Engineering with Rosie - 2025-12-24
Buy The Book: The Ultimate Guide to Rebuilding a Civilization at Hungry Minds and use promo code ROSIE10 for 10% off https://bit.ly/EngineeringwithRosie Do we really need all these long-duration energy storage (LDES) technologies to hit the net-zero target? We might be better off reducing emissions as fast as possible using our existing tech; rather than getting to exactly zero electricity emissions by a certain timeline. @HungryMindsArt #thebook, #hungrymindsbooks, #howtorebuildcivilization, #hungryminds, #hungrymindsthebook, #christmasgift ____________________________________________________________________________________ 📌Timestamps: 00:00 Introduction 01:27 Daily Storage vs LDES: When Does LDES Come In? 06:35 Pumped Hydro 07:52 Flow Batteries 09:05 Iron-Air Batteries 09:41 Compressed Air Energy Storage (CAES) 10:27 Gravity Energy Storage 11:39 Hydrogen 15:36 How Much LDES Do We Actually Need? 17:17 What about the last 2 - 15 percent? ____________________________________________________________________________________ 🌱 Join the Engineering with Rosie Patreon community to help develop our channel here: https://www.patreon.com/engineeringwithrosie You'll join our Patreon-only chat/Discord server to discuss and suggest topics of interest! ☕️ Or you can support by buying me a coffee here: https://www.buymeacoffee.com/engwithrosie ⚙️The Engineering with Rosie team: Rosemary Barnes - Presenter, Producer & Writer Javi Diez - Graphics & Editor (https://www.linkedin.com/in/javierdiezsuarez/?locale=en_US) Jae Chong - Research & Production Assistant __________________________________________________________________________________ Sources: IEA 2024 – Managing Seasonal Variability of Electricity Demand and Supply; Scientific paper analysing mismatch components: https://www.sciencedirect.com/science/article/abs/pii/S0306261922002008 https://hydrogen-germany.de/en/news/seasonal-electricity-storage-in-the-form-of-hydrogen-ready-for-scale-up https://www.linkedin.com/feed/update/urn:li:activity:7401453188190584832/?updateEntityUrn=urn%3Ali%3Afs_updateV2%3A%28urn%3Ali%3Aactivity%3A7401453188190584832%2CFEED_DETAIL%2CEMPTY%2CDEFAULT%2Cfalse%29 #energytransition #energystorage #longdurationenergystorage #netzero #batteries
"Getting most of the job done fast"
So much sense in one little phase.
Thanks.
Getting most of the job done cheaply.
“Slightly-less-obviously flawed” is excellent, and accurate.
This video only covers storage of energy meant to be turned back into electricity, but a lot of the long duration energy storage projects in Scandinavia are simply turning the energy into heat which can be pumped into district heating networks when needed during colder months. I would love to see that covered in a future video.
the super cheap days to weeks thermal energy storage for low and medium grade heat does start to plug a lot of holes with variable demand instead of electricity storage once you start electrifying things, since so much of our energy demand is low and medium grade heat. It does only work for industrial or district heating systems though since most of the direct thermal storage systems don't scale down very well, which means you can't use it everywhere unfortunately.
This is true - around 80% (4/5ths) of UK domestic energy requirement is for heat and hot water. Much better to have local heat batteries heated during summer and autumn to power us through winter when the wind might not always blow.
Yes - that would be interesting. Also consider ocean (wave, currents, tides, saline) energy developments along with geothermal in helping bridge the solar / wind gaps.
Yes, thermal storage is another great application. We will need a lot of industrial heat, and there are very cheap solutions being developed to store surplus electricity as heat that can be released in a controlled fashion to power industrial processes. This may not help with seasonal storage, but it will help with storage on the order of a few days. For seasonal variations, I think we will just overproduce power and try to get creative with how we use the surpluses.
Using thermal mass to produce electricity is also possible, but has not been given a lot of attention. At the YouTube channel Two Bit DaVinci, that guy talks about a start-up, Exowatt, using technology to store solar energy in the form of heat which is used to power a sterling engine to produce a consistent supply of electricity. It's still in the developmental stages, but it appears promising because of its relative simplicity and use of conventional technologies.
Glad you're doing the heavy lifting for us, Rosie. You clearly understand the gravity of the situation.
We all get a charge out of your videos.
Best comment, thank you for taking the time to pun!
Rosie really does make complex topics feel approachable and engaging. It's awesome to see someone breaking things down so clearly for everyone.
Rosie does not know what she is talking about. She is out of touch with reality.
One aspect you don’t cover is heat storage. Especially here in Europa, a lot of energy goes into heat, for home heating as well as industrial heating.
Totally agree. It also coincides with the time of year when solar output is lowest.
There are two kinds of thermal storage. Heating buildings or industrial materials when electricity is cheap, and benefiting from that heating hours later when electricity is more expensive, is in the category of schedulable demand, so at least the broader category was mentioned in passing. But there's also heating up rocks that are already very hot, and using the heat later to drive steam turbines.
That's a really good point about heat storage being crucial, especially in colder climates. It would be awesome to see that covered in a future video, as it's a huge part of the energy puzzle.
Wouldn't even make it more sense then to produce even more super cheap solar, and just pump it into hydrogen production? Sadly batteries have won the race for cars, by my idea always was that we could power cars, trucks and heating with that gas produced from overflow sun power. But guess it is less efficient then batteries nowadays. Even more so when yo convert it to methane in a bio reactor. On the other hand, sunny countries like Spain, Morocco or Australia can produce solar power for 0,01 Dollar/Euros per Kilowatt.
Very good point.. Northern Europe (along with much of the northern hemisphere) has a disproportionate energy use for heating, but most of the focus seems to be directed towards electricity generation...
A particular topic that seems to get very little attention is heat from wind power (kinetic to thermal, via heat pump, friction or other route), which could operate on a district or even individual residential basis for producing heat. If anyone knows of any resources on this, please share!
NZ with so much hydro means every hour of sunlight, every rotation of a wind turbine means less water through our dams so any renewable systems added automatically comes with grid storage.
I've got to get to NZ and make some videos there! It's crazy to me as an Aussie how dramatically different our energy systems are, with totally different challenges and opportunities.
Not really.
First, river valley fed hydro has limits on how much it can be used as storage. There are always many stakeholders down river from the dam that depend on a continuous water flow, both environmental and business. It’s not feasible to say, ‘plenty of wind today, shut off the dam flow to store water. ‘ without wrecking the river ecosystem and local economics.
Second, are the inevitable droughts, recently made infamous in NZ. There are both seasonal low flows and periodic droughts, the last of these ran the NZ leader off after she foolishly killed off much of the gas fired power which had traditionally run NZ in droughts.
Hydro can do a little storage but it can’t be a guaranteed, year round backup for intermittent power.
@N@Czeck0-u1kAnd that’s where geothermal’s usefulness kicks in
@John-kg5pv. Geothermal supplies about 20% of NZ generation, and has been around since the 1960s and 1980s, total NZ capacity about 1200 MW. Globally, Geo supplies about 0.3% of global electricity. There’s a reason for that. It won’t magically expand.
So far the reverse appears to be the main issue. Drought causes high power prices and water scarcity and low lake levels can result in environmental damage.
17:35 "Who cares about that 2 to 15% right now?"
Exactly. We need to put more emphasis on this. Everytime someone says "But we can not do 100%", we should answer "Ok, you are right for the time being, but why do you then block to go to 85% as fast as possible to at least have 85% clean energy?"
Because their agenda is not to get the best result, but to sabotage renewables.
it's not about grid demand alone, it's about the transition away from FF where FF are used for thermal energy at industrial locations, that is a huge amount of energy compared with daily grid demand. there will be crossovers b/w off-grid and on-grid, electrified and non-electrified processes.
@alastairleith8612 Thats what I said. Then we deal with it later.
The problem is that 85% is exceedingly expensive and the last 15% is off the charts. It means we have to maintain 3 separate systems at all times. The dispatchable source, the collection source (wind/solar), and the storage. In sunny places like Phoenix, solar can really offset enough fossil fuel costs to pay for itself, but the more you add, the worse the economics get.
Of course, it's much worse in the rest of the country, where there isn't that much sun. Oh, but what about interstate transmission lines from the desert to those areas??? Again, this just makes the economics worse, not better.
But it's Ok, the US has lots of natural gas and gen. IV nuclear is on the way to replace it.
@chapter4travelsThese integration costs are not that high per kWh and smaller than the cost difference with extremely expensive nuclear.
In Norway we have a fantastic storage option that i guess you didnt think about in Australia. Since we use a lot of heating for our homes and businesses we can convert electricity to heat, then store it like that, and use it whenever we want. Almost like storing hot tap water, but for heating houses. Storing the energy after convertion is far cheaper then storing electricity or converting it back from some form to electricity. Heat can be stored in the building concrete or the rock underneath and tapped out simply by closed loop water pipes and a pump. Energy convertion is done by a simple dirt cheap heating element almost without energy losses, or with a heatpump for larger systems and higer efficiencies. 400% efficiency, or more precicely 4:1 SCOP is common.
Good on you Rosie, it is really important to hear the voices of reason above the drone of despair or denial.
Considering she included the "gravity battery" I really wonder about her qualifications for investor advice.
This is why climate change gets so much pushback. It’s presented in a way that you can’t be happy. It’s either total despair or denial.
No one wants to believe something that makes them feel horrible.
We all want to be capable of taking action to solve the problem. And we don’t want to be told we are the problem.
That never works.
@teresashinkansen9402she also dismissed it for most applications.
@teresashinkansen9402she then said it wasn't viable later
@Sean-zf6nf Why even mention it? Reduces her credibility.
Well said , Rosie. "The perfect is the enemy of good."
That is what my least favorite corrupt politician said to justify his misappropriation of funding and choice of less competent bidder fof contracts.
This guy 4-8 Xed the cost of everything he was involved in and we got much worse products than what was available on the open market, while he pocketed masive kickbacks.
Or another way to say it is - don’t let people block doing anything just because the solution doesn’t solve the problem 100% and instantly. 😅
This is the way- Toyota chose this path (hybridization over full electrification) BEFORE the rebates were dropped. With massive government backing this (full shift away from non-renewables) MIGHT have been possible, but with that withdrawal, the whole industry is starting to see the wisdom of hybridization- it still checks the boxes without contorting the landscape and economy. This puts companies like Tesla and friends in a tough position, now having to simply justify their version of an exorbitant, unnecessary existence that's wasteful of the environment. One fully electric vehicle has enough battery for 8 hybrids, and when the average driver travels less than 30 miles a day, the 250+ miles of battery in full-electrics suddenly become embarrassingly wasteful.
No one in their hearts wants greenhouse gasses, smog, and other pollution that ICE brings- and almost no one actually needs 300 miles of rare-earth metals mined out of the ground for what might end up being a fancy right of refusal capability. Moderation, middle-ground... I know, I know, those terms don't sound edgey.... but this is the way.
@danstermeister 😂 is all that blather deserves.
@danstermeister You state: " no one actually needs 300 miles of rare-earth metals mined out of the ground for what might end up being a fancy right of refusal capability".
Here you are ignoring what is required for the fossil fuel driven alternative. A low carbon economy requires a hundred to a thousand times less mining than one dependent on fossil fuels. 100 times if you include overburden rock and 1000 times if you focus on the actual ore/ end product. Mild hybrids still burn lots of fossil fuels - they are not helping to deliver a low carbon economy! But protesting about "300 miles of rare-earth metal mining" you are letting perfect be the enemy of good. Yes we need to mine stuff for BEV but the level of mining required is sooooo much less than that required for the fossil fuel driven world.
6:50 There’s no needs to get rude! 😝🤣
Not just pumped hydro, but traditional hydro too. When renewables are producing well, the draw from the dams is less, and so they stay fuller. i.e. we can get to the end of summer with fuller dams, which can help us get through a dry winter. No extra pumping required.
Pumped hydro is the icing on the cake - providing a lot more flexibility, and also shorter-term storage options (e.g. you can pump/release on a daily cycle)
That's a really solid point about traditional hydro's role in seasonal storage. Having fuller dams heading into winter sounds like a huge advantage, and pumped hydro adding that daily flexibility makes the combo even stronger. Great explanation
In many places dams play as important or more important role in water supply downstream issues than energy production.
Absolutely nothing incorrect in what you've said.
I'd like to add that rainfall is becoming increasingly unpredictable. The UK has had major problems this summer with dams running close to empty.
Keep in mind storage efficiency, batteries are (80-95%), followed by Pumped Hydro (70-80%), while Electrolysis-Hydrogen-Fuel Cell systems are lowest (30-50%). Also batteries and fuel cells have limited lifespans and need to be replaced and hydrogen is very prone to leaking.
Hydrogen might make sense for very long duration, as the efficiency is less important for this and the infrastructure for actually storing the hydrogen is cheap ( an old gas well has a huge capacity). The big advantage is that you can pay for the infrastructure for making the hydrogen by seeking hydrogen to chemical plants so the cost of the energy storage is just making your hydrolysis plants reversible and an old natural gas well.
CAES sits about 75-80 and can be scaled almost indefinatly using cheap steel tanks.. making anteresting project to analyse on cost.
Highview are building Li-Ion / Caes(Liqified ) systems. Currently they have a 6hr project and a 300MW x 12.5hr !! project in the pipeline,
Efficiency isn't super relevant if you have access to abundant and very cheap energy when charging the battery.
Round-trip efficiency matters on storage of renewable energy because the forecasts are that a massive amount of land will already be needed for renewables. Casually doubling that area and d cost is not to be taken lightly. The 8.2 billion people on earth are close to using up the solar carrying capacity available to us if we include agriculture and forestry.
@peteinwisconsin2496 it matters for storage that is used regularly, but it is much less important for rarely used storage. If the storage is used every day Vs 4 times a year the efficiency is 100x more important in the first case.
'Getting most of the job done fast' ist so right. We tend to search endless for the 100% solution instead of doing what is already possible. Thank you very much Rosie.
That's such a great takeaway from the video. It's true, focusing on the practical solutions we have now can make more progress than waiting for a perfect one. Rosie really highlighted how getting that 80-90% of the way there with current tech is a huge win.
Lithium ion battery storage has already proven to be more toxic than nuclear in the many fires that have occurred. Moss Landing is a sad example of a nice place now contaminated with toxic metals. The path to hell is paved with good intentions.
Rosie makes a number of very good points.
I notice she didn't mention nuclear, even once.
1 ~ Australia is very well placed for this. Go to places like N Europe and they have real long duration needs that are challenging to meet. We don't have anything like that problem.
2 ~ A lot of early studies and reports on this subject, sharply over-estimated how much long duration storage would be needed, and those estimates are now trending down.
3 ~ A lot of ‘smart’ ideas for this, have got attention, but they’re wildly impractical. Like building circles of cement blocks with a crane ...
4 ~ The cost of battery tech, Lithium Ion and the soon arriving Sodium Ion, is coming down to the point that many, if not most, of the previous ‘smart’ ideas simply don’t make sense any more.
5 ~ Hydrogen storage ~ meh, I have reservations about simply pumping compressed air into mine-shafts or caves, let alone hydrogen.
I have talked about this, but ~ if you split water and get hydrogen, then combine that with captured carbon, you can remake flammable fuels, like diesel or Jet-A or petrol. Now this is not going to be cheap, but I think there is a market for it. Make Jet-A and use it for the parts of the aviation sector you can’t just replace with electric battery powered flight, which would be anything with a flying time over about an hour at present. That would increase the cost of jet travel, but jet travel never used to be cheap back in the day, and we survived. I would rather have Brisbane to LA flights available at 4x the cost of today, than simply not have them.
~ Now ~ while we’re talking flying
A few of the Data Centre’s they’re building now, in the US, are turning to old jet engines from aviation hooked up to generators, to make up their huge power demands. Good reliable technology. How about we build a few of those and hook them up to the normal electricity grid, just in case? And then we have a place or a few places, where we keep big tanks of jet fuel, and the aviation crew get their supplies from those places and they are situated near electrical sources, like big wind farms and solar farms, where they do the electrolysis and get the hydrogen? You could also rope in desalination while you’re at it. Add a long distance under-sea cable to Asia where we sell several times as much energy as we consume and replace our international trade in coal and gas, with exports of electricity?
We have done well out of exporting wool, and wheat, and coal and dirt. Let’s move on to exporting electrons. And let’s stop selling dirty brown coal to the world and then tut-tutting about how much carbon other countries make from burning it. Let’s just sell them the electricity without the carbon instead. It’s got to be easier than exporting different brands of dirt.
I very much enjoy your deep dives. You almost always convince me, even when I start out with a different opinion. Thank you for making me think more deeply.
Rosie's missed Heat Storage, which while only 30% efficient for electricity production per se is much more suited to 80% of energy actually needed in homes - which is heating and hot water.
Although (in the UK) domestic consumption is only 25% of total UK energy consumption, that still leaves heating and hot water at 20% of the UK's energy demand. Industry primarily uses gas for heating and electric for lighting and cooling.
Your deep dives are always so engaging! It's great when content challenges our perspectives and encourages deeper thinking.
"Who cares about the last 2-15%?" I think when we find our storage running out due to one of those 2% events, and not enough dispatchable generation to meet the entire grid because it was uneconomical to keep around, quite a few people are going to care actually.
One thing that's glossed over here is that even though you might only need gas for less than 10% of total electricity delivered over a year, when you need it it will be supplying around 100% of normal total demand. That means maintaining backup gas generation system capacity almost as large as the system you would need if it supplied 100% of demand all the time. Except for the later system you would need vastly less storage and long distance transmission lines.
That's a really important point about the capacity requirement for backup generation. It highlights how even a small percentage of gas usage still demands a massive standby system. It makes us appreciate why scaling up transmission and diverse storage options is so crucial, as they could help reduce that peak dependency. Finding that balance between reliable backup and building out the renewable infrastructure is the big puzzle we're all trying to solve together.
The major problem with renewable energy and renewable energy storage is the huge area it needs. In 1988 I had a summer job working for a company installing a flue gas desulphurisation system at the UK's largest power station, a 4GW site, but only needing 6 boilers and turbine generator sets of 660MW each. The site wasn't small and had a reasonably sized coal pile, enough to tide it over between coal train deliveries. But it's a fraction of the size required for a 4 GW wind / solar site with energy storage, especially one for the UK with long winter nights and grey days.
Sodium Batteries are also rushing up onto that chart 😜
This was going to be my point too - sodium is REALLY cheap, so is a real game changer in the not-on-a-vehicle energy storage - which would include energy-storage at bus depots and other charge points.
Yes this should be the logical choice. CATL in China are manufacturing them for cars. With ground based storage size weight and efficiency can be less of a drawback than a lithium battery fire...and also3 times cheaper than lithium batteries.
I long to be powered by salt for I'm not salty enough 😂
Not yet though
IMO Sodium will ultimately win, especially for grid storage where energy density doesn't matter as much. And Sodium will walk it in if it's chemistry is fire resistant and cycle life can be made greater that Lithium.
Dear Ms. Barnes and friends: Most of your videos have been either very good, or very, very good,
This one might be the very best! Thanks for explaining it so well, putting it in perspective, and reminding us to adopt the cost effective solutions quickly.
Keeping it real from 17:20 - this makes such good sense and it is exactly the principle that many homeowners are pursuing now with their solar and battery installations that are still grid connected and trying to decarbonise and save money, rather than be completely self reliant - the 2-15%
Energy Vault is vaporware.
What a pleasure. You now speak at a rate that I can understand. Thanks for making the effort to deliver fewer words per minute. English is my first and only language.
Man , Rosie. You are legendary. Thank you for your reports.
Wow, thank you
I have a good analogy for your last point - which is planning for the most extreme elements. Nova Scotia, Canada, having a maritime climate, gets high winds and ice storms which cause power outages. Some extreme examples have lasted days. When I retired back home to Nova Scotia, I decided in my new house I'd have a generator for when we lost power. I didn't go for a whole house system as they were very expensive but still spent close to $4000 for a new panel, external connection and gas/propane generator. I've been back home for six years and have NEVER used it. Power outages have not been that long to warrant taking the generator from the shed to hook it up. The longest has been about 12 hours, most of it when I was in bed asleep. A few related points:
*Like many Nova Scotian homes, I can heat my whole house with wood so you don't worry about the loss of heat or broken water pipes in winter. This would be different in house without supplemental wood heat.
*Some family and friends have generators and they simply run extension cords into their house to run a few things like the fridge, microwave etc that they want. A much more simple and far less expensive option than what I decided on.
*New solid state power storage units for camping/home use are inexpensive and can power some appliances for 8 hours or so. They can be used in your house without the long extension cords. Even better, most can be charged with solar panels.
*In the end, the worst case would be losing food in your fridge, and if summer, in your freezer. That would be a loss but economically no where near as expensive as spending $4000 that I did. And that's just the capital cost there is also the running and maintenance costs as well. In my case, mice damaged wires on my generator, resulting in a $400 repair on a generator that I've never used.
So I use this example as an analogy for the capital and maintenance costs of long term storage in order to be sure we are covered 100%. Unless it is cost effective, being covered 80-90% of the time will work.
I remember learning about Dinorwig, a pumped hydro installation in Wales, UK, when I was a kid. Even as a young lad I thought it was a genius idea.
Water is so much better as a storage medium with gravity as you can have ALL the water at the higher potential instead of most of it at base level.
It is fantastic but at 9GWh, it's being overtaken by the size of some of the latest grid-scale batteries. There's an 8GWh battery planned for Teeside in the UK, and a 10GWh battery planned in Germany.
That's such a cool memory! Dinorwig really is a brilliant piece of engineering. It's awesome how some ideas just stick with us from childhood.
@16:45 here's where you go wrong: 96.3% sounds very good. But it's not. You actually need 120-150% to assure reliability.
This! I so often hear “the sun doesn’t always shine, the wind doesn’t always blow” as a reason not to build them at all. If we end up with a grid that is covering much more of our total energy needs through mass electrification, who really cares if it still has a few percent gas on it! That would be a great so called problem to have.
5:21 Most batteries have an internal self-discharge rate that will deplete the charge over time even when NOT used. Li-Ion is between 1-4%/month depending on the chemistry and state of charge. (This has improved as manufacturing matures)
Self discharge is because of the use of PET tape a German student in Canada have found the reason now they are working on the tape
@CUBETechieall chemical batteries will have a measurable self discharge rate. We've already improved li-ion significantly but it'll always be there. In reference to this video, she's talking about current battery tech, not ghost hardware some time in the future.
One of my hobbies is observing people in this field who know what they're talking about. I am not an energy engineer. Your videos are one of my favorite sources of discussion on the topic because of your expertise in the field and in making great edutainment videos. Thanks for what you do!
Lithium batteries can be anywhere. They can be in the middle of the city that is using them. Cooling fans and physical volume are really the limitations, and that could potentially be masked with large sneaky facades. This is already done in major cities for grid components and subway/metro infrastructure.
Lithium seems to also function equally well at any scale. Many small batteries or a few large batteries have similar total cost and operation, but can be configured to fit more variation in space and meet more varied demand.
The other LDES on the list all seem too dangerous or simply incompatible with urban areas, so their costs go up by being remote. Along with scale being very important. All of the non-lithium designs improve greatly from scale, meaning they need to be huge in order to be cost effective.
Fascinating topic. I was disappointed not to see some actual numbers for efficiency. Sodium batteries were also conspicuously absent.
Sodium is better and cheaper shortish term storage and not suitable for long term storage that Rosie is talking about here.
@glyng228 One of the major points Rosie rightly makes here is that battery tech has advanced rapidly and those advances were not taken into account by many looking for other long-term storage solutions. That's exactly what you're doing with sodium here. 🙂 If one is talking about batteries, sodium has to come up.
@glyng228 Not true. Sodium Ion batteries self-discharge at a max 5% per month.
A sodium‑ion battery left unused for 6 months will typically retain 70–85% of its charge. Which, considering how cheap they're expected to be is easily built into the project.
Sodium behaves very similar to lithium with slightly different efficiency and economics. But the timescales are the same
Sodium batteries don’t exist in any meaningful manner.
My nephew's 9th birthday is next month, and I recently ordered the Hungry Minds book on restoring civilization because he is a boy who's curious about how things work. The book explains how many human inventions work, and it is really wonderful. However, I was not expecting the book to include content inappropriate for a boy his age. Included with the book was a sealed envelope with a story on the cover. That story talks about how, when they decided to write the book and were deciding what human inventions they were going to cover, "We knew we had to feature sex toys." Believe it or not, some people who had bought the book for children objected when they found the 2 pages about those toys. So in later editions of the book, they removed those 2 pages and included them in that sealed envelope. I showed the envelope to my sister, and her first reaction was that they must be joking. I opened the envelope and saw they were serious. I still plan to give the book to my nephew, without that envelope, of course. I am going to trust that the rest of the book is appropriate. However, I am still shaking my head at the idea that they thought "they had to cover sex toys" in the first place. Are they really necessary to rebuild civilization?
New Zealand calling, we’ve been at 80% renewables for decades, with thermal making up the final 20%, and it’s that final 20% that sets the price of electricity, the tail wagging the dog.
Sure but hydro is a synchronous generation with big ass turbines driving alternators.
It's not inverter based resources.
Only 80% ? (laughs in norwegian 😛 )
we have been just about 100% hydro electricity since 1880's 😁
Too much rain and mountains really helps tho 😅😊
Right on
Yeah most countries have a bigger population and don't have thermal
@zigge1989you were heating with electricity and driving electric cars in the 1950?
I really wish this vid was extremely widely watched in Australia. We have it so easy with renewables if we were only more common sense about it.
Another solution to the dunkelflauter is not storage but very long DC high voltage transmission lines. Move the power from where it is available to where it's needed. I don't know how big a part of the solution this will be, but probably will be significant in some geographic areas.
The proposal for HVDV is a simplistic statement. We need a strong transmission network to support the distribution networks. HVDC is but a part of this network. The inhibitor in most places, outside China, is: “not in my back yard” supported by legal inhibitors - which in principale protects Homes and individuals but in practice inhibits new power distribution possibilities.
@JanHeisterberg-Andersen HVDC directly addresses many of the objections people have for long distance transmission.
weather is still correlated in different locations, so HVDC can't really shift peak power generation from wind or solar by more than an hour or two unless you make transmission lines that are 1000s of miles long, and there's always the chance that temporary reductions in power line up at both ends. HVDC is important for connecting things like offshore wind or other cheap generation that's far from major power consumers, but I don't think most reasonable HVDC lines can replace energy storage, especially since storage keeps getting cheaper and is generally easier to build.
@thamiordragonheart8682 there are plans mooted for sub-Saharan African countries to supply solar generated energy to Europe.
@thamiordragonheart8682yes, especially in Australia weather is correlated.
I mean if we were in some sort of post apocalypse with limited knowledge and tech this would be pretty useful. A bunch of slaves/animals could move the blocks up the tower.
A cart full of rocks up mountian side with gondola setup would be simpler.
My favorite "free energy" system is when they experimmented with pumping deep water up to use for various cooling schemes. (Atlantic ocean).
You're absolutely right. In the latest subsidy scheme for home batteries in Australia, the demand exceeded the prediction by a factor of five. 90% of the challenge is solving itself. Countries with nuclear capability can easily cover the final 15% with that. Others can burn gas until we come up with something better.
Transport is the real challenge where we need innovation. Shipping and aviation are the hard ones.
Nuclear is the most expensive thing to use for dispatchable generation that you only need intermittently. The cost to build them is huge but the running costs are much less. Thish means that you want to run any reactors you have as close to 100% of the time as you can, otherwise you have to spread the cost of construction over few kWhs that are generated.
CATL has stated that fully electric, ocean-going ships could be commercially viable within three years, so even that is on track to be solved.
That's a really insightful point about the home battery demand outpacing expectations so dramatically. It's encouraging to see that kind of uptake. Your breakdown makes sense, and focusing innovation on shipping and aviation is a smart call. Those sectors are tough, but seeing progress elsewhere gives us a lot of momentum to tackle them.
I think this is the best nuanced video on this topic I've seen for long. It's basically the china strategy. And I've been saying this for years! Thanks
I would argue that Seasonal Plus Energy Storage (SPES) isn't only about displacing the last 5 to 15% of fossil generation to cover dunkelflaute, it can bring other benefits to the electricity system.
Unless a country is in the fortunate position that they have large hydro resources, such as Norway and New Zealand have, then I would suggest that the issue is probably not just 'how do we decarbonise the last 5 to 15% of generation'. If the renewables are predominantly wind and solar then, once you get to substantially more than 50% penetration, another important issue, especially in countries where solar is highly seasonal, then without seasonal plus energy storage (SPES), curtailment is likely to increase substantially, which effectively increases the cost of renewables. To paraphrase Henry Ford, 'If you have renewable energy and you don't use it you will ultimately find that you have paid for it but don't have it.'
This means that you need some sort of chemical energy storage technology, like, but probably not, hydrogen.
That's a really insightful point about SPES offering benefits beyond just covering those final gaps in generation. The connection between high renewable penetration, seasonal patterns, and curtailment is super important and often gets overlooked. It makes total sense that effective storage could help optimize the whole system and make renewables more cost-effective in the long run. The Henry Ford paraphrase really drives it home! The discussion about what form that storage takes is definitely the next big puzzle to solve.
Use nuclear as a strong consistent base to mitigate that problem
Hi Rosie, another form of long duration energy storage is hot sand batteries.
pumped hydro is just another form of gravity storage.
Yes, Rosie explained that. . . . AND - what's your point?
True, but it is one of the most cost effective versions, which is why it is so wildly popular with utilities.
@jimthain8777Most popular ? Was most popular. utilities are not still building a lot of it. There’s Snowy 2 planned for 40 years. But what else?
The reason utilities don't build more pumped hydro is because it's easier to just buy batteries.
The reason they should build pumped hydro instead, is because pumped hydro has a lifespan of 80-100 years with extremely low operating and maintenance cost.
Battery/inverter systems need to be replaced every 4-15 years when used daily, creating a lot of toxic E-waste, a high demand for critical minerals, and creating billions of new batteries each year just to maintain current capacity. Batteries are a consumable and are expensive. Dams and turbines are not.
@jasonneugebauer5310no utility battery system comes close to doing what a large PHS system does, 10-12 hours full power, 3 GW, 90% round trip efficient, 80-100 year lifespan. But PHS has specific, rare requirements: preexisting water supply, dual reservoir geology, separated by just enough elevation, and the PHS economics require a charging source available every day of the year, for low marginal cost, at night, which usually means a nuclear plant.
These conditions suggest, that the principal goal should first be to build a fleet of nuclear, and then get some matching PHS as a bonus.
A use for the world's ski lifts after the last snow falls on the earth!
@17:35 Spot on. We need to rapidly decrease emissions now and start with the low hanging fruit.
I feel like the last 15% could pretty easily be nuclear power.
Especially for seasonal storage, the number of charging cycles is limited to the lifespan of the installation, which makes cost/kWh relatively high. Any storage solution will technically work, but its cost must be compared to installing more renewable sources to cover winter shortages. Even if that extra renewable capacity is switched off during the summer, it may still be a cheaper solution than seasonal storage solutions.
A true engineering plan instead of a fake goal. great video
Agreed. No point being a slave to perfection now when there are so many other areas to decarbonise. However, it does make a "net zero by 20XX" narrative more complex if we say "let worry about that later"
"Net zero", not zero emissions.
May be we can build solar farms in the desert regions near tropics like Mexico and Yemen to capture those 2% of CO2 emitted in polar regions.
Also people forget nuclear and geothermal. Many cities can easily use a few reactors to power them. Take Australia if you build nuclear powerplants for relatively colder cities like Sydney, Melbourne and Perth you can build solar in solar and iron rich northern region to produce green steel.
That's a really thoughtful point. It's true that balancing immediate action with long-term goals adds complexity, but it also shows how dynamic and multifaceted the decarbonization journey is. Every step we take now builds momentum for tackling those tougher challenges later.
The one benefit of gravity storage is it outputs the same power all through it's discharge cycle. Thermal storage, flywheel etc. starts out with high power and it gets less the nearer it gets to empty.
@EngineeringwithRosie - 2025-12-24
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@erkinalp - 2025-12-24
instead of having a 6 month battery, why not send the energy to the other hemisphere?
@rollling7523 - 2025-12-24
LDES is amazing
@brianwnc8168 - 2025-12-24
Did you talk about thermal storage? This is an emerging market with lots of approaches being explored. Large scale examples already exist in the energy marketplace.
@sermadreda399 - 2025-12-24
I will be in China soon ,you have no idea how BIG is this subject ,if u want we can cooperate I already have 2 provisional s and another 4 in the line , revenue and clients are in Que
@komisiantikorupsikoruptord6257 - 2025-12-24
China is building 2 gravity energy storage to help their construction sector which is currently kaput after The bursting of the housing bubble.