A portion of this video is brought to you
by Surfshark. When it comes to grid-scale energy storage,
redox flow batteries (RFB) are one of the big competitors for lithium-ion batteries. In preliminary tests, RFBs can be manufactured
with longer lasting lives, be made more scalable, and are easier to recycle than other battery
technologies. Yet, after investing millions of US tax dollars
into a cutting edge RFB formula, the American government basically gave it away to China,
who is currently the lead producer of RFB. So, how did this invention flow out of the
US? And why should we even care about redox flow
batteries? Let’s face it. Installing tons of solar panels and wind turbines
is not going to be enough to decarbonise our energy system. We desperately need cost-effective batteries
to store spare renewables and reuse them when we need them most. According to the US Department of Energy (DOE)’s
National Renewable Energy Laboratory (NREL), the American energy storage capacity should
experience an over fivefold increase by 2050 to meet the country's zero-carbon electricity
demand. Funny enough, the very same department gave
away a promising storage technology to China a few years back. Before trying to make sense out of this crazy
story, let’s understand what RFBs are all about. The key components of this system aretwo electrolytes,
which are liquid solutions containing active elements in a different oxidation state. Unlike lithium-ion batteries, where a single
electrolyte floats inside the cell, in a flow battery two solutions storing the chemical
energy sit inside external tanks. During the battery operation, these electrolytes
flow from the tanks towards a central chamber. In its simplest design, this chamber, a.k.a. stack, features two half-cells separated by
an ion-selective membrane. So, what about the “redox” bit? This term refers to the red-uction and ox-idation
reactions the chemicals dissolved in the solutions are subjected to. To be more specific, upon discharging, the
ions in one of the tank-cell pairs, called anolyte, increase their oxidation state. In other words, they lose electrons. Traveling through an external circuit, these
electrons by-pass the membrane and reach the other side, i.e., the catholyte. Here, ions take up the electrons and reduce
their oxidation state. To recharge the battery, you just connect
it to the grid and use the incoming electrons flow to reverse the redox process. Depending on the active elements in the electrolyte,
there are various types of RFB. However, the all-vanadium configuration is
currently the most widely commercialized. So, why vanadium? Not because it’s the most beautiful element
in the world. Rather, this metal can have multiple oxidation
states, which comes in handy when you rely on the redox mechanism. By harnessing vanadium’s chemical versatility,
you don’t need to introduce any other element into the electrolytes except sulfur. Basically, you use a mild sulfuric acid solution
to dissolve vanadium sulfates. After doing that, you’re left with two vanadium
redox couples, namely V2+/V3+ in the anolyte and V4+/V5+ in the catholyte. This removes the cross-contamination risk
implied by other designs. Which is why vanadium RFB can last up to 4x
more than any other comparable device. Lithium-ion batteries are great for short-term
applications but RFB are more apt for long-duration storage. RFB’s supply chain is also greener as their
components are more recyclable, which reduces the amount of waste ending up in landfills. It’s for this reason many believe they’ll
play a key role in the future of energy storage. Yet, this technology is nothing new. NASA began developing them during the energy
crisis in the 70s. After three decades of lackluster results,
2006 was a breakthrough year. As several patents expired, it opened up private
companies to get their creative electrolytes flowing. Also, in that same year, US researchers started
working on an improved recipe for an RFB. After 6 years of efforts funded by over 15
million American taxpayer dollars, scientists came up with a vanadium-based electrolyte
formulation twice as powerful as similar mixtures. On top of that, their battery could perform
well for up to 30 years without showing any sign of degradation. So, what was their trick? They simply swapped the conventional sulfuric
acid solution with a blend of hydrochloric and sulfuric acid. When using this modified mixture, they increased
the solubility of vanadium, which boosted the electrolyte energy density. The benefits didn’t stop there though. The acidic mix could work on a wider range
of temperatures compared to the pure sulfuric acid solution, which reduces heating and cooling
costs. Supercharged by those electrifying findings,
in 2012 the research group leader, Gary Yang, applied to the DOE for a license to commercialize
the batteries outside of the lab. Once he signed the agreement, he launched
the startup UniEnergy Technologies. However, because of the long time needed for
his battery to generate returns, Yang claimed he struggled to persuade US investors to sponsor
his creation. Using that as an excuse, he turned to the
Chinese company Dalian Rongke Power Co. Ltd, and in 2017 granted them an official sub-licence
to manufacture some of the batteries in China. And this is where things went wrong. But before I get into that, I’d like to
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supporting the channel. Now back to where things went wrong with this
new battery chemistry. Although the license entailed making most
of the batteries in the US, battery production gradually switched from America to China. According to people I spoke to that worked
at UniEnergy at the time, the key components of the battery were never built in the US
at all, but instead built in China and shipped to the US for assembly and testing. To make matters worse, UniEnergy continued
its shifting of this US funded tech to outside the US by transferring its license to the
European company, Vandals Power in 2021. According to Yang, the underlying issue is
that, unlike China, the US doesn’t have the supply chain to meet production demand. Yet, this infrastructural gap wasn’t created
overnight. Over the last 10 years, China issued a series
of national policies that flowed a lot of cash out of the government coffers to scale
up vanadium RFB. So it shouldn’t be a surprise that after
6 years of development and a 300 million dollars of investment, last May a 100MW/400MWh demonstration
facility was connected to the Dalian grid. And guess who made that battery? Yep, Dalian Rongke Power Co. Ltd. While this facility is already the world’s
largest RFB, the final installation will create twice as much power. I couldn’t find confirmation that this facility
is using the mixed electrolyte, but I did hear from sources that Dalian is currently
manufacturing the new electrolyte in large quantities. But the craziness of this story doesn’t
stop there. Remember how the license was transferred to
Vanadis Power? Well, as mentioned on their website[^18],
the company is contributing to the Dalian Rongke Power China-based project. Nonetheless, EU regulations will force Vanadis
to set up a factory in Europe. You would think that the US government should
be as reluctant as Europe when it comes to moving a US-funded invention overseas, right? Nevertheless, UniEnergy Technologies magically
got away with that twice. I can hear you already. How on earth did that happen? As revealed by an NPR investigation, the DOE
failed to enforce its own licensing rules. When interviewing DOE officials, the Government
Accountability Office found they were struggling to track their licenses because of a limited
budget and inadequate IT systems. What’s even more absurd is that a Washington-based
company, like Forever Energy, has been trying to get a license for this technology for over
a year. Apparently, the DOE has now revoked the Dalian
Rongke Power Co. Ltd license. Although it’s too late to stop Chinese battery
expansion, perhaps the US government is still in time to prevent Forever Energy from changing
its name to Forever Waiting. Awkwardly, the US funded the project with
tax dollars, then sent it to China, and now a domestic manufacturer is blocked from making
them. I actually had a chance to speak to Forever
Energy about this whole debacle, as well as about the technology they’re trying to bring
to market. They have a modular battery design that takes
advantage of the mixed electrolytes' increased energy density. Single acid RFBs are usually pretty large
and relegated to grid scale application, but Forever Energy has a working design that’s
roughly the size of a refrigerator and can store up to 40 kWh of energy. The best part is that it should be cost competitive
with similar sized lithium ion battery systems, but last 30-40 years. It’s a solution meant to take on the residential
energy storage market. If they can secure the license, they’re
definitely a company to keep your eye on. There are some alternatives to UniEnergy’s
electrolyte recipe. For instance, US Vanadium claims to make the
most pure electrolyte in the world. As heralded by the company, their formulation’s
ultra-high purity increases the efficiency of vanadium RFB. Having bought 580,000 liters of it, the energy
storage provider CellCube seems to back their battery elixir. Galvanized by this deal, last September US
Vanadium invested $2.1 million to expand their Arkansas-based electrolyte production. CellCube will use US Vanadium’s solution
to fuel an 8MWh system in Illinois. This system will support a microgrid system
and integrate with rooftop solar panels and a flywheel. While this is a much lower-scale application
compared to the one developed by Rongke Power, it relies on a 100% US supply chain. But there are some bigger projects underway
as well. The California non-profit energy supplier
Central Coast Community Energy (CCCE) is planning to have up and running vanadium RFB installations
for a total capacity of 226MWh by 2026. Being able to back up the grid for up to 8
hours, these storage systems will be crucial to mitigate the effect of climate-induced
blackouts that will occur in the state over the next few years. Whether being produced in the US, China or
elsewhere, RFB could help us make the most out of our renewables capabilities by providing
viable energy storage during times of overgeneration. Having said that, while vanadium is relatively
abundant, its conversion into vanadium pentoxide, the typical raw material for RFB, is highly
localized. With Chinese and Russian mills accounting
for 75% of global production, you can probably see why diversifying its value chain is fundamental
to catalyze the mass adoption of vanadium RFB. However, on that note, there are many ways
to acquire vanadium, including from fly ash. The company US Vandium in Hot Springs, Arkansas
produces high quality vanadium using that method. The recent passage of the Inflation Reduction
Act here in the US is also going to have a major impact on scaling up more local production. But how do RFB compare against the status
quo lithium-ion batteries? First of all, unlike typical lithium-containing
electrolyte, vanadium-based solutions are not flammable. This means you won’t have any risk of thermal
runaway in case of faults or mishandling. Besides a greater flammability safety, RFB
are also better for the environment. A recent life cycle assessment compared the
eco-impacts of vanadium RFB and lithium-ion batteries. Even when using 100% virgin vanadium, RFB
were found to be greener than lithium-ion storage devices in terms of land acidification,
particulate matter (PM) release and human toxicity. What’s more is that replacing 50% of the
feedstock with recycled vanadium would further reduce its global warming contribution. And that’s feasible in the real world. Remember US Vanadium? Last year the company recovered 97% of their
spent electrolyte in a demonstration project. However, on the lithium ion battery side,
there are many startups that have been improving lithium recovery and their costs. Another key advantage for RFB is a more flexible
design than self-contained systems such as lithium-ion batteries. When it comes to RFB, energy and power output
are decoupled, or independent if you like. Increasing the storage capacity would be just
down to expanding external tanks holding the electrolyte. No need to add more cells to the stack … or
add to the stack itself. For long-duration applications, when you need
to deliver many kWh, switching to RFB will save power waste and costs, which can dispatch
electricity for 12 hours or more. In theory, they could go even higher, but
in practice you need to factor in costs. Same applies to lithium-ion batteries, whose
most economical storage duration is capped at around 6-8 hours. In addition, thanks to its lower degradation,
RFB have a lifespan of up to 30 years (in some cases it may be longer). In comparison, typical lithium-ion devices
can last for about 10 years or so (depending on use). Once again, other designs such as lithium
titanate-based cells could run for much longer but they’re not as financially viable. On the other hand, RFB’s round trip efficiency
(RTE) is around 85% if you’re lucky, while lithium-ion sits around 95%. One practical safety issue is the long-term
storage of acidic solutions. While RFB’s are less flammable, their use
of hydrochloric acid and sulfuric acid means these corrosive and toxic chemicals must be
stored onsite, perhaps outside your home. Not just a little bit, either, but many liters
of it, depending on your power needs. When this system is damaged or eventually
corrodes, the leak could be hazardous. With proper engineering and maintenance, that
shouldn’t be a major concern, but it’s still important to keep in mind. So, what about costs? A recent simulation compared the economics
of lithium-ion and vanadium RFB batteries when integrated with a 636 kW PV facility
in southern California. Researchers found that the system can achieve
a levelized cost of electricity (LCOE) below $0.22/kWh using either of the storage technologies. Interestingly, they also mentioned that vanadium
RFB would make more sense in hotter climates, where lithium-ion devices age faster. When it comes to levelized cost of storage
(LCOS), duration is a key factor. Specifically, at discharging times lower than
4 hours, lithium-ion batteries work out cheaper. Conversely, for longer durations vanadium
RFB become more cost-effective. On the other hand, when considering transmission
systems as use case, RFB are more expensive than lithium-ion, pumped hydro and compressed
air storage technologies. Just to give you some perspective, the vanadium-based
system is the lowest-cost option among RFB, with an LCOS as low as $314/MWh. In contrast, relying on compressed air would
let you store energy for only $116/MWh. With more investments in efficiency improvements,
in 2030 RFB will be one of the most competitive storage solutions for discharge times above
4 hours and requiring more than 300 cycles per year. For instance, a 1% RTE efficiency increase
would make RFB displace lithium-ion for high frequency applications. Clearly, giving away our electrolyte recipe
to China was a terrible mistake and we will continue pay for it. And an American company who is actively trying
to bring this technology to market is still struggling to get the license to do so. But there’s still time for redemption. We already have the expertise, so catching
up is just down to building out a solid supply chain. Being more sustainable, scalable and durable
than lithium-ion devices, the US should bet on this technology without losing its returns
this time. If this long-term energy storage tech pans
out, we’ll keep our grid flowing when climate-driven disruptions hit. So are you still undecided? Do you think the US can catch up and that
flow batteries can make a difference? Jump into the comments and let me know and
be sure to check out my follow up podcast Still TBD where we’ll be discussing some
of your feedback. If you liked this video, be sure to check
out one of these videos over here. And thanks to all of my patrons for your continued
support, and a big welcome to new Producers AG Ballew and Crispvash. And thanks to all of you for watching. I’ll see you in the next one.
