Batteries R Us. Storage “Problem” Vanishing

June 18, 2020

Recharge News:

A new type of battery is coming onto the market that can store multiple days’ worth of energy, that doesn’t degrade, can’t possibly explode and is up to five times cheaper than lithium-ion, claimed its developer as it prepares to pilot the technology in New York state.

The zinc-air hybrid flow battery developed by Canadian company Zinc8 has the potential to disrupt the entire energy-storage market — making wind and solar farms baseload and even replacing the need for transmission grid upgrades in many places.

“For large-scale energy storage, lithium-ion can’t touch us on cost,” says chief executive Ron MacDonald, a former Canadian member of Parliament who now oversees a company that has received more than $50m of funding.

Zinc-air can beat lithium-ion batteries on price because the latter can generally only hold about four hours’ worth of energy at any one time, so an eight-hour storage system would require two batteries. By contrast, the storage capacity of the Zinc8 system can just be made bigger by increasing the size of the storage tank and the volume of the electrolyte it contains.

The capital cost of an eight-hour Zinc8 storage is about $250/kWh, falling to $100/kWh for a 32-hour system and $60/kWh for 100 hours. By contrast, lithium-ion projects cost about $300/kWh for any duration over eight hours.

“Our market is eight hours [of storage] and above,” MacDonald tells Recharge. “And the reason is that as you increase your storage capacity — the overall cost of the system continues to go down very significantly.”

In terms of levelized cost of storage (LCOS) — ie, the cost of storing each MWh of energy across a project’s lifetime, taking into account all capex and opex — zinc-air blows lithium-ion away for storage capacities higher than eight hours. This is because the LCOS of lithium systems, for long-duration applications that require daily or multi-day full cycling, roughly doubles for every ten hours of storage capacity added, compared to every 70 hours or so for zinc-air.

This means that a 10-hour zinc-air storage system would have an LCOS of about $100/MWh, compared to $125/MWh for lithium-ion. But a 72-hour zinc-air system would have an LCOS of about $180/MWh, compared to more than $600/MWh for lithium.

The cost of the zinc-air battery is expected to fall significantly as manufacturing is stepped up.

Zinc-air has long been touted as a potentially cheap and powerful form of energy storage, but it always seemed to have a fundamental flaw — the formation of a bumpy coating of zinc on the electrode called a dendrite, which caused short circuits and other problems.

Perversely, Zinc8 found success by embracing this flaw and using it to the company’s advantage.

“Most of the zinc-air battery research was focused on an electrolyte that would eliminate or reduce the dendritic formation,” explained chief technology officer Simon Fan. “We took a totally different approach — we like dendrites.”

Fan’s team invented a process — which remains a trade secret — that easily removes the dendrite from the electrode to “give us beautiful dendritic particles that we can transfer to the storage tank”.

In simple terms, the Zinc8 battery uses electricity from the grid to split the chemical zincate (ZnOH4) into zinc, water and oxygen, resulting in charged zinc particles that can store electricity for weeks at a time. When electricity is required, the charged zinc is combined with oxygen from the air (and water), releasing the stored electricity and producing zincate, which is then cycled back to begin the process again.

The battery itself consists of three parts — the “zinc regenerator”, which generates the charged zinc particles; the storage tank, which contains the potassium hydroxide (KOH) electrolyte and holds the charged zinc; and the power stack, a kind of fuel cell that turns the zinc to zincate and delivers its charge back to the grid.

The zinc can be stored for months in the electrolyte — it literally accumulates at the bottom of the storage tank — although it loses about 1% of its stored charge per day. And these particles are then pumped to the power stack when required, via a proprietary pumping mechanism designed and built in-house, where the charge is extracted and delivered to the grid.

The electrolyte — in which the zinc is formed — does not degrade, being identical at the start and finish of each cycle, and there is no net consumption of zinc, oxygen or water. The only parts of the system that degrade are the electrodes and the power stack, which need to be replaced every few years, depending on usage.

The round-trip efficiency of the system — ie, the percentage of inputted energy that is outputted at the end — is about 65%, a far cry from lithium-ion’s 95%, but this is accounted for in the LCOS figures.

Recharge News:

The notion that the variability of wind and solar is problematic is a “myth”, according to one of the world’s most important renewables advocates.

Francesco La Camera, director-general of the International Renewable Energy Agency (Irena), tells Recharge that there will soon be so many methods available to store renewable energy and help balance the grid that intermittency will not be an issue. 

These include “ever more competitive” batteries; build-anywhere long-duration intermittent-energy storage (Baldies) technologies such as liquid-air and hot-rock thermal; district heating and cooling; electric-vehicle charging, green hydrogen, demand response, concentrating solar power with molten-salt storage, smart grids and interconnection. “These technologies will solve [variability]. They are already solving it,” the Italian explained on the sidelines of European Utility Week in Paris.

He pointed to projects such as the Eland Solar & Storage Center near Los Angeles — 400MW of PV paired with 300MW/1,200MWh of batteries — which will supply combined solar and energy storage for $33/MWh from 2023. This is the same price as the average marginal cost of operating existing coal-fired and nuclear power plants, according to recent analysis from investment bank Lazard.

“The fact is that when we are all going in one direction [in the energy transition], it will be easy to find a technological solution — which are mostly already there. If 50 years ago, we were able to go to the Moon, you really think it’s now more difficult to make a grid flexible and stable?”

9 Responses to “Batteries R Us. Storage “Problem” Vanishing”

  1. dumboldguy Says:

    Aside from the last paragraph, which speaks of “easy technological solutions” and then “apples and oranges” going to the moon with fixing the grid, an interesting article. Two questions—-why haven’t we heard much of zinc-ion batteries before? and is there anything near a real world working size model that demonstrates that it actually works?

  2. Sir Charles Says:

    • Brent Jensen-Schmidt Says:

      This is a straight question. How TF is this thing supposed to STORE energy? Anyone?

      After ‘massive’ energy input, get a load of frozen air with every minuscule erg of energy removed and at ambient pressure. What is the point? As I said, this is a straight question.

      • mboli Says:

        You boil the solid or liquid air, and use the expanding gas to run a turbine.

        You can use air or water from the environment to boil the liquid air. Essentially using the liquid air to cool the whole outdoors.

        Or (I just learned) you can use waste heat from some other process, like for example the low grade waste heat from a fossil fuel generator.

        • Brent Jensen-Schmidt Says:

          They are burning gas to provide the heat at the moment. It is a physics question. Still cannot see the energy gain from heating frozen air as against ambient air. Where is the ENERGY gain by cooling the air then heating it again. Using waste heat to produce power is magic in several ways and it bugs me.

      • dumboldguy Says:

        Put this in the same folder you store your Solar Roadway info in It’s almost laughable, except that $$$ and time and energy are being wasted on it.

        By the way, does anyone know how the “raise and lower weights in a mine shaft” to store energy projects are going?

  3. Reblogged this on The Most Revolutionary Act and commented:
    A new type of battery is coming onto the market that can store multiple days’ worth of energy, that doesn’t degrade, can’t possibly explode and is up to five times cheaper than lithium-ion, claimed its developer. The zinc-air hybrid flow battery developed by Canadian company Zinc8 has the potential to disrupt the entire energy-storage market — making wind and solar farms baseload and even replacing the need for transmission grid upgrades in many places.

  4. Brent Jensen-Schmidt Says:

    This is looking real despite the ‘secret process’ which usually signals scam. Do not breakout the champagne yet, the requirement is still to Stop producing GHG. Also the variability of renewable power is not a myth, it is a bluddy big problem. Batteries, even ones with 65% return help a lot, but not with continent wide storage.

  5. Gingerbaker Says:

    We will soon have 100 gigawatt hours of battery storage available just from reserved Cybertrucks, which will supposedly come with car to home/grid tech built in. Imagine if we had 50% BEV share.

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