Are Flow Batteries The Answer to Long-term, Seasonal Energy Storage?

Summary

This episode of the Fully Charged Show delves into the potential of flow batteries, particularly the zinc-bromine variety developed by Redflow, as a solution for long-term and seasonal energy storage. The show takes us to Redflow's R&D facility in Brisbane, shedding light on how these batteries operate, their scalability, and their advantages over traditional lithium-ion batteries. The discussion highlights the batteries' ability to go into hibernation mode for months, operate efficiently at a wide temperature range, and their environmental benefits of using non-toxic and readily available materials like zinc and bromine. While flow batteries are promising, they come with certain operational challenges which are being addressed through innovative design improvements and manufacturing scalability.

Highlights

• Redflow's zinc-bromine flow batteries can hibernate for long-term energy storage. ⏳
• The battery design allows for modular and scalable solutions, suitable for different storage requirements. 🏗️
• They use zinc and bromine, which are abundant and environmentally friendly materials. 🌍
• Innovative designs help these batteries operate in extreme temperatures with simple solutions like heater pads. 🌡️
• Automation in manufacturing is set to increase production efficiency and meet growing demand. ⚙️

Key Takeaways

• Flow batteries can store energy for long durations, even bridging seasonal gaps, thanks to their ability to hibernate. 💤
• Redflow's zinc-bromine batteries are modular and scalable, making them suitable for various storage needs. 🔋
• These batteries are less harmful environmentally and use abundant materials like zinc and bromine. 🌿
• Operational challenges like temperature effects are manageable with design tweaks such as heater pads for colder climates. ❄️
• Flow batteries are being optimized for automated manufacturing to meet high demand efficiently. 🏭

Overview

Ever wondered if there's a battery that doesn't just store energy for a few hours but can hold it for days, weeks, or even months? Enter the world of flow batteries, particularly the innovative zinc-bromine type developed by Redflow. Known for their ability to hibernate, these batteries can provide energy storage solutions for extended periods, making them perfect for seasonal storage needs.

Unlike traditional lithium-ion batteries, Redflow's flow batteries use zinc and bromine—materials not only abundant but also environmentally friendly. The technology involves complex processes like zinc plating and bromine creation, housed in modular setups that allow scalability depending on space and power needs. These batteries promise a reduced carbon footprint and a safer disposal process, given their water-based and fire-retardant nature.

As innovative as they are, these batteries do face challenges, particularly with temperature fluctuations. However, Redflow has smart solutions like adding heater pads to keep the batteries operational in colder climates. Furthermore, the company is pushing boundaries in manufacturing by aiming for automation, hoping to meet the high demand swiftly and efficiently. Redflow’s work highlights not just the functional capabilities of flow batteries but their potential impact on the future of energy storage.

Chapters

• 00:00 - 00:30: Introduction to Long-term Energy Storage The chapter discusses the emerging importance of long-term energy storage in the energy sector. While Lithium-ion batteries have been effective for fast frequency response and frequency-controlled ancillary services, the focus is now shifting to long-term storage capabilities. The narrator references a previous episode discussing Redflow batteries, highlighting their operations and significance. The chapter also mentions a visit to Redflow's R&D department and manufacturing facility in Brisbane to gain insights into their developments.
• 00:30 - 01:00: Redflow R&D Facility and Market Changes The chapter discusses the Redflow R&D facility located in Brisbane and mentions an event called the Fully Charged Show with six live shows worldwide, starting in Sydney, Australia in March 2023. It highlights shifts in the U.S. market, particularly the growing demand for non-lithium batteries, indicating maturation beyond traditional solutions.
• 01:00 - 01:30: Modularity and Long-term Storage Capability The chapter explores the advantages of modular batteries, specifically in energy storage solutions that require four to eight hours, and potentially beyond. It highlights the modularity of 10 kilowatt-hour batteries, emphasizing their self-contained design and scalability. The discussion covers the ease of interconnectivity and management, and it suggests that flow batteries provide a distinct advantage for long-term energy storage, challenging the conventional limitations of storage duration.
• 01:30 - 02:00: Technical Details of Redflow Batteries The chapter discusses the technical details of Redflow batteries, highlighting their energy storage capabilities. These batteries can enter a hibernation mode after being fully charged, operating on minimal energy consumption of a few milliwatts required for a microprocessor. This capability allows the batteries to remain in standby mode for extended periods, such as months, making them suitable for deep seasonal storage.
• 02:00 - 02:30: Flow Battery Chemical Processes The chapter introduces the basic principles of how a redox flow battery operates. It begins with a description of the flow battery mechanism, where fluid enters at one end, passes underneath the visible structure, and exits after performing its function during charge and discharge cycles. The essential nature of the electrolyte's movement is emphasized, as it flows through a separator membrane, the structural ridges facilitating this flow are highlighted as key components of the system.
• 02:30 - 03:00: Comparison with Other Batteries The chapter titled 'Comparison with Other Batteries' discusses the workings and components of a hybrid flow battery. It explains the technology is akin to a zinc plating machine, focusing on the electrode stack. The substrate used is a high-density polyethylene treated with carbon nanotubes to ensure electrical conductivity. Additionally, an extra layer of activated carbon is added on one side.
• 03:00 - 04:00: Temperature Effects on Flow Batteries This chapter discusses the role of temperature in the operation of flow batteries, particularly focusing on the enhancement of surface area for electrolyte contact. It mentions the use of graphite coating to promote zinc plating, comparing the graphite's feel to that of a school pencil. The chapter emphasizes how this graphite coating aids in the thick plating of zinc.
• 04:00 - 04:30: Improvements in Design and Manufacturing The chapter titled "Improvements in Design and Manufacturing" discusses advancements in zinc bromine batteries. It specifically explores the process where the channels of the battery can pick up about nine kilograms of zinc. The text explains the different components involved, such as the electrolyte fluid that is pumped through tanks and details the complexity of using zinc bromine electrolyte. Furthermore, it touches on the process taking place on the activated carbon side when voltage is applied.
• 04:30 - 05:30: Environmental and Supply Chain Factors This chapter discusses the chemical interactions within a flow battery, particularly focusing on the role of bromide in the electrolyte. When bromide interacts, it forms bromine, which is crucial in the process of electron exchange. This reaction is responsible for the observed voltage change across the cells within the battery. Furthermore, the chapter describes the formation of a thick red jelly-like substance as a byproduct of this chemical reaction, which is visually observable within the battery. This characteristic gives rise to the name 'red flow' as the battery is identified by the distinct color change resulting from the reaction.
• 05:30 - 06:00: Conclusion and Call to Action The chapter, titled 'Conclusion and Call to Action', discusses the chemical process involving bromine, particularly focusing on the creation of a bromine complex agent characterized by its thick and red appearance. The process involves the input of electricity from an external source, rather than generating electricity directly through a chemical reaction. The key takeaway is the explanation of how energy is effectively stored in the liquid phase, emphasizing the role of the zinc and bromine redox pair, a term used in chemistry. This summary simplifies the technical details and highlights the primary concept presented in the chapter.

Are Flow Batteries The Answer to Long-term, Seasonal Energy Storage? Transcription

• 00:00 - 00:30 but what's coming to the fall very strongly is longer term energy storage right so the Lithium-ion batteries have performed this fast frequency response frequency controlled ancillary services but the long-term storage is where our batteries really come right a few of you may remember an episode we did a few years ago we covered what redflow batteries are and we did stuff about how they work but I've now come to the actual r d department and their manufacturing facility here in Brisbane to see what is going on with red flow
• 00:30 - 01:00 now so this is the red flow r d facility in Brisbane and this is the fully charged show like the fully charred show then you will love our six live shows being held around the world in 2023 starting with Sydney Australia on March the 11th and 12th we've seen that the U.S market has matured to the point where they are there are projects that are asking for non-lithium Batteries they're not specifically looking for
• 01:00 - 01:30 four to eight hour and even Beyond energy storage solutions and that's where we have a definite part to play because our batteries are so modular 10 kilowatt hours and such a modular shape and completely self-contained the scalability is just up to how much space you've got right and how you interconnect them and how you manage it but then is that so that is a definite Advantage then that flow batteries have in terms of long-term storage I mean but you're still talking hours rather than like days or weeks or months no we can
• 01:30 - 02:00 actually bridge that uh days weeks months uh divide um our energy storage with the unique nature of the batteries it's able to go into a hibernation mode you can fully charge the battery and then put it into hibernation mode with zero or a few milliwatts of microprocessor alive yeah the rest of it is discharged wow I knew we could have those in standby for months deep seasonal right duration right and then
• 02:00 - 02:30 come out of that hibernation and discharge the power the red flow battery work just so that I understand it the fluid comes in one end of that it goes through underneath what we can see here it's effectively through all that and out the other side as it's charging and discharging that's correct yes so in terms of it being a flow battery the electrite has to flow and the separator membrane has exactly those I see so that's the help direct so those are all ridges so they're perhaps flowing in
• 02:30 - 03:00 between those blue lines correct in what we call a hybrid flow battery it is actually a zinc plating machine and how that works on our electrode stack this glossy black substrate yeah is the same high density polyethylene but it has been doped with carbon nanotubes wow so that it's actually conductive electrically conducted between the top and the bottom on one side we add an additional layer of activated carbon and
• 03:00 - 03:30 what that does is it just massively increases the surface area right for the electrolyte to be in contact with on the other side we coat it with graphite if you rub your finger on it it's like the school pencil oh I see you get the you get the black pickup yeah yeah yeah well now the graphite actually facilitates the plating of the zinc right and once the zinc is plated as you noticed quite thickly yeah in those
• 03:30 - 04:00 channels then an entire stack will pick up about nine kilograms worth of zinc wow okay on the other side of the electrode this is where a different kind of magic happens we start off with the electrolyte so that's the fluid that's being pumped through and that's correct in the tanks right yes this is the zinc bromine electrolyte it has a few other things in it as well and what happens is on the activated carbon side when it's got the voltage applied across
• 04:00 - 04:30 it the bromide that is in the electrolyte interacts and forms bromine right and that's where the electrons are given off or or received to change that compound which is what gives you the the voltage change across the cells and it actually forms a thick red jelly-like substance we can see a little bit of it over here inside there all right resting on the bottom is correct okay and that's actually where red flow gets its name it's a flow battery that once the
• 04:30 - 05:00 bromine is released it forms this bromine complex agent which looks thick and red yeah and and because that's the thing I was thinking as you were explaining that well I was going hang on where's the electricity but you have to to put the electricity in from an external Source it's not making electricity from this chemical process it is storing it effectively in the liquid it's very very simplistically one of the reasons why the zinc and bromine redox pair and that's a chemical term
• 05:00 - 05:30 for reduction in oxidation the way that it plates and unplates or turns from one form of bromide into bromine why that is so beneficial for a battery is that in part of the process it gives up two electrons whereas other chemistries only give up one electron so effectively we are getting twice the bang for buck right which means that on a size for size basis a zinc bromine flow battery can achieve the same amount of energy storage
• 05:30 - 06:00 as other flow battery sizes twice as big bright I see so you're right okay so you're effectively half the size of another float battery that would could produce the same amount of energy that's just one of the aspects there's several other aspects that go into it but that's a quite a straightforward way of understanding that the bromine and zinc actually work really well together right to do what a battery needs to do one last thing because I'm experiencing this at the moment it was the the impact that heat
• 06:00 - 06:30 has so our flow battery is affected by heat in the same way oh they are right they are affected by heat because it's a it's a chemical process right maybe not as drastically as as the high energy density batteries yeah but definitely there is a heat effect we find that there's the zinc bromine flow battery is most optimal at 30 degrees Celsius right it has a very we call it the umbrella curve at 30 degrees Celsius it's at that pointy bit of the umbrella
• 06:30 - 07:00 but it falls off a little bit either side of that right for the flow battery our biggest problem with temperature is the low end right what happens is because it's an aqueous solution and because of this bromine complexing agent that we add it becomes too viscous if it's very cold if it's very cold it's very difficult to get a thick sludgy liquid which our pumps homogenized they froth it up like a milkshake but to get that to then flow through these to the
• 07:00 - 07:30 very channel so the cold end is is a limitation for flow batteries but we do have a solution we put a heater pad underneath right and we gently warm it up right as long as it's about 15 degrees Celsius everything works which is pretty that's pretty right yeah on the high end our batteries are quite happy going up to 50 degrees 5-0 the battery can be fully operational as long as the battery itself doesn't exceed 50 degrees Celsius right or the electrolyte itself doesn't exceed 50 degrees Celsius
• 07:30 - 08:00 so we've seen the elements needed to create this Battery Solution how does it compare to what we saw five years ago so this I'm so impressed with this having seen the the older versions of which you've got still got some here this is so much simpler I mean I can tell this is you know a really streamlined version absolutely but it's essentially the same idea what's going on inside is the same yes yes the
• 08:00 - 08:30 biggest change has been on what we call the stack the top part over here uh if you were to open the stack up if you were to take a cross-section through it you would see plates right that look like cells inside a lead acid battery right and that's essentially how this battery operates as it has 30 cells each generating about 1.6 volts so 30 of them together is giving us 48 volts right we've had to stay with the same surface area inside the stack as on the previous version but we've changed
• 08:30 - 09:00 the geometry a bit by changing the geometry we've been we've been able to flatten it we've been able to make it only out of plastics right whereas previously it was bolted together with two compression plates a lot of nuts and bolts a lot of manual assembly this has now been redesigned towards automated manufacturing eventually we will have an automated manufacturing line putting these together major advancement is what we call the battery controller on the front of the box here this is currently version 12 we call it the mark 12 right
• 09:00 - 09:30 everything has become solid state Electronics this controller can adjust the voltage levels to mimic other types of batteries right so this battery could be put in alongside a aging lead acid battery bank right and the controller for the the battery controller appears like a Lithium-Ion battery so a lot of third-party inverters and Battery
• 09:30 - 10:00 converters you just put it on the lithium-ion battery setting and it's pretty much happy it does it right yeah we've increased its manufacturability we're aiming towards automated manufacture we have reduced the component count we've reduced the amount of manual work to assemble the battery so we really are aiming for high volume production right and that just to explain because the tanks are basically we can't really see them but they're under here this is where the correct the fluid is there right yes there's two tanks they hold about 100 liters of the electrolyte right
• 10:00 - 10:30 um just out of interest when the stack is fully charged it gains about nine kilograms of weight while the zinc that gets extracted from the electrolyte and plated into the battery wow wow the electrolyte itself is aqueous it's water-based yeah and the bromine in it is a known fire retardant right so if this was to be involved in a fire then it would spill it would rupture it would
• 10:30 - 11:00 leak but to clean it up it's just sawdust dirt any type of industrial mock-up right a process you can clean it up and dispose of it in the normal Municipal garbage it is not a so it's not a toxic it's not a toxic substance but those Source minerals the zinc is readily available especially here in Australia right and the other mineral or the other element bromine it's a waste byproduct from the production of salt right when they are forming salt in salt pans they
• 11:00 - 11:30 just let the bromine walked away right they're not interested in recovering it right so that is a potential future stream to capture that yeah at the moment we get a lot of our our electrolyte from the Middle East area around the Red Sea right where they do the desalination because there's the quantity of salt so then you don't think about when you hear about desalination you think about the fresh water you get out of it the salt's got to go somewhere oh well that's all we've got time for I
• 11:30 - 12:00 really want to thank the people at redflow who helped us organize this it's you know I had to fit in with their date they're really busy they cannot make enough batteries that's the key message one of the things we didn't really talk about but you know if you if you want to uh if you want to order a red flow battery there's a bit of a waiting list they are churning them out as fast as they can they are really popular really successful thing great to see what they're up to anyway that's all please do subscribe please tell your friends about the fully charred show have a look at the patreon link if you're overmined and as always if you have been thank you
• 12:00 - 12:30 for watching