Using super low cost readily available, environmentally friendly materials, e.g. rocks for thermal energy storage is brilliant! Shuffling air back and forth between hot and cold storage tanks is a bit like a slow cycle Stirling engine with lots of thermal mass in the regenerator.
And you think nobody fought of that before? Really? You’d better look for answers why it has not been put to use. It ain’t cheap, it ain’t super efficient, and it ain’t that environmentally friendly. Start with the overall efficiency.
@@JDrwal2 Efficiency is NOT IMPORTANT here, these systems use energy from wind farms and solar that are being switched off because there is no where for the electricity to go. It’s more important to have a large volume of storage with a lower capital cost than Li Ion batteries than it is to be efficient. 60%:is approximately the same efficiency that is targeted for liquid air storage.
@@JDrwal2 Efficiency was important when you had to pay for every unit of energy consumed, back when big oil and big coal made the rules. In the renewable world, what counts is the cost per unit of power, not energy. Example: photovoltaics trumps gas generation despite one third efficiency.
Great video Dave. I work in energy consulting, and I use your channel as a launch point when I am researching emerging energy technology. It is difficult to keep up with the pace of development in energy, but your channel fills that breach. Kudos.
I wish my PM (Scott Morrison) would watch your videos. Recently he ridiculed renewables in defense of a proposed gas fired plant, "the sun is not always shining, the wind is not always blowing". There are SO many alternatives to fossil fuels we just need to choose which will be the most effective.
we dont even need to choose, we should support them all in parallel from yesterday onwards.... some will win, some lose, some will be very situational but we shouldn't fall into the incrementalist fence sitting that ScoMo is so expertly fond of
It is so wrong that we (Australian ) have such an idiot leading the decision process when most the science is clear that we need to change our energy policies fast !
What sparked my interest immediately was how an aluminium or steel smelter could use their wasted energy in this tech. Also geothermal. Very good. A cost comparison between compressed air would be interesting.
Edit: I misunderstood, sorry. No, the waste heat is only 75 degrees. Even it was 400 degrees or so, it is not usable for smelters. However 75 degrees is great for heating existing homes and offices.
@@roland9367 he said "how the smelter can use it's waste heat" so you have misunderstood him. He thinks the waste heat can be used as a booster , so the solar won't need to heat the rocks as much.
I think the future is going to be different generation systems that are site specific to what's needed, what can be used, and cost effectiveness coupled with a range of storage sites and redundancies that can communicate
Always happy to see Yet Another Storage Technology come online, particularly one that doesn't contribute to the overall environmental contamination problem.
Dave, ur a star!! i find ur show in the top 10 of the entire iNet. the info you provide is top knotch, and ur delivery second to none. keep up the good werk.
The clarification about long-duration for li-ion batteries was very helpful! Likewise, acknowledging the steep competition in the industry is appreciated, and some discussion of head-to-head comparisons would be really interesting as well.
This is exactly how I imagine large batteries. Pumps going back and forth. Was not expecting purely thermal storage, though - this could be built anywhere!
Check out on the economies of solar thermal molten salt storage. Under the hood the maintenance cost is the killer. The same here. Admittedly excellent thermodynamics on paper. Material science screams no no no.
@@cyklonetidalenergy7141 I assume the maintenance cost is high because of the molten salt being present in the pipes. If this system uses air, it doesn't seem like maintenance is any more burdened than that of empty pipes and containers? Though, admittedly, these pipes and containers do need incredible insulation. Would like to hear more specifics (and links are totally fine) on what you are worried about.
@@cyklonetidalenergy7141 On the contrary . . . Almost all the components here are mature common parts. Pumps, heat exchangers, turbos, compressors. All already optimised and cheap.
@@andy_rb a water pump is a mature common part. A pump for 650° C hot corrosive fluids is not. That is the key point here I was trying to get across to people. Especially if you connect it to a storage going from deep frozen easy to crack metal and cycle and expand it including all required insulation up to 650° C in very short time. This thing is useless when it takes 12 or 24 hours to reverse the ops mode of the process. The rapid changes put a massive stress on materials in aggregates, pipes and containers. It can work for sure. Is it economical? maybe on the side of rather unlikely. Let's hope the best for them ... good luck. Enjoy the journey. Either they done calculations well or they did not care for sake of the highly desireable project goal impact. It impossible to understand what the true challenges are without testing and taking it step by step. The container casings and designs do require technical and material science niche expertise way beyond my scope. On pumps I have a lot better understanding and I know for sure they are far away from any commonly available parts you can just by off the shelf. There is very few stuff you pump that hot at all. Then it comes down to sizes, cost and maintenance. Just compare to OTEC which is stuck for 3 decades now. Much simpler yet no progress on similar ends and means. Still just pumps and other off the shelf stuff at just normal temps.
@@buttonasas Air convection is a huge efficiency sucker and not what they speak about. You need a liquid other than water for this process for efficient heat transfer. Steam or ice both cause issues here. Eventually some kind of oil or molten salt will be used as a heat transfer medium. Not that environs friedly I guess.
@@JustHaveaThink Oh, thank you! I saw it. I meant to comment that while you were speaking I was recalling Rosie's video that I had seen a couple days before... until you mentioned it. It was no coincidence!
Do we have any indication of the metrics..? Capacity MWh/ ton or MWh/ cu’mtr ? Charge/discharge power rate MW/ ton or cu’mtr ? Capital cost estimates per GWh ? Typical energy storage cost per MWh ? Etc
So many heat-based storage systems coming up. I would never have thought that, of all things, heat would be such an attractive choice for energy storage (mostly because it seems the hardest to extract energy from).
ref 0:15 The predominant storage at the moment is water (pumped hydro). In batteries Li is off-course the dominant technology, but that is so fare just a small fraction off total storage capacity.
@@hernanposnansky4830 That odd since the older installation in Norway have a round trip efficiency of 84-87%. Newer installation 90-92% and added costs not that much since the generators are also the pumps. No added infrastructure needed. NB: All installation in Norway is part of hydro electric power plant with dams.
bknesheim I do not disagree with you. I was refering to the average round trip afficiency at the point of insertion to the grid. These are the particulars of the one of the older started in the early 1900's The turbines are Pelton wheels, where obvoiusly separate multistage pumps and motors are required and in some cases very long distance from the dam to the actual turbine, which involves reversing the water flow. The older pipes had a smaller diameter, which create a larger pressure loss. Remember that the flowrate for a given pressure (water level difference times dens. times g ) is proportional to the fifth power of the diameter in turbulent flow. Also the ' inertia ' effect due to reversal of the flow direction is inversely proportional to the flow area, in other words it takes some time to revert from production to storage, where the water flow is decreasing and is wasted because a pelton turbine operates at one exact speed ( one half the jet speed at the bucket radius) and the generator does not operate at partload efficiently. These are not the only factors which determine the average roundtrip efficiency, Certainly newer installations and improvements are better. The other factor is the market, where short term power arrangements are made sometimes within hours. If you cannot supply , invariably you must avoid to waste stored water. The operating company gets paid for delivered energy at the price negotiated in a short term, so economical decisions affect the operations greatly and that is reflected in what I called average efficiency.
Really cool how the stratified regions of each tank act as a kind of counter-flow heat exchanger. If your reference frame follows the transition region, you can think of the air flowing one way while the rock flows the other.
It is actually the exact opposite of the usual counterflow heat exchanger (or a countercurrent solvent system). Those are designed to keep the change in temperature (concentration) as small as possible at each point. In contrast this system tries to maximise the change in temperature at each transition. They hope thereby to improve the over all efficiency. I don't myself know enough thermodynamics to grasp why in some processes (like this) it is efficient to have big temperature changes and in others (where counterflow is favoured) it is better to keep them small.
@@trueriver1950 No. It is a counterflow heat exchanger. The key characteristic is that the media flow in opposite directions, with one end hot and the other cold. The media thus swap temperatures. The difference in temperature between the media at any particular point is small, but the overall temperature difference between one end and the other can be as large as you like. In this case the rock doesn't actually move, but that's just a matter of reference frame. There is a narrow band over which the temperature change occurs. Follow this up or down during charge or discharge, and the rock can be considered to be flowing in the opposite direction to the air.
It is certainly an concept that needs to be explored and on paper it seems like a good idea but with my experience with any heat recovery system is the initial build cost on going maintenance cost and it's longevity against all its returns which don't always reach the projected forecasts. Keep up the good video commentaries and stay safe.
Been very focused on clean energy since the late 60’s - having a front row seat of this massive impending disruption is awesome! Particularly as a mechanical engineer. The rate of innovation is incredible!
Innovation.? Or rather designs having their 15 mins. It's not the innovation, it's their adoption. The spotlight, how ever powdered, has been turned on.
@@robertwoodliff2536 Oh I think there has been some pretty serious innovation happening Robert - I'm a mechanical engineer, I did my thesis on windpower in 1981 - the innovation in the energy space has been brilliant!
@@garry8390 Seemingly not. Innovation & adoption in renewables is far out pacing that in nuclear. I guess nuclear’s future is looking uncertain at best?
@@nicennice what seems and what is are two very different things. Renewables are bullsh*t used by crooks to suck up public money but by the time you wake up and realise it will be too late.
Great video, it was really cool to see a follow up of the progress Bo and the Gridscale team have made since I visited them nearly a year ago. So cool to see they've got a pilot project coming, I thought at the time that they were well set up to move fast and it seems they have done just that. Also... I am in awe of your animation skills - are you still doing these yourself?!
@@Skoda130 UA-cam videos can be viewed with secret links before they are scheduled to be published. It's honestly beyond me how so many people still don't know this is a thing.
There was an English startup 10-15 years ago based on the same approach, but seems they faded into oblivion. I'm glad to see another startup making good progress. When I did calculations on the prior startup it seemed quite reasonable with a pair of building sized storage units (for hot and cold) not taking much area, and claimed round trip efficiency quite high. The Stiesdal claim of 55-60% seems competitive with iron-air and other technologies emerging for longer term storage. Insulated rocks are pretty cheap-- the 10EUR/kWh is pretty amazing. I wonder what the cost/W for the turbine-motor-generators is. This seems much more practical than liquefied air or CAES. Gravity batteries are not even close in cost and size, except maybe the electric train up a mountain.
That’s very interesting how the lion storage should work in tandem with these heavier grid scale applications. That immediate management of frequency was highlighted in a talk about why hornsdale was so successful. An idea for a video may be to build a table with all these solutions listed along with properly levelized cost per kWh? Very exciting stuff!
LCoE for storage doesn't really tell the story. Hornsdale paid of it's CAPEX within a two years, ROI that is unheard of in the energy markets, primarily because they were the first on the NEM with this technology and stitched up a sweet deal with the SA Government for ESS in addition to playing the FCAS markets.
@@alastairleith8612 yes Toni seba was pointing out the lcoe is all wrong so I am speaking loosely here hoping to see leveled cost properly calculated and compared for the different propositions, many thanks
The Ambri liquid-metal battery seams to be a mechanically simpler system that would require far less maintenance and greater safety. But the key maybe to have multiple options in long-term storage that may be preferable in a variety of locations. I can see the Ambri liquid-metal batteries being ideal in remote locations powering small communities, such as the Canadian Arctic, replacing or augmenting diesel generators.
I'd agree the Ambri battery is exponentially an easier system to use but I'm thinking it's going to degrade its ratings if you begin using the heat that it requires to work, for other purposes. It may have some heat that can be taken but I'm guessing it's not going to heat an artic town
I reckon this will give about 20 Wh/kilogram, vs 100 to 265 for Li-ion (have they made claims about this?). To compare with gravity storage, it's fun to divide these by gravity to convert them to heights. 20Wh/kilogram is about 7km. 265 Wh/kilogram is 97 km (i.e. a lithium battery powered elevator could get most of the way to space)
@@Aaron628318 Wh/m2 could be more of a concern in areas with limited land availability. But since solar and wind also need large areas of land compared to a traditional or nuclear power station if you can site them together this may not be a problem. It's good from a grid point of view to have them together because it takes away some of the variability of current leaving the site. Can't do that with offshore wind though!
There are a lot of hot rock proposals around, but in my view there needs to be a phase change to make it efficient. You also need to consider whether you would be better off storing excess energy chemically, eg. as hydrogen or ammonia.
I've been watching your videos for quite a while now and didn't realize I hadn't subscribed. I get all your notifications anyway, UA-cam knows. I HATE it when people beg for subs or ask you to subscribe because most people just do it in a very offputting way. You're definitely not one of those people and I am now subscribed. :) 500k subs should be just around the corner
In the coming years and decades filling stations are going to have a lot of large tanks under ground made redundant by electrification. Given that nearly all these stations will have at least two of these tanks for petrol and diesel, could these be converted for use in this sort of system?
Thanks for the most pleasing discussions without political rhetoric, yet with the facts about reducing our impact. We humans have always improved - it’s what we do - by considering better ways, always. It’s done by sentient, caring discourse like this.
I'm always amused when PV solar is used to electrically heat a medium in order to store energy. I'm not saying it's a bad idea and it allows it to work in concert with wind. However, it seems like if the solar is solely charging this system, wouldn't it be immensely more efficient to use solar thermal to heat the medium, or maybe a combination of the two so as to maintain the wind inclusion. Just a thought.
This is _not_ electrical (ohmic) heating. It's effectively a heat pump/heat engine to create a temperature difference as storage (note that the cooler of the two tanks is _colder_ when the system is charged). If the ideal case is considered, there are no losses.
For efficient energy out of thermal you need a high temperature gradient. You need 600 or even better 1000 degrees of Celsius to drive turbines and store energy. There are some new projects for solar concentration towers. They are more expensive than pv but are practically production and storage in one. The heated up molten salt can drive air turbines with a heatexchanger, but also store the heat, to let the turbines run in the evening and over night.
I guess the idea is not that there are dedicated PV modules installed only to provide heat. Instead, if you have a grid with a lot of wind and solar then you will have times of excess production (e g. at noon) during which this kind of system will be charged.
In northern countries like Denmark- there is not much sun in winter. But there is a lot of wind energy generation (often more than needed), and there is a need to store that energy, as generation is uneven. I'm certainly interested for this in Lithuania, as some grid balancing solutions are needed if we want to expand our wind energy generation, to proceed with the plans with building offshore wind farms this decade.
Until people actually started to see the consequences of climate change no one had the impetuous to do anything. Humans never take action until issues become a crisis.
It probably did, the level of oversite of what public officials could sweep things under the rug, so to speak, is mind boggling! The state has always maintained that state secrets protecting us and our freedoms seems to be getting thin for us but it sure protects them from either incompetents or pure coruption, considering that the “terrorists” always succeed in taking away our freedoms in how we have to give them up to the state so the state can protect us from who the state went out of their way to create in the first place!
I agree that these developments are coming very late in the game. Also, they need to be accompanied by a radically scaled back expectation for never-ending growth on a finite planet (one of the fatal flaws in capitalism that have already driven us to ecological overshoot).
They basically use off the shelf components that are used in the industry for decades. The systems weren't interesting before, because the renewable production capabilities weren't there. Storage is only needed when we shut of fossil fuel power plants.
Another optimistic video. Ahhh... we need it. I'm getting to the point where the doom is sending me over the edge. Cheers Dave for all the reasearch and clear presentations.
Way back in the 1990's several advocates of compressed air storage technology were talking about similar systems but they were shouted down by the electricity only solar and wind people. The idea of putting a compressor not a dynamo in the windmill meant you could store the air. Running chilled compressed air though pipe at the focus of a solar concentrator would produce more stored energy. The world decided to go down the path of electricity only and so these kinds of pneumatic and thermal solutions have been ignored for 30 years.
Thank you Just Have A Think for all the very interesting & useful info. You may have already talked about this but I wondered what thinking there is about flywheel energy storage as I here very little if anything about it on the media.
Would be great to see a comparison of Lithium Ion verses Lithium Phosphate batteries for EVs and quick energy draw. Also a comparison of Zinc-Air Flow, Iron Flow, Zinc Bromine Flow, etc battery systems for long-term storage.
I have a long duration energy storage medium: uranium, plutonium, and thorium. They store the energy of a supernova that happened 5 billion years ago. 🤗 We need load-following liquid metal cooled fast breeder nuclear reactors to balance out renewables.
This seems like a promising concept. Though whatever happened to the compressed air energy storage system? Also a modular and scalable grid sized energy storage solution.
mi point,compres air more better 60% without complicated sistem, ofcurs if reheat is done with ambient air the% is better ,and if windmills compres the air directly % increase,no storege loses,but no patent ....
Isn't Highview Power basically using the compressed air idea (but storing it as a liquid)? Not sure what they claim as their operating efficiency, but maybe around 60% too?
@@yvanpimentel9950 Critical is the energy density which is low for compressed air. As a result, the cost of storage, in my opinion, will be significantly higher for a warehouse that is to have an energy reserve of several days.
@@lawrence18ukThis company cheats a bit because the efficiency is similar when you have waste heat at your disposal. "In isolation the process is only 25% efficient, but this is increased to around 50% when used with a low-grade cold store, such as a large gravel bed, to capture the cold generated by evaporating the cryogen. The cold is re-used during the next refrigeration cycle.[3] Efficiency is further increased when used in conjunction with a power plant or other source of low-grade heat that would otherwise be lost to the atmosphere. Highview Power claims an AC to AC round-trip efficiency of 70%, by using an otherwise waste heat source at 115 °C" . All these systems are so-called Carnot batteries. I believe that this is the best solution to the question of which one will win.
The compressed air system is being built near Manchester, UK. Hopefully we’ll see some results soon. Hopefully there will be room for many many of these different technologies going forward.
Brilliant Idea, these are the kind of news that makes my week. Thanks so much for the program for the research and for explaining so clearly and simple that anyone can understand. Once again, thanks so much for the great effort in this program.
Have just discovered the notion of using ammonia as a fuel - especially in the shipping industry. A friend who is working on a pivot to carbon free everything mentioned it and I had never even heard of it! Would love an article on shipping and/or just ammonia as a fuel if it appeals. :)
One thing is you need to get z handle on is the nitrous oxide component as the waste gasses of the combustion process. Unless you can run the exhaust through a catalytic converter maybe.
Ammonia as a fuel is a bad idea - it's well regulated at the moment because of its potential to be used in explosives. Making it a fuel source would make regulation a much trickier problem.
Super Video. Strange that I have to find out, about this on you tube, and not on Danish T.V. I will go down, and check out the operation. What an exciting project. Thanks for the video. 😘🙋🏻♂️
Whenever a new technology is presented, it is tempting to jump to a conclusion. JHAT resists that temptation and presents the facts objectively. In contrast, many posts on social media are hasty reactions which attempt to champion one technology over others, based one particular characteristic. This should not be a binary debate. Dave's introduction explained that an energy storage technology might be optimised for one or two desirable characteristics, but cannot deliver them all.Therefore we should expect energy grids to utilise several technologies to generate, store and deliver power. We should be aware by now that there is no 'one size fits all' solution to sustainable energy. So let's keep an open mind to the possibilities offered by all innovations. Technologies that may appear unpromising when viewed individually, might prove very effective when combined.
Well put. The current multitude of potential solutions will be whittled down to a relative few that utility companies can choose from based on cost, local natural resources, performance requirements etc.
I agree with your sentiment, but the fiasco of Theranos shows the danger falling for "game-changing"/"revolutionary" "hypes" that do not, in fact, stand up to honest, unbiased scrutiny. Capital investment is a finite resource - we can't afford to throw money at people and designs that never leave PowerPoint slides into practical prototypes. Case in point: the "bladeless turbines" that this channel promoted which have no chance of delivering what its creators claim in real life conditions - the numbers simply do not add up.
I love your Channel but... In the analysis below, I am assuming that the second law of thermodynamics does not exist, so that there are no energy losses. The specific heat of basalt is 840 Joules/Kilogram/degree C. The specific heat of granite is about 800 Joules/Kilogram/degree C. So a differential temperature of 630 degrees C means that 1 kilogram of basalt can store 840 * 630 Joules = 529,000 Joules of energy. One Watt is a Joule/second, so 529,000 Joules can deliver 529 KW for one second. But one day is 86,400 seconds long! So 1 Kg of basalt can only deliver 0.0061227 KiloWatts for an entire day. Since the average American household uses about 30 KiloWatts each day it means that you would need about 4900 Kilograms of basalt to run just one house for a day. If you include the second law of thermodynamics, you probably need to multiply that number by 3. We have run out of time. Yes, we can use wind and solar during the day and on windy days, but for long-term base energy, we need molten salt nuclear reactors. We can only get about 2 eV of energy per atom out of the chemical energy found in batteries and even less from thermal atoms bouncing around. But when you fission a single uranium atom, you get 200 million eV of energy or 100 million times as much energy! We have enough thorium and uranium to run the world for hundreds of thousands of years. With molten salt nuclear reactors, we just filter out a few kilograms of fission products each year and store them for 300 years in my backyard after I make a few trips to my local Home Depot. We can either use those atoms today as a preventative measure or in 100 years as a desperate measure to try to stop the Earth from becoming another Venus. We have already lit the fuse. There are huge amounts of carbon up in the Arctic in the permafrost that we have been stockpiling for the past 2.5 million years during the Ice Ages of the Pleistocene. Once that bonfire starts up, we will have lost all control. These are not normal times. We are all living in a historical crossroads of humanity. Are we going to make it or not? Unfortunately, I believe that this is why we see no evidence of Intelligence in our Milky Way galaxy. All carbon-based forms of Intelligences always kill themselves off before a machine-based form of Intelligence can arise. Because the Darwinian processes of inheritance, innovation and natural selection require many billions of years of theft and murder to bring forth a carbon-based form of Intelligence, it seems that all carbon-based forms of Intelligence have a real problem with turning off the theft and murder in time to save themselves. Regards, Steve Johnston
I agree about our proximity to Arctic Tipping Point (and oceans and Amazon) and need for acceleration of new nuclear. Unfortunately the window is narrowing I believe and we have spent and delayed the social capital in other ways.
Check those numbers again. It certainly takes a lot of KG of basalt at 630 deg Celsius differential to power a 30kwh a day use-home. But it’s about 203 KG at 100% efficiency or 340 KG at their 60% efficiency goal (assuming the waste heat is not used elsewhere). 340 KG per house is still a lot but way better than 4900 :) I agree the situation is dire and alternatives like fission need to be embraced. Also radiating waste heat at 8-3 micron into space instead of just shuffling it around (like home Air conditioning) is another thing individuals and business can be doing soon.
Interesting. I would like to see some numbers. For a given kWh amount of storage, how big would the cylinders be, and what range of kW power output would be expected?
I've just done some back of the envelope calculations. Assumptions: provide 1 GW for 1 week, basalt specific heat capacity 2 kJ/kg·℃, same for the cold reservoir (which need not be basalt), 50% fill (need air gaps in the rock for the hot/cold air to travel through), 600℃ hot and 385 ℃ cold as given, generation efficiency 20% (from the website). (Note, the temperatures at the input and output of the generator are the relevant ones, not the -30℃.) The calculations work out to just over 10_000 cubic metres, about 10 Olympic swimming pools' volume. (Using a cubic meter to swimming pool calculator I found on the web.) That's inside the insulator, so add maybe 20% - 30% to that for total volume. And then another 50%, say, for contingencies. 1 GW is roughly a "typical" thermal baseload power station these days, although newer ones tend to be bigger. The internet seems to think it's enough for 300_000 homes, so taking non-residential use into account, enough for a small city of 150_000 to 350_000 people (maybe). It's a lot smaller than I thought it would be, so I've probably missed a power of 10 (or two) somewhere. Edit: on rechecking the specific heat capacity of basalt is more like 0.8 rather than 2, so multiply the result by 2.5. 25 swimming pools.
@@gregvanpaassen My b-o-e calcs suggest that about 1E6 m3 would be needed to store these E15 J. About 100x more than yours. One or both of us is astray! Which for me reinforces that for this video to be useful it really needs to provide an example with numbers. A good device that is impossibly large is not very useful. But then your example suggests storing the output of a nuclear power station for a week. That is huge. The same amount of energy stored in diesel fuel would require about E4 m3? A lot smaller, if still huge! I think the essential issue here is that existing liquid fuels have high energy densities that are very difficult to achieve my other means. We find this hard to believe.
@@gregvanpaassen Good calculating but one week is too short, more like a month, at least. UK wind farms have been running at less than 25% usual supply for last month or more.
@@jimgraham6722 Sure! I just used a week for the purposes of getting a sense of the size needed. I agree that it's too short for reliable supply from wind, without huge investments in long distance, international transmission lines.
Thank you for another wonderful video. And thank you for explaining the process in detail like that. You always do such a wonderful job of avoiding jargon and getting to the heart of how things work. It's interesting that this concept doesn't rely on some new breakthrough or previously ignored technology to work. It's put together from common components and the innovation is in the process itself: all the heatings and coolings and the various machines that are plugged in between the tanks. It may be rated for 10 000 cycles, but if the only real points of failure are the compressors and expanders and generators, you could just swap them out for new ones when they age and keep going on and on. The rock inside the tanks may erode into smaller pieces eventually from all the thermal expansion and contraction, but that wouldn't change it's heat capacity.
The problem with any grid scale long duration energy storage scheme is that you get diminishing returns from low utilization of long duration capacity and you still run out of capacity for longer durations.
Really interesting - thermal storage like this was being developed in the UK years ago, but it’s good to see the Danish are bringing something to market.
@@mju135 i get that… what if the air it takes in is pre-heated? Wouldn’t that make it more efficient? I guess sensibly using that heat directly would probably make more sense, but still… if no other use for the heat can be found maybe this could be useful?… 🤷♂️
called junk heat because it lacks intensity to be of much use. Usually preheating but if the temperature differences are low, just the energy in moving the air around might eliminate any benefit.
CAES (Compressed Air Energy Storage) is far simpler. I can only see this suppasing CAES if energy efficiency is far superior. That said using the waste heat for local area heating systems may be the best replacement for gas heating over the next 20 years.
60% is pretty good for long term storage. I've not seen any efficiency claims from the compressed air marketers so I suspect it is are quite a bit lower. Do you happen to know?
@@w0ttheh3ll another problem with compressed air storage is actually having a place to store the air. what I've seen usually involves underground storage which could be limited by location.
An advantage of this over compressed air is that the pressures are much lower. P1V1/T1=P2V2/T2 gives a pressure rise for the main energy input circuit between 1 bar at the inlet temp of 385C(658K) and 1.3 bar at the outlet 600C(873K). So say design the tanks for 2 bar, which will be trivial. Compressed air needs several orders of magnitude higher pressures to be useful, with associated structural challenges.
Not really, it kind of the same thing as you have to heat the air as the pressure drops or it will cool and you lose all the efficiency. This is essentially that, but with heat recovery.
At 0:12 the predominant grid scale energy storage medium is large storage dams that provide seasonal water storage for drinking water and irrigation which also have Hydro Electric Power stations. These are supplemented by Hydro Electric pump storage which provide additional output. In the UK hydro power resource is limited and some of the resource remains undeveloped due to resistance from people who want to keep wild places natural.
New York state and the UK are building compressed air storage. It's the same concept and scalability without the rocks. Plus it's all off the shelf parts, just steel no rare elements. No reason to have huge stationary lithium batteries all over the place. Some of the place sure
No sense in lying,I cannot honestly claim to understand this system. Apparently the inventor knows what he is doing,so I must do more research. Thanks for an interesting and educational video!
If you are in any way MINT-inclined, I would suggest you watch an online lecture on thermodynamics and check out how thermodynamic cycle processes work :)
I like the concept, but since windmills tend to become larger and higher, I wonder if it would not be viable to have a weight towed up using the excess energy when demand is low and wind is blowing and then lower the weight when there isn’t enough wind but energy demand is high.
Try to imagine the engineering challenge involved in that; it just isn't economical in my opinion (but I'm not an engineer). Do your own calculation for Gravitational Potential Energy (it's a pretty basic calculation); you'll see there is very little energy stored by raising mass. For example, a 1 metric tonne mass raised to 100m contains roughly the same energy as just 3 or 4 laptop batteries.
@@gregx1044 you’re absolutely right Greg. One ton raised 100 m only has a potential energy of a measly 0.27 kWh. I should’ve done this back-of-the-envelope calculation first.
Its a brilliant and very promising idea. May not succeed at first, but the basic concept is very solid. Flexibility, availability and cost are all very favorable. Crossing my fingers here.
I'm looking forward to Liquid Fluoride Thorium Reactors (LFTR): ... Screw this noise about wind and solar, or compressed air. In Europe there's a lack of wind and now they need to lite up the gas fired plants. And what if we have a large scale volcano event.... bye bye solar. Batteries are needed to mitigate variances in power and load in the grid. The Stiesdal system looks like a maintenance nightmare. There are only two current large scale compressed air systems operating. One in Germany the other in Alabama. Both are over 20 years old.
I don't see the maintenance issues, pumps, turbines, and pipes are all well developed technologies. We run turbines in hydroelectric dams or natural gas plants for decades, they have been very stable and reliable. Admittedly components operating at 600°c may wear out more quickly.
Maintenance nightmare? In addition to what Doc Watson says, LFTRs also run at about 650 ℃. Instead of air compressors and expanders they need fancy water purification systems for the steam, and steam turbines which run at pretty much the same temperatures as this system. And then there are the systems for pumping around the hot, corrosive, radioactive molten salts, and filtering and purifying them. Those latter systems are the maintenance nightmare. This system uses temperatures, machines and materials with which we have many decades of experience.
@@gregvanpaassen They are dry systems the working fluid is CO2. Molten salt is no more a corrosion problem in a molten salt reactor than in a molten salt solar thermal system. The only difference is the heat source.
Great video and one of the first I've seen that shows a practical and relatively economic solution to the energy storage problem. This issue gets glossed over a lot when discussing renewables and real world solutions are required if moving away from fossil fuels is to ever be achieved.
I like that these tanks will be very cheap per kWh of energy storage; the expensive part is the charge/discharge rate. This sounds perfect for storing energy for days or weeks to allow renewable energy to be reliable.
Typical - we struggle for decades to figure out energy storage using the very limits of our technical abilities - meanwhile rocks were always good enough. The cats knew!! they snooze upon them in the afternoon!
@@hitreset0291 it's clean enough. Even cleaner than renewables (in terms of CO2/kWh, land footprint, biodiversity impact, resources used, deaths/kWh, etc), just look at the facts and figures, even the IPCC and IPBES recommend nuclear for its sustainable features. And I did not say it's storable, there's just no need to store when you can produce at will.
@@xtdyuoz123 Trouble is that nuclear had many of the disadvantages of fossil fuels. Hi tech and subject to political negatives surrounding its fuel source.
Interesting technique. Thank you for the video. What about replacing the basalt with liquid salt? In solar updraft towers they allready use salt water to store the heat.
This isn't a new concept and 60% round-trip efficiency isn't that great for pumped heat energy storage or PHES. Compressed gas has a far great efficiency look at Highview Power in the UK who have working projects as well as some large scale projects lined up.
Highview power has only 10% better efficiency, in the end it will come down to costs and we'll see in the next decade(s) who will win out or maybe both will.
Any system that relies on many conversions by the limitation of the physics processes will be very inefficient. Converting from wind or solar electric to electric, to heat and back to electric after that, that finally, and likely, will be used as heat again, is very inefficient proposal. Why not just store the heat directly, via solar concentrated, in a big, and well insulated thermal storage, and supply the community with winter heat. More then 75% percent of the consumed energy is being consumed in a heat form. Why the environment and the society need to pay the price of inefficient energy conversion systems we currently employ?
You are absolutely correct - this is the point - converting high grade work (electricity) to heat - only to convert it back to high grade work is fundamentally flawed. There has to be a better way for the wind turbine community.
Would be nice with a side by side comparison with the Highview Technologies liquid air storage. In your video about them, efficiency up towards 70% was suggested. With their simpler process, does this mean Highview would be more cost effective? Plus they extract co2 and water from the air, and could get an income from both.
That facility, remember, needed to be _HUGE,_ just saying... It seems like that initial investment would be the limiting factor to scalability. It wouldn't make sense to make small ones, is my point. The larger the facility, the more cheaply the energy can be produced.
Why would we ever want to go to 100% renewable? There is nuclear. Cleanest, safest, greenest form of power generation known to man, which is getting better all the time. Check out IMSR - looking at 4-5 p / kWh.. cheap as coal and gas. Your blinkered view towards renewables is disappointing.
I agree. Once wind or solar farms get colocated with grid scale storage then their base load output total cost / mWh can finally be compared with modular MSR as an apples to apples comparison. I believe that modular MSRs will win on cost and certainly on land use.
@@channguyen3349 That is great. But what happens when the wind stops blowing. I assume they'll be either storage / alternative supply. That'll need to be factored in to the cost per kWh.
@@rollinswitch Bogus? Really? It is actually quite generous to your point. 30% capacity factor for wind power generation is quite optimistic, and 60% efficiency for the proposed system is the maximum achievable, so 18% efficiency is the max you will ever have.
Interesting concept. Was consider to couple such with CSP. One question, will the rocks not crack into small stones due to thermal cycling? Probably need to replace rocks after some time.
You videos are always excellent but I found myself discounting this one because the theoretical efficiency is about 60% when grid level battery storage is already 80 to 90% efficient. Am I missing something?
Nope. Just that lithium ion still explodes. It's getting better, but that is what he meant by trading safety for efficiency. If it works well, it's inherently going to be kind of dangerous to handle and operate. Using not-dangerous materials that can be scavenged, is less efficient, sure, but doesn't require a giga factory. 🏭 Is the overall reduction in total emissions, cradle to grave, worth the safety increase and loss in efficiency?
I suspect it depends on whether you calculate efficiency as "watts out/watts in" or "watts out/$ in". IOW, hot rocks may be so much cheaper than batteries that losing 20% of the (fairly cheap) energy input is affordable.
I have some experience in power sector and mostly in control systems, but would be interested in seeing the efficiency and running cost of such system. Best part of this system is they use rocks readily available in the area, rather than a specific metal or element like other technologies than make scaling world wide not possible due to finite resources.
Using super low cost readily available, environmentally friendly materials, e.g. rocks for thermal energy storage is brilliant! Shuffling air back and forth between hot and cold storage tanks is a bit like a slow cycle Stirling engine with lots of thermal mass in the regenerator.
And you think nobody fought of that before?
Really?
You’d better look for answers why it has not been put to use.
It ain’t cheap, it ain’t super efficient, and it ain’t that environmentally friendly.
Start with the overall efficiency.
@@JDrwal2 Efficiency is NOT IMPORTANT here, these systems use energy from wind farms and solar that are being switched off because there is no where for the electricity to go. It’s more important to have a large volume of storage with a lower capital cost than Li Ion batteries than it is to be efficient. 60%:is approximately the same efficiency that is targeted for liquid air storage.
@@JDrwal2 Efficiency was important when you had to pay for every unit of energy consumed, back when big oil and big coal made the rules. In the renewable world, what counts is the cost per unit of power, not energy. Example: photovoltaics trumps gas generation despite one third efficiency.
@@JDrwal2 Please explain WHY it is not environmentally friendly, is there an endangered rock involved?
@@markotrieste power=energy, your comment is nonsensical. You literally just say you pay for unit of energy, not for unit of energy, so it's better.
Great video Dave. I work in energy consulting, and I use your channel as a launch point when I am researching emerging energy technology. It is difficult to keep up with the pace of development in energy, but your channel fills that breach. Kudos.
I wish my PM (Scott Morrison) would watch your videos. Recently he ridiculed renewables in defense of a proposed gas fired plant, "the sun is not always shining, the wind is not always blowing". There are SO many alternatives to fossil fuels we just need to choose which will be the most effective.
we dont even need to choose, we should support them all in parallel from yesterday onwards.... some will win, some lose, some will be very situational but we shouldn't fall into the incrementalist fence sitting that ScoMo is so expertly fond of
The man is beyond incompetent. Little Scotty from marketing hasn’t go the brains he was born with.
It is so wrong that we (Australian ) have such an idiot leading the decision process when most the science is clear that we need to change our energy policies fast !
Yeah. It is called Nuclear.
Just follow the money 💰
What sparked my interest immediately was how an aluminium or steel smelter could use their wasted energy in this tech. Also geothermal. Very good. A cost comparison between compressed air would be interesting.
Edit: I misunderstood, sorry.
No, the waste heat is only 75 degrees. Even it was 400 degrees or so, it is not usable for smelters.
However 75 degrees is great for heating existing homes and offices.
@@roland9367 he said "how the smelter can use it's waste heat" so you have misunderstood him.
He thinks the waste heat can be used as a booster , so the solar won't need to heat the rocks as much.
I think the future is going to be different generation systems that are site specific to what's needed, what can be used, and cost effectiveness coupled with a range of storage sites and redundancies that can communicate
Agree. Also wasted heat from nuclear power plants, and all power plants.
Always happy to see Yet Another Storage Technology come online, particularly one that doesn't contribute to the overall environmental contamination problem.
You happy to pay for it .Rest of use ain’t.
@@jimsouthlondon7061 Are rocks expensive where you live or something?
Why you fucking around with windmills and rocks just build another couple of reactors at Hinckley Point.
@@jimsouthlondon7061 We can now do better.
@@jimsouthlondon7061 Join the French in the war in Mali for uranium then. Where is the UK mine?
Dave, ur a star!! i find ur show in the top 10 of the entire iNet. the info you provide is top knotch, and ur delivery second to none.
keep up the good werk.
The clarification about long-duration for li-ion batteries was very helpful! Likewise, acknowledging the steep competition in the industry is appreciated, and some discussion of head-to-head comparisons would be really interesting as well.
You are my go-to channel for reality checks and Hope
Cheers Pierre :-)
This is exactly how I imagine large batteries. Pumps going back and forth. Was not expecting purely thermal storage, though - this could be built anywhere!
Check out on the economies of solar thermal molten salt storage. Under the hood the maintenance cost is the killer. The same here. Admittedly excellent thermodynamics on paper. Material science screams no no no.
@@cyklonetidalenergy7141 I assume the maintenance cost is high because of the molten salt being present in the pipes. If this system uses air, it doesn't seem like maintenance is any more burdened than that of empty pipes and containers? Though, admittedly, these pipes and containers do need incredible insulation.
Would like to hear more specifics (and links are totally fine) on what you are worried about.
@@cyklonetidalenergy7141 On the contrary . . . Almost all the components here are mature common parts. Pumps, heat exchangers, turbos, compressors. All already optimised and cheap.
@@andy_rb a water pump is a mature common part. A pump for 650° C hot corrosive fluids is not. That is the key point here I was trying to get across to people. Especially if you connect it to a storage going from deep frozen easy to crack metal and cycle and expand it including all required insulation up to 650° C in very short time. This thing is useless when it takes 12 or 24 hours to reverse the ops mode of the process. The rapid changes put a massive stress on materials in aggregates, pipes and containers. It can work for sure. Is it economical? maybe on the side of rather unlikely. Let's hope the best for them ... good luck. Enjoy the journey. Either they done calculations well or they did not care for sake of the highly desireable project goal impact. It impossible to understand what the true challenges are without testing and taking it step by step. The container casings and designs do require technical and material science niche expertise way beyond my scope. On pumps I have a lot better understanding and I know for sure they are far away from any commonly available parts you can just by off the shelf. There is very few stuff you pump that hot at all.
Then it comes down to sizes, cost and maintenance. Just compare to OTEC which is stuck for 3 decades now. Much simpler yet no progress on similar ends and means. Still just pumps and other off the shelf stuff at just normal temps.
@@buttonasas Air convection is a huge efficiency sucker and not what they speak about. You need a liquid other than water for this process for efficient heat transfer. Steam or ice both cause issues here. Eventually some kind of oil or molten salt will be used as a heat transfer medium. Not that environs friedly I guess.
As you spoke I was thinking in "Engineering with Rosie"'s video. Thanks for your continuous effort on he matter!
I put a link to her video at the end of mine.
@@JustHaveaThink Oh, thank you! I saw it.
I meant to comment that while you were speaking I was recalling Rosie's video that I had seen a couple days before... until you mentioned it. It was no coincidence!
Do we have any indication of the metrics..?
Capacity MWh/ ton or MWh/ cu’mtr ?
Charge/discharge power rate MW/ ton or cu’mtr ?
Capital cost estimates per GWh ?
Typical energy storage cost per MWh ?
Etc
This is a very novel approach to a heat exchanger, thanks for sharing!
👍🙏 So grateful for the work you are doing at this time we so need hope and focus on our energy transition.
So many heat-based storage systems coming up. I would never have thought that, of all things, heat would be such an attractive choice for energy storage (mostly because it seems the hardest to extract energy from).
ref 0:15
The predominant storage at the moment is water (pumped hydro). In batteries Li is off-course the dominant technology, but that is so fare just a small fraction off total storage capacity.
Yes, pumped hydro is what we have is Switzerland, the efficiency is around 60 to 70% but the infrastructure is enormous, a significant cost driver.
@@hernanposnansky4830 That odd since the older installation in Norway have a round trip efficiency of 84-87%. Newer installation 90-92% and added costs not that much since the generators are also the pumps. No added infrastructure needed.
NB: All installation in Norway is part of hydro electric power plant with dams.
bknesheim
I do not disagree with you.
I was refering to the average round trip afficiency at the point of insertion to the grid.
These are the particulars of the one of the older started in the early 1900's
The turbines are Pelton wheels, where obvoiusly separate multistage pumps and motors are required and in some cases very long distance from the dam to the actual turbine, which involves reversing the water flow. The older pipes had a smaller diameter, which create a larger pressure loss.
Remember that the flowrate for a given pressure (water level difference times dens. times g ) is proportional to the fifth power of the diameter in turbulent flow. Also the ' inertia ' effect due to reversal of the flow direction is inversely proportional to the flow area, in other words it takes some time to revert from production to storage, where the water flow is decreasing and is wasted because a pelton turbine operates at one exact speed ( one half the jet speed at the bucket radius) and the generator does not operate at partload efficiently.
These are not the only factors which determine the average roundtrip efficiency, Certainly newer installations and improvements are better. The other factor is the market, where short term power arrangements are made sometimes within hours. If you cannot supply , invariably you must avoid to waste stored water.
The operating company gets paid for delivered energy at the price negotiated in a short term, so economical decisions affect the operations greatly and that is reflected in what I called average efficiency.
Really cool how the stratified regions of each tank act as a kind of counter-flow heat exchanger. If your reference frame follows the transition region, you can think of the air flowing one way while the rock flows the other.
It is actually the exact opposite of the usual counterflow heat exchanger (or a countercurrent solvent system).
Those are designed to keep the change in temperature (concentration) as small as possible at each point.
In contrast this system tries to maximise the change in temperature at each transition. They hope thereby to improve the over all efficiency.
I don't myself know enough thermodynamics to grasp why in some processes (like this) it is efficient to have big temperature changes and in others (where counterflow is favoured) it is better to keep them small.
@@trueriver1950 No. It is a counterflow heat exchanger. The key characteristic is that the media flow in opposite directions, with one end hot and the other cold. The media thus swap temperatures. The difference in temperature between the media at any particular point is small, but the overall temperature difference between one end and the other can be as large as you like.
In this case the rock doesn't actually move, but that's just a matter of reference frame. There is a narrow band over which the temperature change occurs. Follow this up or down during charge or discharge, and the rock can be considered to be flowing in the opposite direction to the air.
You should interview the ETES team from Siemens gamesa. They have worked significantly on this idea and have built a demonstrator in Hamburg:)
It is a different idea, but yes with similarities.
Love this channel. And Henrik Stiesdal is one of the most inspiring individuals in the wind industry!
It is certainly an concept that needs to be explored and on paper it seems like a good idea but with my experience with any heat recovery system is the initial build cost on going maintenance cost and it's longevity against all its returns which don't always reach the projected forecasts. Keep up the good video commentaries and stay safe.
Been very focused on clean energy since the late 60’s - having a front row seat of this massive impending disruption is awesome! Particularly as a mechanical engineer. The rate of innovation is incredible!
Innovation.? Or rather designs having their 15 mins. It's not the innovation, it's their adoption. The spotlight, how ever powdered, has been turned on.
@@robertwoodliff2536 Oh I think there has been some pretty serious innovation happening Robert - I'm a mechanical engineer, I did my thesis on windpower in 1981 - the innovation in the energy space has been brilliant!
Your career would have been far better spent working on nuclear power. Too late now anyway.
@@garry8390 Seemingly not. Innovation & adoption in renewables is far out pacing that in nuclear. I guess nuclear’s future is looking uncertain at best?
@@nicennice what seems and what is are two very different things. Renewables are bullsh*t used by crooks to suck up public money but by the time you wake up and realise it will be too late.
Thank you Dave for your reliable excellence during these critical times.
Great Video! I am happy that there are so many people working on these problems.
Great video, it was really cool to see a follow up of the progress Bo and the Gridscale team have made since I visited them nearly a year ago. So cool to see they've got a pilot project coming, I thought at the time that they were well set up to move fast and it seems they have done just that. Also... I am in awe of your animation skills - are you still doing these yourself?!
This vid is from today. (September 19) How did you manage to respond 3 days ago?
@@Skoda130 Oh, wow... Good catch. I see it as 3 days old too...
@@Skoda130 UA-cam videos can be viewed with secret links before they are scheduled to be published. It's honestly beyond me how so many people still don't know this is a thing.
@@theamici because i never can view any youtube videos in that manner.
If you are a patreon of the channel you can view this earliest
Brilliant work. Had I had videos like yours when I was a lad, I'd have gone to university.
Your videos help me feel more optimistic about the future. Thank you.
I like listening to smart people like this dude
There was an English startup 10-15 years ago based on the same approach, but seems they faded into oblivion. I'm glad to see another startup making good progress. When I did calculations on the prior startup it seemed quite reasonable with a pair of building sized storage units (for hot and cold) not taking much area, and claimed round trip efficiency quite high. The Stiesdal claim of 55-60% seems competitive with iron-air and other technologies emerging for longer term storage. Insulated rocks are pretty cheap-- the 10EUR/kWh is pretty amazing. I wonder what the cost/W for the turbine-motor-generators is. This seems much more practical than liquefied air or CAES. Gravity batteries are not even close in cost and size, except maybe the electric train up a mountain.
That’s very interesting how the lion storage should work in tandem with these heavier grid scale applications. That immediate management of frequency was highlighted in a talk about why hornsdale was so successful. An idea for a video may be to build a table with all these solutions listed along with properly levelized cost per kWh? Very exciting stuff!
LCoE for storage doesn't really tell the story. Hornsdale paid of it's CAPEX within a two years, ROI that is unheard of in the energy markets, primarily because they were the first on the NEM with this technology and stitched up a sweet deal with the SA Government for ESS in addition to playing the FCAS markets.
@@alastairleith8612 yes Toni seba was pointing out the lcoe is all wrong so I am speaking loosely here hoping to see leveled cost properly calculated and compared for the different propositions, many thanks
the cost to convert sea water into hydrogen power plants is cheaper and more efficient, lol
Yet again, I've been both enthralled and enlightened! Thank you once again for your fascinating insights!
Cheers John :-)
Roomrater: 10/10 great video and well presented. 👍
The Ambri liquid-metal battery seams to be a mechanically simpler system that would require far less maintenance and greater safety. But the key maybe to have multiple options in long-term storage that may be preferable in a variety of locations. I can see the Ambri liquid-metal batteries being ideal in remote locations powering small communities, such as the Canadian Arctic, replacing or augmenting diesel generators.
I'd agree the Ambri battery is exponentially an easier system to use but I'm thinking it's going to degrade its ratings if you begin using the heat that it requires to work, for other purposes. It may have some heat that can be taken but I'm guessing it's not going to heat an artic town
Brilliant. Great to see such innovative solutions coming closer to supplying grid scale storage.
crushed rocks is innovative?
I reckon this will give about 20 Wh/kilogram, vs 100 to 265 for Li-ion (have they made claims about this?). To compare with gravity storage, it's fun to divide these by gravity to convert them to heights. 20Wh/kilogram is about 7km. 265 Wh/kilogram is 97 km (i.e. a lithium battery powered elevator could get most of the way to space)
If you are not going to move the battery it doesn't matter how much it weighs. What matters is Wh/$ not Wh/kg.
@@adrianthoroughgood1191 Indeed, though there is still going to be some upper bound. I just thought it would be interesting to calculate...
@@Aaron628318 Wh/m2 could be more of a concern in areas with limited land availability. But since solar and wind also need large areas of land compared to a traditional or nuclear power station if you can site them together this may not be a problem. It's good from a grid point of view to have them together because it takes away some of the variability of current leaving the site. Can't do that with offshore wind though!
There are a lot of hot rock proposals around, but in my view there needs to be a phase change to make it efficient. You also need to consider whether you would be better off storing excess energy chemically, eg. as hydrogen or ammonia.
I've been watching your videos for quite a while now and didn't realize I hadn't subscribed. I get all your notifications anyway, UA-cam knows. I HATE it when people beg for subs or ask you to subscribe because most people just do it in a very offputting way. You're definitely not one of those people and I am now subscribed. :) 500k subs should be just around the corner
In the coming years and decades filling stations are going to have a lot of large tanks under ground made redundant by electrification. Given that nearly all these stations will have at least two of these tanks for petrol and diesel, could these be converted for use in this sort of system?
I doubt there would be much point. To store gasoline at ambient temperature, and air at 600 C are probably going to need entirely different materials.
No, totally different application.
when these stations are closed the tanks are normally dug out finding a seconde life would be good if not suitable for this maybe flow batteries?
Thanks for the most pleasing discussions without political rhetoric, yet with the facts about reducing our impact. We humans have always improved - it’s what we do - by considering better ways, always. It’s done by sentient, caring discourse like this.
I'm always amused when PV solar is used to electrically heat a medium in order to store energy. I'm not saying it's a bad idea and it allows it to work in concert with wind. However, it seems like if the solar is solely charging this system, wouldn't it be immensely more efficient to use solar thermal to heat the medium, or maybe a combination of the two so as to maintain the wind inclusion. Just a thought.
This is _not_ electrical (ohmic) heating. It's effectively a heat pump/heat engine to create a temperature difference as storage (note that the cooler of the two tanks is _colder_ when the system is charged). If the ideal case is considered, there are no losses.
For efficient energy out of thermal you need a high temperature gradient. You need 600 or even better 1000 degrees of Celsius to drive turbines and store energy. There are some new projects for solar concentration towers. They are more expensive than pv but are practically production and storage in one. The heated up molten salt can drive air turbines with a heatexchanger, but also store the heat, to let the turbines run in the evening and over night.
I guess the idea is not that there are dedicated PV modules installed only to provide heat.
Instead, if you have a grid with a lot of wind and solar then you will have times of excess production (e g. at noon) during which this kind of system will be charged.
In northern countries like Denmark- there is not much sun in winter. But there is a lot of wind energy generation (often more than needed), and there is a need to store that energy, as generation is uneven. I'm certainly interested for this in Lithuania, as some grid balancing solutions are needed if we want to expand our wind energy generation, to proceed with the plans with building offshore wind farms this decade.
Kinda like they do in Spain with using the sun to heat molten salt.
Excited to see Rosie's video next!
Could you add the link to the description or a pinned comment?
Yes, I will do that.
Seams like we are finally getting somewhere with renewable energy. Too bad this did not happen 30 years ago...
Until people actually started to see the consequences of climate change no one had the impetuous to do anything. Humans never take action until issues become a crisis.
It probably did, the level of oversite of what public officials could sweep things under the rug, so to speak, is mind boggling! The state has always maintained that state secrets protecting us and our freedoms seems to be getting thin for us but it sure protects them from either incompetents or pure coruption, considering that the “terrorists” always succeed in taking away our freedoms in how we have to give them up to the state so the state can protect us from who the state went out of their way to create in the first place!
You can thank the fossil fuel industry for that.
I agree that these developments are coming very late in the game. Also, they need to be accompanied by a radically scaled back expectation for never-ending growth on a finite planet (one of the fatal flaws in capitalism that have already driven us to ecological overshoot).
They basically use off the shelf components that are used in the industry for decades. The systems weren't interesting before, because the renewable production capabilities weren't there. Storage is only needed when we shut of fossil fuel power plants.
Another optimistic video. Ahhh... we need it. I'm getting to the point where the doom is sending me over the edge. Cheers Dave for all the reasearch and clear presentations.
Way back in the 1990's several advocates of compressed air storage technology were talking about similar systems but they were shouted down by the electricity only solar and wind people. The idea of putting a compressor not a dynamo in the windmill meant you could store the air. Running chilled compressed air though pipe at the focus of a solar concentrator would produce more stored energy. The world decided to go down the path of electricity only and so these kinds of pneumatic and thermal solutions have been ignored for 30 years.
Thank you Just Have A Think for all the very interesting & useful info. You may have already talked about this but I wondered what thinking there is about flywheel energy storage as I here very little if anything about it on the media.
Would be great to see a comparison of Lithium Ion verses Lithium Phosphate batteries for EVs and quick energy draw. Also a comparison of Zinc-Air Flow, Iron Flow, Zinc Bromine Flow, etc battery systems for long-term storage.
Flow batteries and liquid air batteries are the way to go
Oh man you read my mind!! Please do this good sir!
Interesting solution to the storage problems
Thanks for sharing your thoughts with all of us 👍😀
As one smart man said:"if you want dirt cheap battery, it need to be made out of dirt" I see they followed his advice here
This a common theme -being developed from Perth to Stockholm.. Basalt, Haematite or Silicate sand.
Your name is helpful.
@@dac545j doing my part)
Donald Sadoway
@@hernanposnansky4830 oh yeah thanks dude! Following his ambri project, hope he succeeds
I have a long duration energy storage medium: uranium, plutonium, and thorium. They store the energy of a supernova that happened 5 billion years ago. 🤗 We need load-following liquid metal cooled fast breeder nuclear reactors to balance out renewables.
There is this company Advanced Metallurgical Group that is developing lithium-vanadium hybrid batteries for industrial purposes. Pretty interesting.
Not rly
Great to see these inventions. Hope they launch them soon.
This seems like a promising concept. Though whatever happened to the compressed air energy storage system? Also a modular and scalable grid sized energy storage solution.
mi point,compres air more better 60% without complicated sistem, ofcurs if reheat is done with ambient air the% is better ,and if windmills compres the air directly % increase,no storege loses,but no patent ....
Isn't Highview Power basically using the compressed air idea (but storing it as a liquid)? Not sure what they claim as their operating efficiency, but maybe around 60% too?
@@yvanpimentel9950 Critical is the energy density which is low for compressed air. As a result, the cost of storage, in my opinion, will be significantly higher for a warehouse that is to have an energy reserve of several days.
@@lawrence18ukThis company cheats a bit because the efficiency is similar when you have waste heat at your disposal. "In isolation the process is only 25% efficient, but this is increased to around 50% when used with a low-grade cold store, such as a large gravel bed, to capture the cold generated by evaporating the cryogen. The cold is re-used during the next refrigeration cycle.[3]
Efficiency is further increased when used in conjunction with a power plant or other source of low-grade heat that would otherwise be lost to the atmosphere. Highview Power claims an AC to AC round-trip efficiency of 70%, by using an otherwise waste heat source at 115 °C" . All these systems are so-called Carnot batteries. I believe that this is the best solution to the question of which one will win.
The compressed air system is being built near Manchester, UK. Hopefully we’ll see some results soon. Hopefully there will be room for many many of these different technologies going forward.
Brilliant Idea, these are the kind of news that makes my week. Thanks so much for the program for the research and for explaining so clearly and simple that anyone can understand.
Once again, thanks so much for the great effort in this program.
Have just discovered the notion of using ammonia as a fuel - especially in the shipping industry. A friend who is working on a pivot to carbon free everything mentioned it and I had never even heard of it! Would love an article on shipping and/or just ammonia as a fuel if it appeals. :)
One thing is you need to get z handle on is the nitrous oxide component as the waste gasses of the combustion process. Unless you can run the exhaust through a catalytic converter maybe.
Ammonia as a fuel is a bad idea - it's well regulated at the moment because of its potential to be used in explosives.
Making it a fuel source would make regulation a much trickier problem.
@@mnomadvfx
Plus you are using it for fuel aren't you generating NOX from the combustion process.
Super Video. Strange that I have to find out, about this on you tube, and not on Danish T.V. I will go down, and check out the operation. What an exciting project. Thanks for the video. 😘🙋🏻♂️
Whenever a new technology is presented,
it is tempting to jump to a conclusion. JHAT resists that temptation and presents the facts objectively. In contrast, many posts on social media are hasty reactions which attempt to champion one technology over others, based one particular characteristic. This should not be a binary debate.
Dave's introduction explained that an energy storage technology might be optimised for one or two desirable characteristics, but cannot deliver them all.Therefore we should expect energy grids to utilise several technologies to generate, store and deliver power. We should be aware by now that there is no 'one size fits all' solution to sustainable energy. So let's keep an open mind to the possibilities offered by all innovations. Technologies that may appear unpromising when viewed individually, might prove very effective when combined.
Well put. The current multitude of potential solutions will be whittled down to a relative few that utility companies can choose from based on cost, local natural resources, performance requirements etc.
I agree with your sentiment, but the fiasco of Theranos shows the danger falling for "game-changing"/"revolutionary" "hypes" that do not, in fact, stand up to honest, unbiased scrutiny. Capital investment is a finite resource - we can't afford to throw money at people and designs that never leave PowerPoint slides into practical prototypes. Case in point: the "bladeless turbines" that this channel promoted which have no chance of delivering what its creators claim in real life conditions - the numbers simply do not add up.
As always a very well put together video, change is well overdue, the whole system has to be more efficient, hurra !! for brilliant brains
I love your Channel but...
In the analysis below, I am assuming that the second law of thermodynamics does not exist, so that there are no energy losses. The specific heat of basalt is 840 Joules/Kilogram/degree C. The specific heat of granite is about 800 Joules/Kilogram/degree C. So a differential temperature of 630 degrees C means that 1 kilogram of basalt can store 840 * 630 Joules = 529,000 Joules of energy. One Watt is a Joule/second, so 529,000 Joules can deliver 529 KW for one second. But one day is 86,400 seconds long! So 1 Kg of basalt can only deliver 0.0061227 KiloWatts for an entire day. Since the average American household uses about 30 KiloWatts each day it means that you would need about 4900 Kilograms of basalt to run just one house for a day. If you include the second law of thermodynamics, you probably need to multiply that number by 3.
We have run out of time. Yes, we can use wind and solar during the day and on windy days, but for long-term base energy, we need molten salt nuclear reactors. We can only get about 2 eV of energy per atom out of the chemical energy found in batteries and even less from thermal atoms bouncing around. But when you fission a single uranium atom, you get 200 million eV of energy or 100 million times as much energy! We have enough thorium and uranium to run the world for hundreds of thousands of years. With molten salt nuclear reactors, we just filter out a few kilograms of fission products each year and store them for 300 years in my backyard after I make a few trips to my local Home Depot. We can either use those atoms today as a preventative measure or in 100 years as a desperate measure to try to stop the Earth from becoming another Venus. We have already lit the fuse. There are huge amounts of carbon up in the Arctic in the permafrost that we have been stockpiling for the past 2.5 million years during the Ice Ages of the Pleistocene. Once that bonfire starts up, we will have lost all control.
These are not normal times. We are all living in a historical crossroads of humanity. Are we going to make it or not? Unfortunately, I believe that this is why we see no evidence of Intelligence in our Milky Way galaxy. All carbon-based forms of Intelligences always kill themselves off before a machine-based form of Intelligence can arise. Because the Darwinian processes of inheritance, innovation and natural selection require many billions of years of theft and murder to bring forth a carbon-based form of Intelligence, it seems that all carbon-based forms of Intelligence have a real problem with turning off the theft and murder in time to save themselves.
Regards,
Steve Johnston
I agree about our proximity to Arctic Tipping Point (and oceans and Amazon) and need for acceleration of new nuclear.
Unfortunately the window is narrowing I believe and we have spent and delayed the social capital in other ways.
Your maths is wrong. You divided kilowatts by time and got kilowatts when you should get joules.
Check those numbers again. It certainly takes a lot of KG of basalt at 630 deg Celsius differential to power a 30kwh a day use-home. But it’s about 203 KG at 100% efficiency or 340 KG at their 60% efficiency goal (assuming the waste heat is not used elsewhere).
340 KG per house is still a lot but way better than 4900 :)
I agree the situation is dire and alternatives like fission need to be embraced. Also radiating waste heat at 8-3 micron into space instead of just shuffling it around (like home Air conditioning) is another thing individuals and business can be doing soon.
Didn't his bits about temperature gradients, at 5:30 mins, ish, and insulation at 6 :03 mins ish , address your concerns ?
If not, why not ?.
I suspect the galaxy is full of dead civilizations as well...
You've come a long way baby Excellent work
I remember when you 1st started you were working on your backdrop
Now you're interviewing industry leaders Is awesome
Looks promising. I hope it's adopted en masse in the years to come.
I sure do appreciate your channel. Thanks for delivering such interesting content!
Interesting. I would like to see some numbers. For a given kWh amount of storage, how big would the cylinders be, and what range of kW power output would be expected?
I've just done some back of the envelope calculations.
Assumptions: provide 1 GW for 1 week, basalt specific heat capacity 2 kJ/kg·℃, same for the cold reservoir (which need not be basalt), 50% fill (need air gaps in the rock for the hot/cold air to travel through), 600℃ hot and 385 ℃ cold as given, generation efficiency 20% (from the website). (Note, the temperatures at the input and output of the generator are the relevant ones, not the -30℃.)
The calculations work out to just over 10_000 cubic metres, about 10 Olympic swimming pools' volume. (Using a cubic meter to swimming pool calculator I found on the web.) That's inside the insulator, so add maybe 20% - 30% to that for total volume. And then another 50%, say, for contingencies.
1 GW is roughly a "typical" thermal baseload power station these days, although newer ones tend to be bigger. The internet seems to think it's enough for 300_000 homes, so taking non-residential use into account, enough for a small city of 150_000 to 350_000 people (maybe).
It's a lot smaller than I thought it would be, so I've probably missed a power of 10 (or two) somewhere.
Edit: on rechecking the specific heat capacity of basalt is more like 0.8 rather than 2, so multiply the result by 2.5. 25 swimming pools.
@@gregvanpaassen My b-o-e calcs suggest that about 1E6 m3 would be needed to store these E15 J. About 100x more than yours. One or both of us is astray! Which for me reinforces that for this video to be useful it really needs to provide an example with numbers. A good device that is impossibly large is not very useful. But then your example suggests storing the output of a nuclear power station for a week. That is huge.
The same amount of energy stored in diesel fuel would require about E4 m3? A lot smaller, if still huge!
I think the essential issue here is that existing liquid fuels have high energy densities that are very difficult to achieve my other means. We find this hard to believe.
@@gregvanpaassen Plus point is that everyone can have free hot water: Denmark is so expensive!
@@gregvanpaassen Good calculating but one week is too short, more like a month, at least. UK wind farms have been running at less than 25% usual supply for last month or more.
@@jimgraham6722 Sure! I just used a week for the purposes of getting a sense of the size needed. I agree that it's too short for reliable supply from wind, without huge investments in long distance, international transmission lines.
Thank you for another wonderful video. And thank you for explaining the process in detail like that. You always do such a wonderful job of avoiding jargon and getting to the heart of how things work.
It's interesting that this concept doesn't rely on some new breakthrough or previously ignored technology to work. It's put together from common components and the innovation is in the process itself: all the heatings and coolings and the various machines that are plugged in between the tanks. It may be rated for 10 000 cycles, but if the only real points of failure are the compressors and expanders and generators, you could just swap them out for new ones when they age and keep going on and on. The rock inside the tanks may erode into smaller pieces eventually from all the thermal expansion and contraction, but that wouldn't change it's heat capacity.
The problem with any grid scale long duration energy storage scheme is that you get diminishing returns from low utilization of long duration capacity and you still run out of capacity for longer durations.
Another brilliant video! Was on Lolland in July. Very pretty (and incredibly flat...)
60% Efficiency will hurt the bottom line in many places. But if it's sufficiently cheap will still have it's place in the system. Nice.
60% efficiency actually seems really high.. Any energy converter has more losses than that. But maybe I’m comparing apples and bananas?
60% is a break point as this is about what you get from gravity pumped water systems which dominate the grid scale market at the moment.
Really interesting - thermal storage like this was being developed in the UK years ago, but it’s good to see the Danish are bringing something to market.
Could this machine also make use of “waste” heat from i.e. Datacenters?
Well the system doesn't take in heat but rather electricity...
too low grade ... you can use that sort of heat in a pre-heat of space heating for another facility, or water before final temp raise.
@@mju135 i get that… what if the air it takes in is pre-heated? Wouldn’t that make it more efficient?
I guess sensibly using that heat directly would probably make more sense, but still… if no other use for the heat can be found maybe this could be useful?… 🤷♂️
@@gorgonbert you'd have to have the data center and the energy storage facility built right on top of each other though.
called junk heat because it lacks intensity to be of much use. Usually preheating but if the temperature differences are low, just the energy in moving the air around might eliminate any benefit.
Excellent bravo team!!! The real facts!!! Move forward with proven efficiency!! And unity! Marvellous education!! Channel
CAES (Compressed Air Energy Storage) is far simpler. I can only see this suppasing CAES if energy efficiency is far superior.
That said using the waste heat for local area heating systems may be the best replacement for gas heating over the next 20 years.
60% is pretty good for long term storage. I've not seen any efficiency claims from the compressed air marketers so I suspect it is are quite a bit lower. Do you happen to know?
@@w0ttheh3ll another problem with compressed air storage is actually having a place to store the air. what I've seen usually involves underground storage which could be limited by location.
An advantage of this over compressed air is that the pressures are much lower. P1V1/T1=P2V2/T2 gives a pressure rise for the main energy input circuit between 1 bar at the inlet temp of 385C(658K) and 1.3 bar at the outlet 600C(873K). So say design the tanks for 2 bar, which will be trivial. Compressed air needs several orders of magnitude higher pressures to be useful, with associated structural challenges.
Heat capacity of rocks is much higher, but water is the best.Only problem is water cannot be kept liquid much above 300C
Not really, it kind of the same thing as you have to heat the air as the pressure drops or it will cool and you lose all the efficiency. This is essentially that, but with heat recovery.
At 0:12 the predominant grid scale energy storage medium is large storage dams that provide seasonal water storage for drinking water and irrigation which also have Hydro Electric Power stations. These are supplemented by Hydro Electric pump storage which provide additional output. In the UK hydro power resource is limited and some of the resource remains undeveloped due to resistance from people who want to keep wild places natural.
New York state and the UK are building compressed air storage. It's the same concept and scalability without the rocks. Plus it's all off the shelf parts, just steel no rare elements.
No reason to have huge stationary lithium batteries all over the place. Some of the place sure
Sounds like an explosion in the making.
Please review all these with the economics and findings from commercialisation trials - that would be fantastic!
No sense in lying,I cannot honestly claim to understand this system. Apparently the inventor knows what he is doing,so I must do more research. Thanks for an interesting and educational video!
Me neither. This presentation is lacking in demonstrating just what creates the potential energy reservoir. I’ll have to find out elsewhere.
If you are in any way MINT-inclined, I would suggest you watch an online lecture on thermodynamics and check out how thermodynamic cycle processes work :)
Another very interesting development in the energy storage area. 😃👌👌👏👏👏
I like the concept, but since windmills tend to become larger and higher, I wonder if it would not be viable to have a weight towed up using the excess energy when demand is low and wind is blowing and then lower the weight when there isn’t enough wind but energy demand is high.
Try to imagine the engineering challenge involved in that; it just isn't economical in my opinion (but I'm not an engineer). Do your own calculation for Gravitational Potential Energy (it's a pretty basic calculation); you'll see there is very little energy stored by raising mass. For example, a 1 metric tonne mass raised to 100m contains roughly the same energy as just 3 or 4 laptop batteries.
@@gregx1044 you’re absolutely right Greg. One ton raised 100 m only has a potential energy of a measly 0.27 kWh. I should’ve done this back-of-the-envelope calculation first.
@william breen Thanks William. ThunderfOOt happens to be my debunking hero. But I hadn’t seen that video yet.
Its a brilliant and very promising idea. May not succeed at first, but the basic concept is very solid. Flexibility, availability and cost are all very favorable. Crossing my fingers here.
I never fail to gain fresh insights by Just Having a Think
A really cleaver and interesting idea, hope it scales well and brings battery tech costs down.
I'm looking forward to Liquid Fluoride Thorium Reactors (LFTR): ... Screw this noise about wind and solar, or compressed air. In Europe there's a lack of wind and now they need to lite up the gas fired plants. And what if we have a large scale volcano event.... bye bye solar. Batteries are needed to mitigate variances in power and load in the grid. The Stiesdal system looks like a maintenance nightmare. There are only two current large scale compressed air systems operating. One in Germany the other in Alabama. Both are over 20 years old.
#LFTR
I don't see the maintenance issues, pumps, turbines, and pipes are all well developed technologies.
We run turbines in hydroelectric dams or natural gas plants for decades, they have been very stable and reliable.
Admittedly components operating at 600°c may wear out more quickly.
Maintenance nightmare?
In addition to what Doc Watson says, LFTRs also run at about 650 ℃. Instead of air compressors and expanders they need fancy water purification systems for the steam, and steam turbines which run at pretty much the same temperatures as this system. And then there are the systems for pumping around the hot, corrosive, radioactive molten salts, and filtering and purifying them.
Those latter systems are the maintenance nightmare. This system uses temperatures, machines and materials with which we have many decades of experience.
@@gregvanpaassen They are dry systems the working fluid is CO2. Molten salt is no more a corrosion problem in a molten salt reactor than in a molten salt solar thermal system. The only difference is the heat source.
Great video and one of the first I've seen that shows a practical and relatively economic solution to the energy storage problem. This issue gets glossed over a lot when discussing renewables and real world solutions are required if moving away from fossil fuels is to ever be achieved.
I like that these tanks will be very cheap per kWh of energy storage; the expensive part is the charge/discharge rate. This sounds perfect for storing energy for days or weeks to allow renewable energy to be reliable.
How do you know this will be cheap per kWh ?
We have no information or data on costs for that so far
Love the concept! Not sure if it will gain enough traction to be widely accepted. Very good video.
Typical - we struggle for decades to figure out energy storage using the very limits of our technical abilities - meanwhile rocks were always good enough. The cats knew!! they snooze upon them in the afternoon!
The rocks are the easy part. The compressor and expander is where the engineering development is.
More like - we struggle for decades to figure out energy storage, when we can have clean on demand nuclear energy ...
@@xtdyuoz123 nuclear is far far far from being a clean source of energy. And NO it is not a storage solution.
@@hitreset0291 it's clean enough. Even cleaner than renewables (in terms of CO2/kWh, land footprint, biodiversity impact, resources used, deaths/kWh, etc), just look at the facts and figures, even the IPCC and IPBES recommend nuclear for its sustainable features.
And I did not say it's storable, there's just no need to store when you can produce at will.
@@xtdyuoz123 Trouble is that nuclear had many of the disadvantages of fossil fuels. Hi tech and subject to political negatives surrounding its fuel source.
Interesting technique. Thank you for the video. What about replacing the basalt with liquid salt? In solar updraft towers they allready use salt water to store the heat.
This isn't a new concept and 60% round-trip efficiency isn't that great for pumped heat energy storage or PHES. Compressed gas has a far great efficiency look at Highview Power in the UK who have working projects as well as some large scale projects lined up.
Highview power has only 10% better efficiency, in the end it will come down to costs and we'll see in the next decade(s) who will win out or maybe both will.
Pretty useful idea. You could see this one actually using the waste heat from any number of industrial or residential settings.
Any system that relies on many conversions by the limitation of the physics processes will be very inefficient. Converting from wind or solar electric to electric, to heat and back to electric after that, that finally, and likely, will be used as heat again, is very inefficient proposal. Why not just store the heat directly, via solar concentrated, in a big, and well insulated thermal storage, and supply the community with winter heat. More then 75% percent of the consumed energy is being consumed in a heat form. Why the environment and the society need to pay the price of inefficient energy conversion systems we currently employ?
Well, it sounds good and we can spend $$$$$ umpteen billions so it has to be built.
You are absolutely correct - this is the point - converting high grade work (electricity) to heat - only to convert it back to high grade work is fundamentally flawed. There has to be a better way for the wind turbine community.
Super cool. Hot rocks! Let's get rolling.
Looks promissing.There are small scale heating systems that use crushed rocks for domestic heating which this reminds me of.
Would be nice with a side by side comparison with the Highview Technologies liquid air storage. In your video about them, efficiency up towards 70% was suggested. With their simpler process, does this mean Highview would be more cost effective? Plus they extract co2 and water from the air, and could get an income from both.
That facility, remember, needed to be _HUGE,_ just saying... It seems like that initial investment would be the limiting factor to scalability. It wouldn't make sense to make small ones, is my point. The larger the facility, the more cheaply the energy can be produced.
Why would we ever want to go to 100% renewable? There is nuclear. Cleanest, safest, greenest form of power generation known to man, which is getting better all the time.
Check out IMSR - looking at 4-5 p / kWh.. cheap as coal and gas.
Your blinkered view towards renewables is disappointing.
Nuclear is the only technology capable of actually de-carbonizing the atmosphere.
I agree. Once wind or solar farms get colocated with grid scale storage then their base load output total cost / mWh can finally be compared with modular MSR as an apples to apples comparison. I believe that modular MSRs will win on cost and certainly on land use.
4-5 p/kWh, that is expensive. I am paying 3 p/kWh for windmill produced electricity at the moment.
@@channguyen3349 That is great. But what happens when the wind stops blowing. I assume they'll be either storage / alternative supply. That'll need to be factored in to the cost per kWh.
Beautifully explained... again.
Cheers Drawn :-)
Why would a 100% renewable energy grid be a goal? 100% CO2-free I can agree with…
Nuclear, as it exists, does not scale, is highly expensive, wasteful and dangerous. So until major advances are made the aim is at renewable energy.
@@rollinswitch But windmills with life length of about 20 years, accompanied by storage systems that don’t even exist yet is cheap?
@@rollinswitch Capacity factor of 30% and storage efficiency at 60% yields overall performance of 18%, that sounds like a solid solution.
@@TeslaLegend Bogus math.
@@rollinswitch Bogus? Really? It is actually quite generous to your point. 30% capacity factor for wind power generation is quite optimistic, and 60% efficiency for the proposed system is the maximum achievable, so 18% efficiency is the max you will ever have.
Interesting concept. Was consider to couple such with CSP. One question, will the rocks not crack into small stones due to thermal cycling? Probably need to replace rocks after some time.
Brilliant work. Keep up the very informative videos.
What we are looking for is 100% house independence energy needs from outside sources.
@Peter Pebbles not apreciated potentiality of geothermal energy.
You videos are always excellent but I found myself discounting this one because the theoretical efficiency is about 60% when grid level battery storage is already 80 to 90% efficient. Am I missing something?
Nope. Just that lithium ion still explodes. It's getting better, but that is what he meant by trading safety for efficiency. If it works well, it's inherently going to be kind of dangerous to handle and operate. Using not-dangerous materials that can be scavenged, is less efficient, sure, but doesn't require a giga factory. 🏭
Is the overall reduction in total emissions, cradle to grave, worth the safety increase and loss in efficiency?
Yes, Price
I suspect it depends on whether you calculate efficiency as "watts out/watts in" or "watts out/$ in". IOW, hot rocks may be so much cheaper than batteries that losing 20% of the (fairly cheap) energy input is affordable.
2160p definition video.......amazing !!!!
Thanks for your knowledge sharing
I have some experience in power sector and mostly in control systems, but would be interested in seeing the efficiency and running cost of such system. Best part of this system is they use rocks readily available in the area, rather than a specific metal or element like other technologies than make scaling world wide not possible due to finite resources.
Interesting,thanks for bringing this positive tweak to the future,too our attention
Wow, this is impressive, a rechargeble 'mobile' geothermal battery. That is innovative.