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| Fig. 1: California wind farms. (Source: Wikimedia Commons) |
The environmental arena has for long been full of chatter surrounding the rapid innovations in both alternative energy sources and their new storage methods. As concern for climate change looms, major companies, private and public, have scoured the globe in search of the markets next energy cash crop. Many have succeeded in uncovering new sources of possible energy, yet few have lived up to the expectations required in order to deliver a viable, scalable, and sustainable source and method. One of the largest obstacles facing todays energy innovations is the problem of storage. If new energy sources are few and far between, feasible storage methods might as well be the holy grail. At the frontier of renewable energies, states such as California are more than familiar with this issue and are currently forced to pay other states to take surplus power produced from their solar and wind farms (see Fig. 1). [1] Today, the most common and inexpensive form of storage is the lithium-ion battery, able to both store and recharge energy; recently infamous for its application in Elon Musks Teslas. To provide perspective on the batterys demand, global production of lithium is predicted to surpass 700,000 metric tons by the year 2025, rechargeable batteries accounting for 70% of it. [2] This will only increase if we continue on our recent trend. Batteries, however, are not the only form of energy being storage being pursued; other technologies include compressed air in caves, the long-used pump hydroelectric plant storage, and there are even efforts to manipulating the Hoover Dam into a battery itself. [1] Despite all of this uncertainty, there is hope in the future ... and it may lie in NantEnergys new zinc battery.
The next pioneer in sustainable energy storage, introduced by NantEnergy, capitalizes on the innovative solution using zinc and air. Considering that such a battery would be the first to become commercially available since Thomas Edison was initially stumped by the use of Zinc 100 years ago, NantEnergy's announcement at this years Paris summit has been met with a flurry of excitement. [3]
A zinc battery cell, works similar to that of conventional batteries in that it generates electrical power from chemical reactions. However, instead of including all of their necessary ingredients inside the actual cell of the battery, they rely on oxygen from the outside air to contact an exposed cathode in order to introduce their main reactant. Through this process, by converting zinc oxide into zinc and oxygen, the battery is able to charge - and do so at a much faster rate than lithium ion batteries. In the discharge process, the system produces energy by oxidizing the zinc with air. [1] There a few benefits to this method. First, utilizing a reactant from outside the physical battery, the manufacturers are able to save on space which can ultimately bring down the price and reduce its overall size. Second, unlike its lithium-ion counterpart, zinc and air batteries are neither highly reactive, nor dangerously flammable. Both of these factors make them far more likely to be commercially accepted. In addition, the units briefcase-like design, composed of a circuit board, zinc oxide, and entirely plastic components and casing, eliminates any further possibility of hazard. The primary challenges from here on out will be to make such batteries reliable for continuous use while continuing to reduce the current price of $100 per kilowatt-hour.
As Nant Energy continues to enhance their new storage solution, they must constantly innovate in order to overcome the obstacles facing zinc as a viable product. One such remaining hurdle is the possibility of demand outweighing the world's supply for zinc. Currently, NantEnergy gets its zinc from Indonesia, a supposed plethora, but the US accounts for just 5% of the worlds zinc reserves which some claim are only one-twentieth the size of lithium-ion reserves. According to Dr. Sri R. Narayan, professor of chemistry at the University of Southern California, At the present rate of production of zinc, zinc reserves will last about 25 years. [3] NantEnergy suggests that rather than delivering a product for residential customers in need of a vehicle charge, their immediate focus will be on delivering the new zinc battery for microgrids. Needless to say, a plentiful, safe, and more affordable alternative would be worth a lot; NantEnergy believes the market to eventually be worth $50 billion. [1]
© Charlie Beall. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] I. Penn, "Cheaper Battery Is Unveiled as a Step to a Carbon-Free Grid," New York Times, 26 Sep 18.
[2] S. Patterson, "Lithium Boom Raises Question: What Is Its Price?," Wall Street Journal, 27 Nov 18.
[3] I. Penn, "How Zinc Batteries Could Change Energy Storage," New York Times, 26 Sep 18.
