Limestone-based Thermal Battery

Calliban · 2023-06-27 13:01:44

Terraformer, you do get higher efficiency if the vehicle carries both a hot and cold source. The downside is that you carry twice the mass. It dillutes the energy density of an already diffuse energy storage medium. But for stationary energy storage, this could work. A heat battery, consisting of two phase change materials, can be optimised for efficiency between the two specific melting points. Also, it makes a great deal of sense building systems that can use both hot and cold. For example, a refrigeration unit could supply hot wash water to a building. If we ever build a liquid N2/air powered transportation system, the liquefaction facilities will produce a great deal of waste heat that could be used for space heating.

SpaceNut · 2023-06-27 19:44:13

I can see a fluid exchange system becoming contaminated over time and not being of quality water that we would desire for this heat storage type possibly sea water versus fresh would cause many issues for this as source are no longer what we wanted.

I did look at heat pump water heating and it only outputs 90 'F water so this is a preheat level for home use.

As Calliban, notes we are substituting mass of engine, fuel and other devices in exchange for the mass of an alternative powering system.

SpaceNut · 2023-06-29 23:09:49

Going back to the heat pump or AC parts the main item in the solar units make use of a scroll compressor pump as the turbine to create power from the freon or other gas expansion.

https://www.sciencedirect.com/topics/en … ompressors

https://mechanicalboost.com/scroll-compressor/

ngcb2

All You Need to Know About Air Conditioner Components

8 Main Parts of an Air conditioner

5 MAIN PARTS OF AN AIR CONDITIONER AND WHAT THEY DO

ac-installation-diagram-data-wiring-diagram-today-auto-ac-compressor-wiring-diagram.jpg

Calliban · 2023-06-30 09:31:47

Nate Hagens, Simon Michaex and others discuss the problems with attempting to decarbonise transportation using EVs.
https://m.youtube.com/watch?v=5stPFdegJpg

In short, the people pushing this as a solution, really havn't done much background work. There isn't anywhere near enough mineral mining capacity on Earth, to build even one generation of EVs and renewable energy infrastructure. If every automobile became an EV tomorrow, it would reduce Europe's consumption of oil products by 25%. That is even less impressive than it sounds, because we would then need a disposal route for gasoline and diesel, which would end up being waste products from the refining process. We would probably end up burning gasoline to generate the electricity needed to charge EVs when the wind isn't blowing.

All of this aside, assuming we can replace all passenger cars with EVs (at no extra carbon cost) and all electric power used to charge them was carbon free. Global emmissions would decline 8%. Given that electricity is not carbon free and EVs have a lot of embodied energy, is is doubtful that an EV revolution woukd reduce CO2 emissions at all.

Last edited by Calliban (2023-06-30 10:14:34)

kbd512 · 2023-07-01 02:22:59

Calliban,

There are five solutions to the problem, as I see it:

1. We start synthesizing hydrocarbon fuels from scratch. This solution only requires capital investment into a massive solar or nuclear thermal generating system. It requires no fundamental changes to business as usual.
2. We use low energy density materials as the basis of a massive low energy density energy generating and storage system. I fancy this solution because it can be completely mechanical, and simple enough for most people to maintain in most places around the world. It lacks the superficial efficiency of electricity, but has its own charm.
3. We go nuts with nuclear power and propulsion. I really like the reliability of nuclear power, but the costs have to come down.
4. We get off this planet so we can find the vast reserves of minerals and metals required to make this green fantasy function at any level worth pursuing. This solution captures my imagination. I would dearly love to see other worlds, even if I die there.
5. We revert back to living the way we did prior to industrialization. This seems to be the way we're headed, to my dismay.

I'm in favor of solutions 1-4, all of which lead to a better future. Solution 5 is insufferably dumb. The solutions I've proposed were based on total cost of ownership. Solutions 1 and 2 were arrived at out of a desire to minimize cost and still provide energy to everyone.

SpaceNut · 2023-07-01 08:07:24

5 rolling the clock back 200 yeas or so is working to live with one's own efforts rather than working to earn a paycheck turning back to a do-it-yourself condition of if you want something you learned how to build it.

Surprisingly this total topic is about being able to do so at an industrial scale or at the personnel level of what one needs to create power for use from as stated above in number 2.

Even with the list of documents in earlier pages for the solar derived thermal energy, I am still looking for those cheap materials to be able to build based on knowledge within them. The saving of heat at a variety of thermal energy levels and media types seems quite easy at first glance with that conversion via exchange to other fluids to make power possible using pumps, turbines to create motion in the system.

As you note in #1 we could create stored in other formats building blocks that can later be turned into other fuel types and so forth. As well as #4 getting off the world to go into space for the activity to mine and make use of it. Both are the dream to be held but there are those that will stand in the way for a number of reasons from childish to just being corrupt.

I am still reading an learning what it will take to create that energy that I need, and it looks very doable.

Update
a bit late..

The homeless are already there. Its being ignored as to why its happening. Not all are by choice.

kbd512 · 2023-07-02 14:28:37

SpaceNut,

Pursuing Solution 5 demonstrates a stunning ignorance of history. All the people who ever lived that way were desperately trying anything to escape the endless cycle of poverty this way of life dictated to them. Hydrocarbon energy was their salvation. Coal, gasoline, and diesel literally ended slavery for people who lived in parts of the world that had these fuels. By about the time of the Civil War here in America, we developed hydrocarbon fuel powered combine-harvesters that eliminated the requirement for human hands to pick cotton. We no longer pick cotton by hand because we can find more profitable and less dangerous things for people to do with their hands in a comfortable seated position, like making cotton clothing from the cotton and fabrics that all those diesel powered machines deliver to us. A single machine that easily fits in a barn and doesn't die when the engine is shut off could perform the work of hundreds to thousands of people or even beasts of burden, like plow horses and water buffalo. There are plenty of countries in Africa, Asia, and the Middle East, where the people are still forced to live pre-industrial lives. You won't find one of them who thinks that's a great way to live, except for the armed cretins who force them to continue that way of life so said cretins can live like war lords or drug cartel leaders while everyone else suffers. They remain poor, largely uneducated, they have high mortality rates, disease and violence are endemic. That way of life only appeals to people who are anti-social in nature, but to no one else.

Yes, this topic is primarily about civilization scale solutions, which primarily involves industrialized nations harnessing low temperature thermal power to do the important work of maintaining our technologically advanced societies, so that we don't regress to Solution 5. I think Solution 2 and 3 hold the most promise, because they don't require materials and technologies that don't exist, and never will exist at the scale required. Solution 2 is easier to build than Solution 3, even though it uses a lot more steel and concrete. Energy abundance from hydrocarbon energy gave us Solution 3, as well as all the photovoltaics and wind turbines and electro-chemical batteries. We did not attain any of those more sophisticated solutions without lots and lots of energy.

Solution 2 is entirely doable, but it requires some shifts in thinking about how we use energy, and why we would want low energy density systems to replace high energy density systems. The best reasons have very little to do with energy source itself, and more to do with ownership and responsibility.

The 3 strongest arguments in favor of Solution 2 are as follows:

1. It can actually be deployed at the scale required to meaningfully reduce hydrocarbon fuel consumption, because the materials and manufacturing capacity exist at the requisite scale to implement it. For people who foolishly believe that coal / oil / gas were anything but humanity's salvation from perpetual endemic poverty / slavery / disease / war / famine, this solution provides a minimally workable avenue / outlet for their Solution 5 proclivities. After the machinery is built, a single person can be largely self-sufficient, because the machinery involved is so simple and understandable, whether you're so poor that you have no formal education, or you're comparatively rich but anti-social. It has a bit of an Amish flair to it, or "steampunk" as Terraformer called it, but the tech itself furnishes a like-kind replacement for gasoline and diesel for the sort of short-range on-demand transportation that generates the most economic activity.

2. The sort of equipment involved creates a sense of permanence for those who are not seeking out novelty or an endless cycle of costly consumption. There are many of us, especially those of us on the political right, who find nothing novel or creative or progressive about planned obsolescence. In point of fact, we despise it. We prefer to be masters of our own technology, to the extent that we can. Those on the political left have developed contempt for the hydrocarbon-fueled machinery of society and commerce that makes their city lives possible. If you cannot repair and maintain your own machines, then you're not the master of your own technology- your technology has instead mastered you. You're functionally no different than a slave, totally beholden to the whims of your master. The right doesn't want more computerized gadgets that have to be replaced every few years or so. This is a compromise solution. The left gets something it wants, in return for something that the right wants, which is not to be enslaved to expensive disposable computers that almost nobody, left or right, actually factually understands and can repair.

3. This sort of technology embodied in Solutions 2 and 3 gives a great number of people something to do with their own two hands. Through their hard work and responsibility for the machinery that powers society, they develop a sense of purpose which is largely lacking amongst the rudderless western youth who have been indoctrinated to believe absurd things that are ultimately self-destructive and without merit. When I was a young man, I knew that I was interested in and passionate about building and maintaining radios and computers. It's an endless source of fascination for me, personally, a series of complex logic puzzles to be solved, but few people maintain my level of interest over their entire lives. Other young men wish to use their hands and skill to make physical things. If there is no place for those men in society, then there is no society. Toilets, washers and dryers, flash evaporators, heating and air conditioning systems, power plants, and motor vehicles don't need to be burdened by computers. Since none of the promised energy consumption reduction benefits touted by computerization have ever materialized, they've run their course for these sorts of use cases and have ceased to provide utility for their intended purposes.

I'm not simply after a material / energy / economics solution. I'm after a social / political solution as well. I'm operating under the assumption that most people, regardless of other personal beliefs, still want to live in technologically advanced societies. The preponderance of evidence all points to the truth of that assumption. If that assumption is valid, then we need a compromise solution that has broad appeal across ideological differences. The political left think they can force other people to adopt or adapt to their ideology-based solutions, all of which are divorced from material / energy / economics realities. Electricity is an object of fascination and affection for the political left, because it's "magical" to them. Like most people, they have no understanding of how the things they want are actually made and delivered to them. It's okay to not care (the "I want what I want" attitude), but it's not okay to both not care and demand all other people mindlessly fixate on something that the left refuses to understand and appreciate. They seem to believe that they can force both technologies and the mass adoption of technologies into existence, using the power of law. This belief has limits, though. Forcing people to travel by rocket when there are few to no rockets to be had, for example, and certainly no practical way for everyone to use rockets to go to a grocery store, is both asinine and self-defeating. They're slowly but surely discovering the limits to ideology, as it pertains to energy and environment.

The left assert that they want people to "just quit burning oil". That's about as practical a thing to accomplish as "just quit eating" or "just quit breathing". It only shows how ignorant they are about energy, both where it comes from and how its made. Hydrocarbon fuels, not wind, not solar, not even nuclear power, gave the majority of the people on this planet the standard of living they enjoy today. All whining about the after-effects of burning fuels aside, most people are not going to live the way the Amish do. The political left spares no effort to mock and deride those people for living simple lives and foregoing the trappings of modernity. They view them as backwards. That means many on the left don't even believe their own ideological assertions about energy. It's the "other guy's problem". They think they're going to regulate our ability to use energy out of existence, by pricing the poor people out of the energy market. That's pretty evil, even if you pray to the Sun god or electricity god. This insanity is repeated like religious dogma, but never adhered to by the people who concocted it. Funny that.

We created a society, a way of life, and an economic model centered around energy abundance, nearly all of which was provided by burning hydrocarbon fuels. That process took about 200 years to arrive at where we are today. The notion that we will "just up and change" every aspect of society over the next 20 years, is ludicrous. None of the left's proposed alternatives are remotely practical or affordable at the scale required. An electric car that's double to triple the price of gasoline powered equivalent is why only wealthy coastie yuppies have bought them. Almost nobody else can afford to. As the price of input energy and materials goes up because we're not looking for new sources of oil, those prices are unlikely to ever come down substantially. Even if we could make enough battery powered cars, which we can't, we would theoretically reduce hydrocarbon energy consumption by a whopping 8%. It takes 100 barrels of oil to create Lithium-ion batteries that store the electrical energy equivalent of 1 barrel of oil. Are electric cars 100X more energy efficient than gasoline cars? That's what it would take to actually reduce hydrocarbon energy consumption while making all these electric cars, and then you have to recycle them 10 years later, while still maintaining that efficiency increase. Otherwise, all you did was dump even more hydrocarbon energy into your manufacturing system than what we're presently using. Wow! What an accomplishment!

The way you get more people to adopt a new technology is to make it cheaper to own and operate, not more expensive. That's what my proposals do. They give the political left the big government spending they crave so much, this time with the end result of actually building something that produces the energy we need. Americans need to fund another Solyndra startup like the leftists need to do more drugs. The end result will be a drastic reduction in the demand for so much coal / gasoline / diesel. This is mostly because it lasts so much longer than 10 to 25 years. Beyond that, these proposed machines give the political right affordable transport and appliances that doesn't require a clean room to work on. They can be repaired using hand tools and elbow grease. That's the appeal of old cars and other mechanical machines to those of us on the political right. They can be repaired and maintained with a little bit of hard work. When a microchip-based computer or photovoltaic panel or battery burns out, there is no "clean it up / replace the seals / start it back up again". If the big ideas people on the political left invent a repairable microchip or battery, then we'll talk about the wonders of electrification and computerization. Until then, I've had enough of their all-electric nonsense.

This entire electrification craze runs afoul basic physical material resource limitations that no amount of legislation is ever going to change. All of these non-solutions related to electricity and efficiency require more and more energy, all of it coming from hydrocarbon fuels, and rapidly depleting specialty metals stocks that we're not going to get more of. So, if there is a future "beyond oil", then it's also "beyond electricity" as well, since most electricity comes from burning coal / oil / gas. Short of fusion reactors, matter / anti-matter reactors, or something similarly advanced, there is no "beyond 39.75kWh/gallon".

From a CompositesWorld Article by Brian Bishop of TCR Composites:

Years ago, as a carbon fiber salesperson, I sat in a room filled with automotive executives negotiating the price of carbon fiber. Their sole focus was to justify why a $5-per-pound carbon fiber price would place the material in such high demand from the automotive industry that it would exhaust the world supply.
The automotive executives were so focused on carbon fiber price — in their minds, the largest raw material input — that they ignored the largest cost component that would ultimately determine whether using this material was viable: efficiency.
During that meeting, I stated something ironic: Even if carbon fiber were free, it was still unlikely that auto producers could afford it. Then I explained that metal-stamped hoods required seconds to manufacture, while molding carbon fiber hoods took, at best, minutes. With a bottleneck like that, it would be difficult to meet automotive production targets. To this day, that company has not used one single pound of carbon fiber for automotive body panels. In the meantime, the inflation-adjusted price of carbon fiber has fallen well below that $5 per pound threshhold.

The moral of the story is that time has meaning. Electrical engineers have devoted the sort of "Moon Shot" / "Manhattan Project" level of effort to electronics and batteries that GW suggested we undertake, for pretty much my entire lifetime.

What are the results?

Nothing remotely approaching the improvement required to actually replace coal / oil / gas. What we're doing right now is equivalent to a Chinese Fire Drill conducted by people driven by ideological dogma. They stubbornly refuse to acknowledge that the physics and material resource limitations of what they wish to do is not amenable to their dogma. No technically feasible solutions to replace oil are being pursued at the present time. That's the real reason oil hasn't been replaced. Everyone who is intellectually honest knows it. We have enough brain power, horsepower, muscle power, and available technology to devise multiple alternatives that could work. None of those feasible alternatives do anyone any good if we refuse to pursue them. Making more electronics and batteries is equivalent to burning more and more oil for ever-diminishing returns. If there's ever a broad general understanding of what's actually happening, a lot of people are going to be very angry when no part of what they've been promised is delivered to them. Right now a lot of well-intentioned people are operating under the false premise that those in power and those in engineering are working to deliver a better future. Those of us here already know why what we're pursuing, this "all-electric future" pipe dream, will not work.

SpaceNut · 2023-07-02 18:08:04

The issue is how to create energy without the carbon content even at a reduced level is better than the continuing growth of a world to hot and arid too. The level of fuel generating just "39.75kWh/gallon" is the costly part. I do agree with you kbd512, that turning the clock back is a huge mistake and issue for mankind but it's sort of seem that we are doing just that by making energy so costly.
Currently scale of energy creation is working against us as they continue to raise the rates that we pay.

So far, we have no cheap solutions to have a gallon to use every hour that we need. We also cannot afford its cost at this ever-rising amount that we are paying at the pump.

If we are limited to what we can earn, then we are all doomed since we cannot keep increasing wages to offset costs.

An AC unit that is 5,000 BTU 1.5 kwhr which is sort of average, though we do not use it constantly all the time. So, if we can generate twice that we are back in business when suppling our homes use.

kbd512 · 2023-07-02 20:52:18

SpaceNut,

The world will not become "too hot and arid". On a planet largely covered with water, that's not what happens when it gets a few degrees hotter. We already have historical precedent backing up that assertion. Atmospheric CO2 levels were at 1,000ppm when scientists asserted that Earth had its greatest biodiversity at any point in time, before or since. There was little to no ice at that time. Given that there was no shortage of life on Earth when atmospheric CO2 was at or above 1,000ppm, and we lack the hydrocarbon resources to raise the atmospheric CO2 level beyond 1,000ppm, I'm not overly concerned with whether or not humanity and most of the other species will thrive. History says the Earth doesn't cease to be inhabitable, even if 100% of the ice at the poles melted tomorrow.

I already told you why we have no solutions. Scientists have been tinkering with photovoltaics and wind turbines and Lithium-ion batteries for the past 50 years.

After the first 30 years or so, why was it not apparent that there wasn't enough Lithium or Copper on planet Earth, to replace some significant fraction of the power provided by heat engines?

The regressive left pissed away the opportunity to transition to nuclear power, in favor of burning more coal and gas. Then they pissed away the opportunity to transition to solar thermal power by blowing all our remaining money on hydrocarbon fuels and photovoltaics and wind turbines and batteries.

Shall I now believe that they've learned any lessons?

We both know the answer to that question. They're still participating in the world's largest Chinese Fire Drill. They don't learn, they just bash their heads into the brick wall of thermodynamics and energy until they render themselves comatose. They're still whining about what they can't have, rather than implementing achievable solutions. We still have people on this forum posting about electric flying cars for Wall Street bankers, as if that's really what the world needs at this juncture.

You guys can spend every last cent we have on this insanity to create novel new ways for rich people to kill themselves through their own ineptitude, but at the end of the day the rest of us, which also happens to include the majority of you leftists, are going to be without energy and without anything that resembles the civilized society and prosperity we previously enjoyed as a direct result of hydrocarbon fuels.

SpaceNut · 2023-07-03 11:02:21

https://yaleclimateconnections.org/2019 … te-change/

https://earth.org/data_visualization/a- … ry-of-co2/

https://en.wikipedia.org/wiki/Carbon_di … atmosphere

kbd512 · 2023-07-03 12:57:55

SpaceNut,

This is where climate change dogma fails. There is no plant or animal life on Earth without CO2. Period. That is hard scientific fact, every bit as Iron-clad as the second law of thermodynamics.

All that CO2 pulled out of the atmosphere over tens of millions of years was / is / ever shall be the very basis of life itself, here on Earth. Every species we know of is a Carbon-based form of life. Before humanity came along, the atmospheric CO2 levels continued to steadily decline, almost to the point of starving all plant life during the last Ice Age. Somewhere between 100ppm and 150ppm, life ceases to exist, because plants don't survive without at least that much CO2. We bought ourselves and most of the rest of the species more tens of millions of years by bumping it back up to 450ppm. Earth will have to wait for another day to become a lifeless snowball.

Far more species have died off entirely than presently exist now, many long before humans existed, regardless of what those species did or didn't do to survive. Nothing about life is ever permanent. Running ourselves out of energy is a surefire way to end it. We're basically ants in the grand cosmic scheme of things. If we want to live here as long as possible, then we require energy to do that. The only fate we're guaranteed to share is the one we decide for ourselves.

This energy issue is a solvable problem when dogmatic ideology is removed from the decision making process, but the piper will be paid, one way or another. We might want to focus on the problems that will kill us all first. The #1 problem facing us today is energy and resource depletion and the endemic poverty related to lack of energy and materials. That's probably the issue to address first. We can worry about the temperature changing one way or another after we've solved our most pressing problem. Earth becoming a few degrees warmer is not even close to the greatest threat to humanity. Remember that virus that wiped out so many of us? Imagine what humanity would look like today if it had a 50% mortality rate. If life was truly so fragile, then the temperature changes of each passing day would be tantamount to a death sentence, yet nothing of the sort ordinarily happens. To a point, life is pretty robust.

If a giant asteroid ever happens to cross paths with Earth, then all the obsessive hand-wringing over climate change will have been an utterly pointless waste of time and energy trying to solve one problem that was preempted by a wildly more catastrophic problem. That's why you solve the problems that will kill the most people first, and then worry about every other potential problem. This single-minded focus on Earth's temperature changing by fractions of a degree over decades has sucked all the Oxygen out of the room. Everyone in the room is slowly suffocating as a result.

SpaceNut · 2023-07-03 18:46:00

The potential for energy is just a simple state of a higher than another lower for any form we choose, with the value being a greater delta means we have more of it to create from.
This simple condition creates motion for our current system of heat and pressure. That motion is mechanical and is converted to electrical for all to use since mechanical is a direct connection.

Calliban · 2023-07-05 13:59:14

Compressed air energy storage calculator.
https://tribology-abc.com/abc/thermodynamics.htm

I raise this here, because air compression generates a great deal of heat. We could use this heat for other applications, or we could store it in a vehicle as hot water or hot rock, along with a compressed air tank and use it to preheat air before expansion. If air is preheated to 300°C before going into the first stage of an expander and then reheated, then each unit of air will generate twice as much energy.

tahanson43206 · 2023-07-05 14:08:12

For Calliban re #138

This observation is about your opening line in the post: "generates a lot of heat"

The space programs around the world are ordering a lot of liquid air, and SpaceX is ordering a lot of liquid hydrocarbon fuel.

I bring this up in the context of your post, because (this is just a guess in my part) I'll bet that none of all the heat produced by the compression needed to produce those propellants is saved for later use. I'll bet it ** all ** goes to waste via water or dump to the atmosphere.

There might be an opportunity there.

(th)

SpaceNut · 2023-07-05 18:38:06

I am well aware of the compression into a tank generating heat and the higher that pressure is the more heat it creates.
I worked at a place that compressed 5000 psi into a composite scuba like tank that when shot it would not implode but just would vent.

We are still at the thermal barrier and control of it problem where to low we get next to nothing from the source and to hot we introduce other problems into the system.

post 66 contains the documents indicate that at 100'c and under tends to be of no value other than for hot water. Whereas we increase up to 350'C we seem to still only achieve a25% efficiency of conversion to energy.

Calliban · 2024-02-23 04:57:25

SpaceNut recently linked to an article about a company that is developing thermal energy storage using graphite blocks. Limestone will be much cheaper, but cannot store heat at such high temperatures. At high temperatures, calcium carbonate decomposes into calcium oxide and CO2.
https://en.m.wikipedia.org/wiki/Calcium_carbonate

However, this chemical transition can be halted by maintaining a vapour pressure of CO2 above the limestone surface. At 1000°C, a CO2 pressure of 40bar(g) is needed. The interesting thing is that this CO2 cover gas could also be used for heat extraction from the limestone. Heat addition could take place using induction coils heating embedded iron, or heating elements within tubes in the limestone thermal mass. The CO2 cover gas could be blown through heat exchangers, which either raise steam for power generation or convey heat to direct heat applications. There are plenty of direct heat applications for high heat. Industrial heat accounts for one fifth of global energy use.

Limestone is a suitable thermal storage material for temperatures up to about 1000°C. At 898°C, CO2 vapour pressure is 1atm(a). So for temperatures up to this limit, a pressure vessel is not needed. Limestone could store the heat needed for calcining in the cement production process. The sintering of clinker takes place at 1450°C, which is too hot for limestone to be practical as a thermal storage material. Silica or graphite could store heat in this temperature range.

Last edited by Calliban (2024-02-23 05:11:30)

SpaceNut · 2024-03-13 17:01:25

A Tiny Town Is Betting on a Sand Battery to Heat Homes. It Could Revolutionize Energy.

A 1-megawatt sand battery that can store up to 100 megawatt hours of thermal energy will be 10 times larger than a prototype already in use.
The new sand battery will eliminate the need for oil-based energy consumption for the entire town of town of Pornainen, Finland.
Sand gets charged with clean electricity and stored for use within a local grid.
That first installation in western Finland features an insulated silo made of a 23-foot-tall steel housing and filled with 110 tons of sand and heat transfer pipes. Electricity from the grid or local production allows the company to charge the sand when clean electricity is more cheaply available, typically during the middle of the night. The electrical energy is transferred to the heat storage using a closed loop air-pipe arrangement.
The sand battery will arrive ready for use, about 42 feet tall and 49 feet wide. The new project’s thermal storage medium is largely comprised of soapstone, a byproduct of Tulikivi’s production of heat-retaining fireplaces. It should take about 13 months to get the new project online, but once it’s up and running, the Pornainen battery will provide thermal energy storage capacity capable of meeting almost one month of summer heat demand and one week of winter heat demand without recharging.

Calliban · 2024-08-28 06:45:15

I wonder if this topic can provide a solution to the offgrid solar power storage problem. If the house has enough outside space, maybe a heat battery coupled to a small steam or S-CO2 based electrical generator? The battery would be charged by resistance heaters powered by direct current from PV panels. The power recovery would produce AC at 110v and hotwater for washwater. With an S-CO2 system operating from 400 - 500°C, about one third of the original DC could be recovered as AC electric power. The other two-thirds will be low grade heat.

If a small steam turbine is used instead, then a quarter of the charging energy will be recovered as AC at most. But the system is likely easier to build. If electricity would otherwise be used to heat washwater, then power recovery efficiency is less important, as the wasteheat from the engine is still available for washwater heating. Maybe a vehicle could be run this way as well. So long as the waste heat isn't 'wasted'.

Last edited by Calliban (2024-08-28 07:02:10)

tahanson43206 · 2024-08-28 08:15:03

For Calliban re #143

Thanks for renewing this topic in the direction of practical demonstration of these ideas. And thanks to SpaceNut for posting the report of actual implementation of the idea in Finland.

I went back and read the first set of posts on the first page... in the heady early days, there seemed to be momentum building toward an actual demonstration of the ideas in discussion, but nothing appears to have happened, except for the Finland project.

I do have a technical question that might fit into the theoretical discussion .... Is there an optimum mix of storage material and heat exchange material.

Calliban described holes in limestone as likely to be more efficient for thermal energy transfer to a working fluid, than powdered limestone. I am guessing the improved thermal conductivity is related to the tight packing of the limestone by massive natural forces working over thousands or millions of years.

Is there an optimum material choice for pipes to pass through the limestone?

Is there an optimum material choice for the transport of thermal energy from the store to the power-takeoff-device?

Calliban reminded readers that some materials that might be considered have upper limits of temperature they can reliably handle.

I get the impression that even such a simple sounding system as a thermal energy store offers challenges to the designer that would give pause to the faint of heart.

(th)

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#126 2023-06-27 13:01:44

Re: Limestone-based Thermal Battery

#127 2023-06-27 19:44:13

Re: Limestone-based Thermal Battery

#128 2023-06-29 23:09:49

Re: Limestone-based Thermal Battery

#129 2023-06-30 09:31:47

Re: Limestone-based Thermal Battery

#130 2023-07-01 02:22:59

Re: Limestone-based Thermal Battery

#131 2023-07-01 08:07:24

Re: Limestone-based Thermal Battery

#132 2023-07-02 14:28:37

Re: Limestone-based Thermal Battery

#133 2023-07-02 18:08:04

Re: Limestone-based Thermal Battery

#134 2023-07-02 20:52:18

Re: Limestone-based Thermal Battery

#135 2023-07-03 11:02:21

Re: Limestone-based Thermal Battery

#136 2023-07-03 12:57:55

Re: Limestone-based Thermal Battery

#137 2023-07-03 18:46:00

Re: Limestone-based Thermal Battery

#138 2023-07-05 13:59:14

Re: Limestone-based Thermal Battery

#139 2023-07-05 14:08:12

Re: Limestone-based Thermal Battery

#140 2023-07-05 18:38:06

Re: Limestone-based Thermal Battery

#141 2024-02-23 04:57:25

Re: Limestone-based Thermal Battery

#142 2024-03-13 17:01:25

Re: Limestone-based Thermal Battery

#143 2024-08-28 06:45:15

Re: Limestone-based Thermal Battery

#144 2024-08-28 08:15:03

Re: Limestone-based Thermal Battery

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