as the ability to obtain energy from soil terrains and other sources. Unlike other batteries that are only adapted for wastewater treatment and not built to withstand harsh environments, these biological batteries can adapt to the environment.
In terms of sustainability, using soil batteries as a battery to store energy, as opposed to expensive and toxic metal batteries, are much more advantageous for present and future uses. To maintain the ecosystem without harming it, we can use this soil battery, a biological battery capable of producing electricity by feeding on natural soil and using plants.
The Future of Energy
Our issues with energy storage don't only have to be solved by soil batteries. In actuality, hydro projects are the most popular type of energy storage in the world. Controlling the amount of water in an upper and lower pool is how pumped storage hydropower plants operate. The "water battery" at the top is released when electricity is required, rotating a turbine that produces hydroelectric power.
Another, more recent innovation is sand batteries. To produce and store heat, they utilize grains. In Finland, one is already operational and has the capacity to supply the district heating network for many months. Not only have solar, wind, and hydropower experienced astounding advancements, but the cost of producing clean energy has also fallen dramatically. It is now much less expensive than fossil fuels.
Renewable energy sources surely have the potential to meet all of our electricity needs and strive towards a green revolution with further development, including solar and wind generation and possibly some other sources like geothermal and tidal power.
Limb L. How batteries will supercharge the renewable revolution [Internet]. euronews. 2022 [cited 2022Nov17]. Available from: https://www.euronews.com/green/2022/07/21/the-race-for-renewable-batteries-whats-the-future-of-solar-and-wind-storage
Limb L. Underground 'bugs' could be the future of Solar Energy Storage [Internet]. euronews. 2022 [cited 2022Nov17]. Available from: https://www.euronews.com/green/2022/09/30/soil-batteries-solar-power-could-one-day-be-stored-in-the-ground-beneath-our-feet
McDonough W. Can soil replace oil as a source of energy? [excerpt] [Internet]. Scientific American. Scientific American; 2013 [cited 2022Nov17]. Available from: https://www.scientificamerican.com/article/soil-to-replace-oil-for-energy-upcycle-excerpt/
Staff MC. What is an earth battery, and how does it work?: Aspiration [Internet]. Make Change - Where Money and Mission Meet. 2022 [cited 2022Nov19]. Available from: https://makechange.aspiration.com/earth-battery/
Edwards CR. Earth Battery Build [Internet]. National Saturday Club. 2020 [cited 2022Nov19]. Available from: https://saturday-club.org/online/energy-under-our-feet/