Can Zinc batteries save us?

Preface: The New York Times had two articles about zinc air batteries in September 2018.  Right now, finite natural gas is the dominant way of balancing unreliable, outright missing, or intermittent power from wind and solar.  So other energy storage solutions simply have to be invented to replace natural gas, and zinc air is one way to do this.  Zinc air batteries are only proposed for energy storage, not electric vehicles.

Penn (2018) states that there are only 25 years of zinc reserves left.  As if that weren’t alarming and astounding enough, the article goes on to say that lithium reserves are even smaller – just 5% of zinc reserves.

Yet I suspect the average reader will come away from reading this article with optimism that progress is being made and not have alarm bells triggered by the 25 years of reserves.

The articles neglect to say that there are other problems with zinc batteries.

As you can see, compared to natural gas, the energy storage of batteries per unit weight pales in comparison.

Specific energy is the amount of stored energy per mass unit (i.e. kilogram or liter). Source: Kurt Zenze House. 2009. The limits of energy storage technology.

It also takes far more energy to create batteries to store energy for a much shorter time of operation before the battery needs to be replaced. If you look at the energy stored over the lifetime of a storage device, compared to the energy used to build it, compressed air energy storage and pumped hydro storage ate orders of magnitude cheaper and more effective than batteries, with zinc-bromide near the bottom:

This graph shows the ratio of electrical energy stored over the lifetime of a technology to the energy needed to build it. Stored energy over the lifetime depends significantly on the cycling life, the efficiency, and the depth of discharge. Source: Charles J. Barnhart (2013) On the importance of reducing the energetic and material demands of electrical energy storage.

The deployment challenges of zinc-air batteries also include poor reversibility and resultant cycling problems due to metal plating, as well as evaporation of the aqueous electrolyte when used in an open system (Parfomak 2012).

Alice Friedemann  author of “When Trucks Stop Running: Energy and the Future of Transportation”, 2015, Springer and “Crunch! Whole Grain Artisan Chips and Crackers”. Podcasts: Derrick Jensen, Practical Prepping, KunstlerCast 253, KunstlerCast278, Peak Prosperity , XX2 report ]


Zinc air batteries have been lauded for their potential cheap energy storage, much lower than lithium-ion, though experts cautioned that the actual cost varied a great deal depending on the application, making it hard to compare with lithium batteries.

Zinc is also much less toxic than lithium, or a fire hazard like lithium.  Though it’s not completely safe — the ore is zinc sulfide and produced along with lead, cadmium, and nickel which can cause harm from sulfur dioxide and cadmium-vapors.

More importantly, Dr. Narayan, professor of chemistry at the University of Southern California, said reserves of lithium, a primary element in lithium-ion batteries, were only 5% of the reserves of zinc.  But, he noted “At the present rate of production of zinc, zinc reserves will last about 25 years. So it is not clear from the reserves available if we will have enough zinc to support the enormous need that will result from the demand for grid-scale batteries.” (Penn 2018).

Mr. Cooper, senior research fellow for economic analysis at the Institute for Energy and the Environment at the Vermont Law School pointed out that fracked gas has taken attention away from the need for alternative ways to store energy, since natural gas is the main way the intermittency, unreliability, and complete lack of wind and solar are coped with now.  Cooper noted that capitalism doesn’t deal with problems where there isn’t scarcity, so money isn’t flowing into battery energy storage research and development (Penn 2018b).

Parfomak, P. W. 2012. Energy Storage for Power Grids and Electric Transportation: A Technology Assessment. Congressional Research Service.

Penn, I. 2018. How zinc batteries could change energy storage. New York Times.

Penn, I. 2018b. Cheaper battery is unveiled as a step to a carbon-free grid. New York Times.

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One Response to Can Zinc batteries save us?

  1. NJF says:

    I also heard aluminum-air batteries were a thing? Much more aluminum than zinc but likely similar pitfalls.

    Aluminum and zinc batteries that have oxygen as the oxidant are held in high regard because the idea is that it cuts the weight down but if that were the case why doesn’t everyone invest in the tech and use it? Then you start looking more into it and then the mask starts slipping and the fatal flaws become obvious.