Each city only needs 2 hours of grid storage in batteries, and after that the local pumped hydro should take over. This should be done with the cheapest safest grid batteries possible. (Lithium batteries in a desert somewhere need to waste maybe 40% of their energy just air-conditioning them so they don’t overheat and cause a fire!)
But because we only need 2 hours of storage from batteries until the pumped hydro kicks in, the options below are already economically viable. There are dozens of competitors in each category – and a new one seems to pop up every few months. My main point is with this page is that with batteries for 2 hours and pumped-hydro for up to 2 days – we already have the all the technology we need to Electrify Everything and get off fossil fuels forever!
This page will also debunk the myth that there are not enough minerals or metals in the world to complete the energy transition because of the storage requirements.
- “Free” batteries if we repurpose old EV batteries for the grid!
- Sodium Batteries have abundant cathode choices
- Sodium batteries sign a big deal in Australia
- Iron Batteries
- Solid state batteries
- Massive growth ahead – by 2030 America with have 15 TIMES the battery factories!
- Liquid flow batteries
- Layers of liquid metal floating on each other. What the?
- Thermal batteries
- Battery youtubers and podcasters
- Future Battery Chemistries
- Batteries I would avoid due to limited resources
“Free” batteries if we repurpose old EV batteries for the grid!
EV’s are considered ‘dead’ when their battery capacity degrades down to 80% as this cuts the car’s range too much. However, that extra capacity is fine for the grid! Companies take the battery and slot it into the standard warehouse slot for that car model battery make. There are issues – and a main one is transport! Because the battery pack is so heavy reusing these batteries this way would probably only work if the EV were stripped and the battery reused in the same city. Otherwise transporting it might make it cost as much as one of the new grid batteries mentioned below!
Sodium Batteries have abundant cathode choices
SODIUM FROM SEA SALT
Today we mine a lot of sodium from other mineral combinations. But we’ve been harvesting it for thousands of years because it is sea salt. There’s 38 Quadrillion tons in the oceans. At an Energy density of 100 Wh/kg, that’s enough sodium to store the world’s electricity use for 152,173 years! Or to put it another way, to store a WHOLE YEAR of the world’s electricity would take just 0.0006% of the ocean’s salt. Or yet another way – a world of 10 billion people could each get a (purely hypothetical) 5 million tons of sodium each. And it can be recycled. We’re not going to run out of sodium!
NOW IN THE MARKETPLACE
While there is still enormous R&D into new sodium batteries, sodium is now in industrial production and growing every year. Here are some 5 manufacturers as of May 2023. (Google it again if you’re reading later.)
MANY BENFITS
Sodium batteries are thermally more stable and safer than lithium. They are shipped at zero charge which makes for safer shipping than lithium. And they are about a third cheaper than lithium.
NO RARE EARTH’S OR METALS – A VARIETY OF SUPER ABUNDANT MATERIALS TO CHOOSE FROM
And they require no rare earths – and no lithium, cobalt, graphite, manganese, copper, or nickel. So what do they use? There are actually too many options for me to document here. I’ll pick my favourites. As I discuss the options below, don’t lose sight of the forest for the trees. I’m not predicting any one of these feedstocks must be a winner. Rather catch the vision of a big periodic table of elements and a truly enormous variety of chemistries (sometimes tweaked by nano-tech) to give us incredible options.
SODIUM IRON-PHOSPHATE
Remember the Lithium-Iron-Phosphate battery that Tesla is building now to reduce their reliance on rare-earths and expensive metals? Here’s the sodium version – and yes – it’s iron and phosphate.
“Sodium Iron Phosphate (NFP or SFP): Similar to lithium iron phosphate (LiFePO4) in LIBs, sodium iron phosphate batteries are known for their safety, long cycle life, and thermal stability.”
Ajay Gautam (Oct 2023)
HARD CARBON
The enormous category of ‘hard carbon’ seems quite promising, with many different precursors from “animal waste and sewage sludge” (Medium April 2022) and especially hazelnut shells! I’m excited by the hazelnut shells report as it indicates they may be really cheap and easy to process -not needing high temperature processes or acids. Just a little wash, and they’re ready. There is over a million tons of production of hazelnuts a year – and about half of that is the shell. (Andrea Fuso May 2021 – Point 1.) That’s 500,000 tons of hard-carbon feedstock annually that we’re currently just burning in boilers.
Bio-charred agri-waste is another feedstock for Hard Carbon – Dario Alvira et al (Nov 2022). Annual agri-waste is somewhere in the tens of billions of tons a year.
PRUSSIAN BLUE
Prussian Blue can also be made from more abundant materials – and interestingly it seems the more abundant hexacyanoferrate (FeHCF) actually works better than other cathodes from less plentiful materials.
Sodium batteries sign a big deal in Australia
The launch of the “plug-and-play” GridPack comes just six months after the two sides signed a joint venture agreement to commercialize Fraunhofer’s Cerenergy sodium alumina solid state battery technology, which relies on sodium ions commonly found in table salt and avoids using rare and expensive metals such as lithium, cobalt, graphite and copper. Altech Batteries said the technology eliminates exposure to critical metal price rises and supply chain concerns. Fraunhofer has estimated that the cost of producing Cerenergy batteries should be about 40% cheaper than lithium-ion batteries, which currently dominate the global energy storage market.
The joint venture is commercializing the sodium chloride battery technology, with plans to construct a 100 MWh production facility on Altech’s land in Germany. It is anticipated that the facility will produce 10,000 individual 10 kWh Cerenergy battery modules every year to provide grid storage solutions to the market.
While the development of the manufacturing facility continues, the companies have now launched the design of the 1.0 MWh GridPack. Each GridPack, to be housed in standard shipping containers, will feature to 20 individual 60 kWh battery packs connected to a power management system. Each unit will have a distinct rating of 600 V (DC) and 100 amp hours and will be able to be arranged in a series to achieve the required rating of several thousand kW for grid functioning.
Altech said the GridPacks are modular and stackable, which reduces their footprint, and have a “plug-and-play” feature that makes them easy to install in remote locations. The company said there are no moving parts such as cooling fans and the batteries can operate in any climate without need for thermal management – a key advantage of sodium-alumina solid state batteries over lithium-ion alternatives.
With a projected lifespan of more than 15 years and unlimited cycling, Altech said it is confident that the technology will become the “preferred choice” for companies seeking a reliable and long-lasting energy storage solution.
“These 1 MWh GridPacks will offer significant benefits for the fast-growing renewable energy and grid storage sectors,” the company said. “They are an excellent means of stabilising the grid by providing a source of backup power during periods of high demand or when renewable energy sources are not producing at capacity. They are also a cost-effective solution for storing and distributing renewable energy across a variety of applications, including grid-scale storage, microgrids, and electric vehicle charging.”
PV Magazine April 2023
For more see the wiki or this episode.
Iron Batteries
Iron is even more abundant than sodium! The sound-byte for the next battery? It’s still in development, but essentially rusts and then de-rusts the battery in a chemical solution.
Solid state batteries
I find myself becoming more sceptical about solid state batteries. But this is more for EVs and not grid storage – unless there is a truly miraculously cheap technology breakthrough. And with the way wind and solar have come down tenfold over the last few decades – we do live in an age of miracles. Who knows?
Massive growth ahead – by 2030 America with have 15 TIMES the battery factories!
By way of hypothetical comparison only, it means that America itself could supply all new cars with enough batteries to be 100% EV. (Note – this is for illustration purposes. I am not claiming America will stop importing cars and build all their own!) These batteries will of course be split between their EV, household, business, and grid utility sectors.
Liquid flow batteries
Normal batteries are relatively small and you build hundreds of them in a battery pack for an EV. But liquid flow batteries take a completely different approach.
The more widespread Li-ion batteries encase all three of their main components – an anode, a cathode, and a chemical solution called an electrolyte that allows for the flow of electrical charge between them – in one cell. A Li-ion battery can contain one of these cells, or it can contain several, but the key is that all three components of each cell are encased together.
Flow batteries, however, are separated into two tanks of liquid electrolyte – one tank of positively charged electrolyte, and one tank of negatively charged electrolyte. A conductive membrane sits between the two storage tanks. When the battery turns on, positive and negative electrons flow back and forth through the membrane, and as they circulate, they generate electricity.
The amount of electricity a flow battery can generate depends on the size of the tanks, so if you need to scale up and store more energy, you can swap them out for bigger tanks, without replacing the membrane.
What’s Watt
Layers of liquid metal floating on each other. What the?
- Yes, just like when you pour a B-52 cocktail and the different liquids sink or float to their layer, these metal batteries sit in liquid layers on top of each other. Only not as tasty! 😉
- They are a sub-category of Molten Salt Batteries – see wiki.
- No need for membranes and separators
- 80% efficient
- Higher tolerance for overcharging or over-discharging than lithium
- Much slower degradation and longer lifespan. EG: Deep-cycle a lithium battery every day for 2 years and it will lose 20% of it’s capacity. This liquid metal battery can be deep cycled every day for 20 years and lose 5 to 10%!
- Made up of liquid calcium anode, molten salt electrolyte, and solid particles of antimony for the cathode. Antimony is only 0.2 to 0.5 parts per million of the earth’s crust – but is a by product of mining copper and silver and other metals. For this reason I’m not yet prepared to dump it in the “Batteries to avoid” section below. Antimony cannot be that hard to get as the materials are expect to be 40 or 50% the cost of lithium batteries!
Thermal batteries
The last category of energy storage is not necessarily about storing electricity as such – (even though some can). It’s more about storing heat – sometimes to replace truly enormous amounts of coal and gas burned just for industrial heating! For details on this amazing technology please click here.
Battery youtubers and podcasters
“Undecided” with Matt Ferrell
“Just have a think” with Dave Borlace
“Energy Insiders” podcast
“The Regeneration” on energy storage
Future Battery Chemistries
Big Battery is pouring so much R&D into new chemistries I really wonder if lithium will be king in a decade or so? There are dozens and dozens of new chemistries Big Battery are researching now, like lithium-sulphur. But will we even need lithium in 20 years? Or instead will batteries be nano-yolk triple capacity, aluminium-sulphur, aluminium-air, or aluminium-graphene? Aluminium is 1000 times more abundant than copper – and it has some super-battery potential IF they can solve various chemistry hurdles. If you want to follow along as the industry works through these various chemistries, try the battery playlists at Undecided and Just have a Think – two of my favourite youtubers.
Indeed – here are 5 of the above batteries summarised in the one 13 minute youtube
Batteries I would avoid due to limited resources
Just as a precaution I might gradually compile a list of resource scarce batteries. When Sodium and PHES and various thermal batteries can supply all the storage we need – why accelerate the depletion of resources that other industries might need more?
Zinc is expected to peak and decline later this century. For that reason I cannot recommend the Zinc Bromine Liquid Flow battery (Undecided Dec 2022)
Eclipse Now 
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