The World's Largest Battery Isn't What You Think

Published 2022-04-19
Exploring the world's largest batteries. Old tech could still be the future of energy storage. Go to to sign up for free. And also, the first 200 people will get 20% off their annual premium membership. Because of the intermittency of renewable energy like wind and solar power, storing large amounts of electricity is a necessity for the decarbonization of our energy system. However, we still don't have enough batteries to compensate for renewable energy slumps across the planet. When thinking about the biggest utility-scale energy storage installations, a huge cylindrical lithium ion battery powered light bulb may go off in your head. But what if I told you the world’s largest battery taps into water rather than lithium? Can an old technology, even one still learning new tricks, be the answer? Let’s see if we can come to a decision on this.

7:04 Clarification - $100/kWh is the build cost.

Watch This Battery Breakthrough Lets EVs Charge in MINUTES

Video script and citations:…

Follow-up podcast:
Video version - /channel/UC4-aWB84Bupf5hxGqrwYqLA
Audio version -

Join the Undecided Discord server:

👋 Support Undecided on Patreon!

⚙️ Gear & Products I Like
Tesla and smart home gear:

Great sustainable products for your home:

Undecided Amazon store front:

Fun, nerdy t-shirts:

Abstract Ocean Tesla Accessories:
15% Discount - Code: "Undecided"

Jeda Tesla Wireless Charger/USB Hub:

Tesla Referral Code:
Get 1,000 free supercharging miles
or a discount on Tesla Solar & Powerwalls

Visit my Energysage Portal:
Research solar panels and get quotes for free!

Or find community solar near you:

👉 Follow Me




📺 YouTube Tools I Recommend
Audio file(s) provided by Epidemic Sound



I may earn a small commission for my endorsement or recommendation to products or services linked above, but I wouldn't put them here if I didn't like them. Your purchase helps support the channel and the videos I produce. Thank you.

All Comments (21)
  • Brucec 95
    Seems like desert pumped Hydro would benefit from adding floating solar panels which help reduce evaporation and keeps the panels cooler.
  • Jason Ta
    This definitely reminded me of an article by low tech magazine where they talked about using compressed air for home energy use. It's always interesting to see what we can do with older tech to deal with modern problems
  • Bernie Chmilar
    Great video Matt!
    I think we need to maximise the use of the simpler solutions that you covered along with other low tech ones in order to save lithium and other materials that have to be mined and processed for more important uses. Processing all those elements requires a lot of energy and comes with a lot of environmental baggage.
  • Doug Carr
    Love it. The more these other technologies can play a roll the more lithium can be reserved for transportation. As you said, lithium batteries shine for short duration storage with a quick response time. Making them most useful when paired with other storage technologies.
  • Schizoidman
    Hey Matt! It is incredible how your videos are becoming more and more interesting as time passes by. This video is one of your best in my opinion. I left Discord. Sorry for not being around your channel anymore. You are a great guy, always answering even when people are not friendly. Still uncertain of why this channel is called "Undecided". 😆 Congrats!
  • Luke
    Matt, your powerfully-presented presentation puns pack a pretty impressive punch, as such improving your persistently pleasing presentation is practically impossible. Your persona and presence are a plus and you’re persistently on-point. Props. applause 👏
  • Paul Williams
    Interesting topic and pleasant presentation. There's still a recurrent problem with units here such as at t=576 "Projected Li-ion capacity increase = 28GW/year". KW, MW and GW are units of *power*, for example the instantaneous output from a storage plant. KWh, MWh and GWh are storage *capacities*. GWh/year is an annual increase in power storage capacity. Any given storage plant needs rating in terms of three things, power eg in MW, capacity eg in MWh and storage efficiency as a %. Sorry for the nitpick!
  • RN1441
    Thank you for making this video, as storage really is a missing link in the renewable energy supply chain. It seems that many countries and regions have in recent years dramatically scaled up their renewable energy production but done nearly nothing in comparison for renewable energy storage leading to reliability and cost problems.
  • Jonathan Langlois
    I absolutely love your take on pumped hydro. It seems that every time I point out on social media that niche solutions aren't the answer, I get a lot of hate. A lot of peoples have yet to figure out that viable solutions need to be scalable to industrial scales.
  • Steve Martin
    I'm taking my 4th Solar online class right now, and this one is called Battery-based solar (PVOL203). This was a great video I will share with the class. Thanks, Matt.
  • Rick Rys
    Lithium Ion is great for high power, but costs a lot to store a lot of energy. Great presentation Matt. In New England I can image that we use offshore wind in combination with 35GW of Quebec hydro operated to store energy. Not a trivial problem but perhaps our future.
  • Adam Smith
    I would love to see an update on flow batteries. They take up a bit more space, but I was under the impression that they are reliable and far cheaper per unit of stored energy. There is even a company that makes shipping container batteries that use salt water (or something close to it) as the electrolyte.
  • Tord Lindgren
    personally I am a fan of the iron/salt water batteries in combination with graphene capacitors. It's simple, elegant and can work pretty much everywhere. and the materials are both cheap and abundant. graphene capacitors are still struggling to be mass produced though.
  • Theodore Haskins
    So thank you for posting this video, as I had not really thought too about these methods of producing and story energy, and so I find this to be quite interesting, and a real eye-opener too. Cheers!🥂
  • Jaco Hollebrandse
    I also find the idea of using the sea as a pumped storage facility very interesting.

    Damming of an area and drain it. Draining it below sea level (by pumping) gives the same energy potential as filling above sea level, but is far less risky, because a dam failure refills the emptied area, instead of causing a massive wave.
  • W.M. Abel
    Grand Coulee Dam is looking to do exactly that with Banks Lake, next to it. They have been doing it, to a degree for years, but they're looking at putting in a couple new big tunnels specifically for generation. Fascinating stuff, several billions in upgrades lately and still working on it. Keep up the good work, Matt! You rock.
  • bruce hain
    94% - that's an amazing figure. They used to run whole railroads that way. In Mexico starting in Cordoba and running up a big slope through Maltrata. I'm estimating about 50 miles. It was implemented in the 1920s and was gone by the time they introduced the longer, heavily tunnel encumbered alignment in use now about 1985. Now you would just build an enormously long, straight tunnel under the old line.
  • A Canuck
    What a terrific analysis and comparison of the three most well-understood electricity system energy storage technologies. The efficiency of your analysis of these technologies is likely about as close to 100 percent as anyone can manage. Thanks.
  • David P
    I must say, your channel is awesome.. I wish you could do more content on other issues.. I know one man can only do so much... I for one thank you for your time and efforts...