Permenance Movement

Calliban · 2023-03-17 04:57:19

In a nut shell, this is a movement that seeks to build things that last.

From my investigations into renewable energy, I have come to realise the wisdom of building things to last. We can make lofty claims about recycling, but the bottom line is that dismantling something and recycling it is unnecesarily energy intensive. It involves more labour than is neccesary. More transportation than neccesary. Even steel, which is widely recycled, must be be heated to melting point and cast into new components. Far better simply to make something that doesn't wear out. Like those 17th century Dutch windmills and Victorian railway bridges. It would make sense to apply some Victorian engineering to a project like an aerial tramway. Brick or stone towers that absorb forces compressively, cast iron pylon arms that resist wear, fatigue and corrosion, hydraulic lifts with components that don't wear out. Our fossil fuel supplies are gradually diminishing. When we build, we should be building to last forever, or at least as long as reasonably practicable. The cables, motors and bearings will require periodic replacement. There is no avoiding that because they are moving parts. But the towers and support pylons can be built in a way that allows extreme longevity.

This should become a cultural movement across the western world, I think. When your energy budget is gradually shrinking, it makes more sense to build for permenance and long-term reusability. It should apply to everything we use. Instead of putting food into tins and packets, we should be putting it in standardised glass jars that get reused over and over again. We should be building vehicles that last 100 years, with modular components that can be replaced when wear or corrosion makes them unusable. Our appliances should be built in the same way. They should be designed for long life and repairability. Our buildings should be compressive masonry structures designed to last for centuries and designed to be beautiful, as befits permanent structures. For anyone that cares about environmentalism, such a movement is far more practical and productive than the increasingly vacuous and perverse Green Movement. I propose the 'Permenence Movement'. For the purpose of forward discussion, an 'item' is the word I will use to describe any tool, appliance, machine, vehicle or structure, that has utility to human beings.

How do we make 'items' that last forever? By forever, I essentially mean a timeframe that is long compared to an average human lifetime. This could be anywhere between 100 and 1000 years, depending upon the nature of the item. We need to think about the sort of assaults that an item will face over its lifetime. By this I mean repeated stresses (bending, shearing and compressive); accidental damage due to drops, impacts, heating, etc. Abrasion for parts that come into contact. Weathering - hot and cold cycles, exposure to damp, the wind, acidic rain, etc. We need to make items that either resist all of these things for the duration of their lives, or have components that can easily be replaced and swapped out without too much energy and labour cost.

We see some examples of the Permenance Thinking already in society, although increasingly modern society has turned away from it. But in the nuclear sector, light water reactors are being designed to last 80 years, thanks to good water chemistry control, new oxidation and radiation resistant alloys and control of thermal stresses. This is happening because nuclear powerplants are expensive to build and decommission, but cheap to operate. It would make sense building a plant that operates for a century or more if we can. If that can be done, then the capital cost of building is spread over a whole century of operation, rather than just 40 years. So return on capital investment is 2.5x greater.

Last edited by Calliban (2023-03-17 08:29:48)

Terraformer · 2023-03-17 05:25:06

See also: Permafacture.

I like the name Permanence. Reminds me of the space opera by Karl Schroeder. Measure your plans in centuries. Still annoyed at the generations before me for not bequething great wealth.

Like the false dichotomy that gets set up between economic growth and lowering the cost of living (the things we'd need to do in either case are mostly the same, like build housing and railways), there's a false dichotomy set up between settling space and living sustainably on Terra. If we can't make the latter work we're not going to make it out there, in a far less forgiving environment. Screw up agriculture down here and you might lose a 1/3rd of your population to starvation; screw it up out there and everyone may asphyxiate. One thing we can be sure about any interstellar civilisation is that they're capable of long term thought, because anyone who isn't won't make it that far.

This is one of the great, unnoticed, divides in politics. Closely connected to those who appreciate logistics and infrastructure and those who don't. Largely cuts across more well known divides, unfortunately mostly in the sense that both left and right, and centre too, aren't that good at getting their heads around concepts like limits and numbers (I am pretty sure at this point that Boris Johnson has dyscalculia -- there's no record of him ever being capable of maths, even at school). Libertarians are little better. I guess those burdens can be dumped on Martha's sons...

Calliban · 2023-03-17 05:26:26

There are lots of reasons why permanance should become a deeply engrained value in everything we do. But there are two overwhelming reasons that have to do with our collective predicament.

1. We are using resources of all kinds at an unsustainable rate. This includes minerals, fossil energy, water, biomaterials like wood. The environmental impact is growing and remaining reserves are diminishing as we operate a dissipative landfill economy.

2. Demographic decline in most industrialised countries is undermining both consumer demand, capital base and worker bases, simultaneously. This means we are going to lose the benefits of mass production in most of the world. Building anything will become more difficult and expensive. One way of managing that problem is to use labour, energy and materials to build things that last for a very long time. You will still need to manufacture some of those items, but for the most part we just reuse our stock of items over and over again. Most of what we buy will be bought second hand, or even third, fourth, fifth, 'ad finitum' hand.

Our manufacturing base will be smaller and more time and labour will be given over to maintaining and repairing.

This philosophy becomes increasingly important if we must make a transition to running society off of ambient 'renewable' energy. Ambient energy is low in power density and is intermittent in nature. This second problem reduces energy density even further, because we must either store energy for when it is needed, or only use energy when it is available, which means poorer utility of capital equipment. The lower power density means that a great deal of embodied energy is needed for each unit of useful power generated by the machine. The problem is particularly accute for Solar PV, with panels not even returning their own embodied energy costsover a projected 20 year life, if built in high lattitude and low insolation countries. But the problem is less acute if the equipment involved has a long lifespan. Wind turbine EROI is <10 on average, if the turbines have fatigue life of 20 years and pumped storage is used for buffering. But if the major components of turbines lasted for 200 years, with only minor components requiring replacement, then EROI will be much higher, edging towards 100 over it's lifespan.

This is the philosophy that must be embraced for renewable energy to make any sense at all, even in the short term. It just isn't energetically sustainable unless the systems harvesting it are built to last. But permanance applies to everything that we do. If it costs more to make or buy an item, then maintaining a good living standard requires that the item lasts longer. A car that costs twice as much to buy is a much better investment if you know it can be easily repaired and made to last a lifetime. Even better if you can pass it on to your children and grandchildren. We get value out of an item every time it is used. The total value is proportional to how long it lasts.

Last edited by Calliban (2023-03-17 05:46:26)

tahanson43206 · 2023-03-17 05:57:13

For Calliban re new topic ....

Best wishes for success with this promising new topic .... While you appear to be opening with a focus on Earth, it seems to me the philosophy translates easily and naturally to Mars or any off-Earth location.

SearchTerm:Permanence of architecture and design of machinery or systems

Update 2024/10/01 https://newmars.com/forums/viewtopic.ph … 81#p226881

In the post at the link above Calliban has shown a detailed plan for a thermal energy system for a town in Britain.

(th)

Calliban · 2023-03-17 07:28:41

Thanks, TH. Problems with Permanence:

1. Technical obsolescence. That's a really well made coal plant from the 1920s, but now we have nuclear reactors.
2. Return windows. When humans buy things, they care about the near term more than the long term. An item that performs an identical function, costs half the price, but lasts ten years rather than fifty, will be more desirable to people that are short of money and need to meet an immiediate need. Likewise, a manufacturer often doesn't care how well made his products are, provided he can keep selling them.

These are barriers to the application of Permenance.

There are some things for which permenance isn't applicable. Bullets can be designed to last longer in storage. Maybe shell casings could be reused, but it ofren isn't practical to collect them in battle. Projectiles are never reusable because they deform on impact. Food is an expendable commodity. Permenance applies to the way we grow it. We should eat a diet that aims towards longevity. But food itself can only be eaten once. For things like packaging, repurposing may be more practical than reuse. No one wants to reuse a chocolate wrapper. But if we make the wrapper out of a low cost paper, made from a crop residue or recycled wood, then we can burn it for heat and return the ash to the soil.

Last edited by Calliban (2023-03-17 07:42:32)

Calliban · 2023-03-17 07:31:08

How to make you car last forever.
https://www.wellrigged.com/how-to-make- … t-forever/

More to the point, how do we design a car that can last forever? Things wear out. So the key to long life is making the car easy to maintain. Simplicity is surely key to that.

How long can a nuclear plant run? Regulators consider 100 years.
https://www.utilitydive.com/news/how-lo … rs/597294/

This is due to improvements to alloy composition and water chemistry control. UK gas cooled nuclear reactors are an expensive failure, precisely because they were built with graphite moderators that rapidly degraded in hot CO2 coolant and couldn't be replaced. This does not neccesarily mean that gas cooled reactors are a bad idea. The UK made design choices that limited the life of its reactors. A pebble bed design that replaces moderator or a pressure tube design that cools moderator using something non-oxidising, coukd have allowed GCRs with very long life expectancy.

Reusable packaging.
https://en.m.wikipedia.org/wiki/Reusable_packaging

Sustainable packaging.
https://en.m.wikipedia.org/wiki/Sustainable_packaging

Three tipes to manufacturing products that last a lifetime.
https://www.entrepreneur.com/growing-a- … ime/290935

The rise of short-lived building.
https://www.architectsjournal.co.uk/new … -architect

The prevailing trend in building is the opposite of permenance.

Last edited by Calliban (2023-03-17 07:53:39)

Terraformer · 2023-03-17 07:53:16

An item that performs an identical function, costs half the price, but lasts ten years rather than fifty, will be more desirable to people that are short of money and need to meet an immiediate need.

The same applies to the politics of infrastructure. No-one gets rewarded for what they did forty years ago. I am not joking when I say we need to have something like the Crown Estate build and maintain infrastructure. If it needs to be replaced in twenty years, the reigning monarch will take a big hit to the pocket now that the civil list system has been done away with. Of course, the steward/owner/manager of the infrastructural estate doesn't *have* to have an official position. Look at John Whittaker, of the Peel Group. Manchester Airport and Ship Canal are going strong.

Calliban · 2023-03-17 08:20:01

Terraformer, that is an interesting idea. I think one of the arguments in favour of hereditary peerages, is that if your position is something you hand down to your children, you have a vested interest in making sure the country is well run and a long term view is taken. The consequences of failure will follow you to your grave. And your children will curse you in your grave for the mess you create them. Labour abolished hereditary peerages on the grounds of 'social justice'. Most of the people they put in the House of Lords are absolute cads, men like Lord 'Sugar' and Lord Levy. Not their real names of course. These men achieved their riches by exploiting everything around them. And achieved their power by financing political bad actors who vandalised the country. But I digress.

I think permenance needs to become a deeply engrained cultural value. Something that is drummed into people from a young age. Build things to last forever. Buy things that you can hand down to your grand children. We tend to value old things as antiques in ways that newer items are not valued. With buildings, longevity and maintainability need to be important considerations for planning permission. Nothing that lasts less than a century deserves to get built. Here are some of the world's oldest buildings still in use.
https://www.grunge.com/327172/the-oldes … use-today/

Last edited by Calliban (2023-03-17 08:26:32)

kbd512 · 2023-03-17 12:05:04

Calliban,

1. The basic technology of steam kettles hasn't changed since steam kettles were invented. The only real technological innovations are steam kettles that don't require fires- nuclear (these have existed for 70 years) and solar (these have existed for over 100 years) steam kettles.

Apart from that, a steam kettle is a steam kettle is a steam kettle. The figures of merit are how much boiling water can it hold, and what does it cost to make one that can last for a human lifetime, because we would like to move on to expending labor and energy on things other than making steam kettles, the moment we can make a good steam kettle. A set of silverware or kitchen knives is a substantially similar proposition. Ditto for other appliances required to prepare food, all of which can and should be fundamentally simple and durable devices. A food service may benefit from Copper or Aluminum cookware, as well as stainless steel for certain applications like large serving pans. A person or family is still best served by old-fashioned cast Iron.

Since almost none of us will last more than a month or two without eating, and a home-cooked meal is an indicator of a high-functioning society and its bedrock- the nuclear family, the answers to such questions are non-trivial as far as outcomes are concerned. Every other aspect of a high-functioning society with advanced technology starts with a mother's ability to feed herself and her children, and the father's ability to provide for his family.

2. This situation of short-term gain over long-term gain is entirely a function of business ethics, or lack thereof. This is only a problem in a world where poor quality is actively encouraged back a lack of ethics. A durable steam kettle actually costs less than a poor quality steam kettle. The same applies to other appliances and cars. The benefit of a durable good is realized over time, which presupposes its purchaser understand the value of time. No part of education is teaching ethics or culture to young people in such a way that they begin to value their own time. The educators are fixated on painting a caricature of the world predicated on the "never-ending now".

A high quality car is actually cheaper to make and own than a low quality car, but we have duped people into thinking that "whiz-bangery" and "sex-appeal", whatever that means to them, is somehow more preferable than having an affordable and functional means of transport that is durable and long-term sustainable (need not be replaced every few years). Well, a car is a personal transport device above all other considerations. That's what it was meant to do. Its purpose is not to befuddle its owner or mechanic with byzantine complexity, nor does a good car have much of anything to do with sex. A woman who will sleep with you, based upon what car you drive, is probably not someone you're going to raise a family with as a life partner. If something that petty matters greatly to her, then her valuation system is completely screwed up and you're going to have a very rough go of it so long as you're with her. The juice is not worth the squeeze, to use another kitchen and food-based analogy. The nuclear family and high-functioning, technologically advanced society requires two stable and reasonably mature adults, with a modicum of actual education in place of feckless ideologies, for any long-term chance of success in life. This starts with a value system which recognizes what is important in life, and what is not.

Having a fancier model of car or steam kettle is not important. Having a reliable means of transport and cooking food, to get work done and take care of the children, is very important. We need to take human society back to first principles. First principles is how we arrived at where we're at today.

All of these ethical problems, which are not technology problems, tie directly to values and culture.

As far as making a car last forever:

1. The car chassis / body must be made from corrosion-protected steel or plastic. Steel has the lowest energy cost but greatest weight. Aluminum cannot be made long-term durable for any reasonable energy cost because it suffers from fatigue cracking typical of most non-ferrous metals which are repeatedly flexed back-and-forth, ultimately destroying the structure over time. However, Aluminum is by far the easiest material to recycle.

Wind turbine blades made from virgin Aluminum ended up costing 5X more than CFRP or GFRP and have the worst emissions by a lot, which is why Aluminum is not used. Bamboo turned out to be the cheapest material by a considerable amount, but it's heavier than CFRP for a given tensile strength and stiffness to prevent blade flex. Flex (not smacking into the tower) is what drove adding weight to the bamboo blades, which were slightly stronger than GFRP and removed about 1t of weight per blade, but about 4X the weight of CFRP at 86m long. That said, you could buy about 4.5 wind bamboo wind turbine blades for the energy and emissions cost of a single CFRP blade, and about 3 per GFRP blade. Bamboo was the least sensitive to blade length in terms of energy / emissions / monetary cost- almost a flat and near-zero line out to the 100 meter lengths studied. Only CFRP, GFRP, 2024 / 6061 / 7075 Aluminum, and bamboo were included in the research, so no idea about steel or hemp / flax / jute. Cotton would be unsuitable due to fiber length. Wood was considered unsuitable due to cost and strength as length increased. Most of the study focused on 86 meter length wind turbine blades (longer than the wingspan of an Airbus A380 by about 6 meters).

For cars, this means interior pieces like the dashboard, steering wheel, and trim pieces could be made from bamboo rather than plastic and rubber. Bamboo has superb vibration dampening qualities. For a lightweight chassis, if we insist on continuing the practice of planned obsolescence, bamboo would not be much heavier than CFRP as a function of length (adequate stiffness would be achievable through other means in a very short vehicle chassis), but would not feel like sitting inside a snare drum, absent the addition of sound / vibration deadening material to the chassis of the technical composites of metal chassis.

2. Wear components, seals / bearings / tires / brakes, have to be routinely replaced. These components will not last forever by the very nature of how they're used. Apart from tires and brakes, they represent a vanishingly small energy investment to make new ones, so the great object of a well-designed car should be to make the process of replacing them simple and fast, as well as requiring few specialized tools.

Sandy Munro, an automotive engineer here in the US with some following, thinks religious removal of all mechanical fasteners is how you improve cost and reliability. There's a kernel of truth in his quest to make things as simple and rapidly as possible, especially as it relates to cost. Once you go beyond a certain point, your solution is not realistically maintainable. If you weld the battery pack into the chassis of an EV, then it's not economically repairable if something goes wrong in the battery pack. It starts to look like another disposable appliance that may cost a little less to make and therefore purchase than a more maintainable one, but it's ultimately a pointless endeavor.

German auto makers have proven that they can make a car which is not maintainable for any reasonable cost, and that the end result costs the consumer inordinately more money, especially in the long run. The reliability of the modern ones are consistently ranked lower than most American and Japanese cars.

3. The car cannot use computer control over any component that does not absolutely require it. Software complexity is real complexity. Maybe you can fix faulty software or computer technology without damaging or replacing anything, but relying on this is a very dubious assumption. A plastic door handle is not an appropriate component to computerize and motorize. That is beyond silly. It has a great "wow factor", but lousy cost and complexity increase for little to no benefit to the consumer or the environment. A backup camera can be very useful for preventing needless accidents. Equipping the car with more sensors and computing power than a fighter jet for "autonomous driving" is another inappropriate use of computer technology. Cars are not fighter jets. You're driving to work, not trying to fly under enemy radar to drop bombs.

4. The use inappropriate engine power, safety equipment, and emissions controls also has an enormous effect on cost and maintainability.

Going much beyond a catalytic converter is fairly pointless for internal combustion engines. For diesels, all of the added emissions equipment seems to do a great job of reducing fuel economy, and given the sheer quantity of diesel burned, reduced range becomes the emission driver. Getting rid of Sulfur in diesel has actually improved engine longevity, same as removing Lead from gasoline, which fouled spark plugs and valves to no end. Detergent oils have greatly improve engine life. EFI has fuel economy improvements, but no power improvement at all over a carbureter, and all spark-ignited engines are most efficient at WOT, which means reducing engine displacement and running at or near WOT at all times is how you improve fuel economy for gasoline engines. Batteries made with Lithium are pointless at a global scale because there's nowhere near enough Lithium. Sodium is more accessible, but every bit as energy-intensive.

For safety equipment, 5-point harnesses beat airbags in nearly all cases. No race car in the world is equipped with air bags, despite the fact that speeds are typically the highest in racing and therefore crash energy is the highest, yet modern race cars kill far fewer people than highway cars at equivalent speed. A 70mph crash in a race car is a non-event. No injury more severe than a concussion would be expected. The car is trash but the occupant walks away in nearly all cases.

If we decide to move to something truly sustainable, that's going to be steam and liquid air power. It requires greater material throughput than hydrocarbon fuels or batteries, but the starting point and ending point of the fuel's lifecycle is precisely the same. All of it is "recycled" using only the power required to collect it in the first place. The "fuel" came from and is subsequently is returned to the Earth, as-is. After the equipment is built to extract and store the liquid air and hot water, it is by far the most environmentally friendly and long-term sustainable solution. None of the byproducts are toxic, it requires no additional mining, and any time we have an accidental "fuel leak", we stand back and watch, because the end result will come to a good bit of nothing.

Vehicles powered by air and water can be exceptionally long-lasting. Apart from the electrical system for lights, the rest of the vehicle can be entirely mechanical. Even windshield wiper motors could be air-powered, although the current electric ones do their job admirably well and I see no good reason to replace what works, "just because". It's hard to imagine an overall simpler vehicle design, one one with fewer failure modes, and the fewest catastrophic failure modes, which typically don't involve a fire, unlike electronic or combustion engine vehicles. That's not to say it's "less dangerous", because liquid Nitrogen and boiling hot water can certainly be dangerous, but fire produces far more fatalities than boiling hot water.

My reasoning behind doing this is NOT that I think air and water are "better" than hydrocarbon fuels, but that the energy cost associated with obtaining the fuel is limited to collection, there will never be a shortage of it if the solar thermal and nuclear thermal plants continue to produce, and any objections over toxicity or other environmental harm should be a moot point, since it literally is "the environment" we interact with the most on an everyday basis.

Even if I had to fill up my car every other day, so long as the "fuel" was very cheap, it would make little difference in the grand scheme of things. It should always be available when needed, no price volatility since it's a locally produced and consumed good / service (can be vertically integrated) rather than globally traded commodity with a supply chain stretching around the world a time or two, and any periodic loss of the commodity is an annoyance rather than an emergency.

kbd512 · 2023-03-18 01:51:33

Calliban,

Both you and tahanson43206 pointed out that for boiling hot water powered vehicles that also use LN2, the rate of heat transfer becomes the limiting factor and you need a substantial heat sink and heat exchanger to supply continuous power to the locomotive's air turbine.

How about an alternate solution that only uses hot water?

If we raise the pressure of the boiling water tender tanker cars to 850psi, such that water remains liquid at 274C, and use CO2 as the heat transfer fluid to transfer thermal power to a supercritical CO2 turbine, then we get our 200Wh/kg without any cryogenic liquids involved. We use the atmosphere as our cold sink, instead of a separate water tank. We need 6 DOT-105 spec pressurized / insulated tanker cars to stay under the load limit for the tanker cars and the railway.

The tanker car steel is listed as TC128 Grade B, with a nominal thickness of 0.775". I think we need to use HY-100 steel for 850psi boiling water to keep the hoop stress below 80ksi. I assume any type of steel gets weaker as temperature increases. We're starting off at 274C. I'm assuming we've lost about 10% of our steel's tensile strength by about 300C. Is that ballpark accurate? US DOT regulations apply here, but what about boiler codes for construction of these tanks?

I then need 400m^3 / 400,000kg / 105,669 US gallons of 274C pressurized water to equal the mechanical work output that GE's 7FDL-16 diesel engine extracts from 5,000 gallons of diesel fuel. Our hot water provides 200Wh/kg, using 274C to 27C in our energy density calculation. I also assume a 70% overall efficiency in conversion of thermal to mechanical power, but this time using a sCO2 turbine which draws heat from the hot water tanks and exchanges it with the atmosphere instead of rapidly expanding Nitrogen exchanging heat with 100C hot water tanker cars.

I thought about doing it this way because:

1. No liquid Nitrogen is involved here. This makes everything much easier because there are fewer potential problems associated with freezing things.
2. The water stays in the tanker cars and doesn't need to be drained, so less exposure of personnel and equipment to extreme temperatures, less possibility of contamination causing corrosion in carefully filtered water that could have all impurities and Oxygen removed since it's staying inside the tanker cars.
3. We will use electricity to dump thermal energy into the hot water tankers, so we don't need solar thermal infrastructure or heat exchangers at the railway stations servicing the locomotives. All that stuff can stay in the desert out west, where it belongs.
4. There's no super-heated LN2 escaping at 12 gauge shotgun shell chamber pressures, so we don't need the world's biggest muffler attached to the exhaust system from the power turbine, because there is no exhaust.
5. It's a lot easier to keep hot water hot, than it is to keep cryogenic liquids cold. We don't need additional equipment to liquefy air, so no "biting the bullet" on efficiency losses therein. The solar thermal system will transfer power into the existing electric grid, so dumping heat via electrical resistance into the hot water tanker cars can be facilitated that way.
6. A sCO2 power turbine's power density is much greater than a comparable air turbine expander. We could feasibly use the existing electric traction motors from the existing trains, keeping as much of the existing technology set in place.
7. The existing fleet of nuclear reactors can participate in providing "fuel" for locomotives and trucks. We need some way to "charge up" the first generation of this technology, before we commit to building additional solar thermal and nuclear thermal infrastructure. Almost any existing reactor can already provide the hot water for the "proof of concept" demonstrator trains, trucks, and passenger vehicles. Maybe we can demonstrate that commercial power reactors can pull double duty supplying hot water for transportation and electricity.

Anyway, this concept is my "Take 2" on a sustainable freight train.

tahanson43206 · 2023-03-18 06:22:04

For Calliban re the pressurized hot water energy storage system proposed by kbd512 in #10 ...

Could this system also work as an energy storage system at a fixed installation?

It seems (at first reading) to make use of abundant materials which should reduce cost, and it has no toxic materials that I could see.

A figure of 70% efficiency in turnaround of electricity seems a bit lower than a battery might provide, but the offset values of materials choice might make the system attractive for rapid energy buffering.

I am looking forward to your evaluation of the concept for a freight train, or for certain kinds of water transport.

All in all, this idea seems (to me at least) right up there in Void class.

(th)

Calliban · 2023-03-18 07:36:41

It sounds like a good idea. I will give it more detailed consideration this evening. It offers improved volumetric heat capacity to LN2. The only downside is the need for a steel pressure vessel which adds to weight and cost. That eats into effective mass energy density. A hydro tested pressure vessel is needed, because the superheated water is a potential bomb. As a stationary energy storage system, stored hot water would work well as steam can be bled directly into a swirl vane type dryer and into a multistage turbine. It would work even better if condenser heat can be used as space heating.

I am not sure about the efficacy of S-CO2 at temperatures much lower than 500°C. It certainly has power density and efficiency advantages over steam cycles at temperature greater than 500°C. Hot CO2 is also less corrosive that steam.

tahanson43206 · 2023-03-18 08:22:29

For Caliban re #12

In the theme of permanent installations, kbd512's concept seems (to me at this point) like a good candidate for an energy storage system for a fixed location. The bomblike quality of the storage device can be mitigated by enclosing the device in a mass of regolith, which would be normal practice on Mars.

A detail of design which I hope you will describe, is how to valve input and output to this device. Input needs to be fed into the tank against whatever pressure exists at the time of resupply, and the output to turbine equipment needs to be as robust as the tank itself.

One option for intake might be to simply run the tank until it is empty, and then refill it from the discharge tank, which I gather from kbd512's description, is intended to make this a closed loop system.

To add to your evening calculations ... is there (by any chance) a sweet spot for size of this installation?

The tradeoffs are mass required, and investment in quality of materials and manufacture to insure reliability under load, plus potential RUD effects that can be predicted.

There are likely to be other tradeoffs I'm not aware of.

kbd512's train locomotive provides size constraints based upon standard railroad gauge, but a fixed site installation could be larger.

(th)

SpaceNut · 2023-03-18 08:35:46

This would put an end to planned obsolesce for sure but the reality is manufacturing only sustains by constant changing and making things inferior so that they break.

After the draughts that did hit the US we can see that making use of fresh water is not a good thing for power creation when one needs drinking water. In the same token with the recent CA floods from snow melt and rain we also see that we need water infrastructure to be built to command these conditions to holding lakes to ponds, a redirection system to other parts fo the nation where more land is open for the same projects to create as well.

Solutions to what other working fluids will come but its about how cheaply these system with them that is the issue as its about the energy to do so. Whether LN2, S-Co2, molten sodium and many others to be made use of.

Our issue is the form of the energy that one needs on tap. whether this is diesel, gasoline, electrical AC or DC or any others. We all use these in peaks and not average so that means the system that create also has to have the ability to provide for these conditions that are not steady state constant.

If you have to keep just 1 form of this to provide for all energy uses one would need a variety of conversions to make the ability to change it to hot water, electrical power, heating, cooling ect just to name a few and for transportation use.

So what is that starting total in Kwhrs. gallons, ect with conversion loss accounted for that is the issue and not just its supply or creation of this source or its cost to provide.

Of course, in this period of time rather than quantity we are more concerned with its cost as we are all going through this energy starvation due to how many dollars, we have to keep oneself happy and safe in comfort rather than in the poor house of homelessness. We know that we cannot trust the energy providers no matter what form it comes in to control the costs so it's up to the individual to manage the use and creation at their level to keep from being on that wrong side of the fence.

kbd512 · 2023-03-18 13:44:25

Calliban,

My suspicion is that US DOT-105 tanker cars are already made of steel of sufficient thickness if HY-100 steel was used in lieu of TC128 Grade B. There will be no weight penalty imposed above / beyond having 6 of those DOT-105 tanker cars behind each locomotive. Freight trains already have 100+ cars per train, some as many as 200, so the total increase in mass imposed by using pressurized hot water is still small when compared to the total mass of the rest of the train.

This is a compromise solution. Some people don't want burning of hydrocarbon fuels. I don't think fighting them on this point is worth it if there's a viable alternative, especially one that does not use and scarce materials or result in burning of extra hydrocarbon fuels to obtain scarce materials. However, it must indeed be a viable alternative. It cannot be substantially worse than Lithium-ion batteries. It cannot ask for quantities of technology metals that the Earth cannot provide. We can't source enough Copper, Aluminum, or Lithium. We need a viable alternative which is reasonably low-cost, non-toxic, minimizes pollution.

Building these new machines is how we keep our planned obsolescence economic model temporarily satisfied while stealthily building one for planned foreverance. The simplicity of the machines, abundance of the materials required, and the US DOT code / law for pressurized tanks will ensure that the major components of cars, trucks, trains are durable and strong.

For a much lower operating pressure by using 250C initial temperatures, we can create a car that stores 106kWh worth of power for a personal short-range transport vehicle, via 650kg / 171.5 US gallons of hot water at 250C. This is perfectly doable. Will the car be heavy? Yes. Will the car be substantially heavier than a battery powered vehicle? Actually, no, it won't.

Americans already consume more water than 171.5gpd in many cases. This is a one-time investment of pure water, to be electrically heated thereafter. We can source the CO2 for the thermal power transfer loop from the atmosphere, if need be, or from our nearest gas turbine power plant. It uses high strength low alloy steel for the tanks, Aluminum for the radiator and wheels, and maybe some stainless for the sCO2 power turbine, but high strength alloy steel is fine for that, too. Car makers have already switched back to using alloy steel from Aluminum.

The vehicle can be recharged as fast as the water can accept thermal power input from an embedded electrical resistance heater. This keeps our electric everything crowed happy. The vehicle is still primarily electric, it's just not battery powered, because that requires more Copper / Aluminum / Lithium / Sodium than we could realistically mine over centuries to thousands of years.

Again, this is about compromises with people who want certain things. We're delivering what they say they want, but in a different way, giving them the same end result for far less money, far less environmental destruction, and frankly, far less burning of more hydrocarbon fuels since mining is exclusively done with coal, gas, and diesel. We will not run out of steel or Aluminum, or any of our technology metals, if we do it this way. All the other ways are blocked by unsolvable math problems. I don't have a dog in this fight from any ideological standpoint. I'm proposing alternate solutions that can actually work, because I prefer that my math problems come with solutions. I don't like math problems with no solutions, because working the problem doesn't provide usable results.

All I've done is the basic math that these people should've done, but didn't, to arrive at a practical solution that works for everyone. Other much smarter men came to similar conclusions long before I ever did (which I only found out about through researching this problem), so both smart people (academics) and not so smart people (ordinary Joes like me) can solve these problems in practical ways. I don't have all the answers, and don't think any single person ever could, but I do have a broad general sense of what "right looks like". What we're presently doing is about as far from correct as we can possibly get. If the end goals include living within the material limits that the Earth imposes upon us, stopping the burning of excessive quantities of hydrocarbon fuels, and doing a better job of managing available resources to provide useful technology to the greatest possible number of people (the end result of capitalism over time, regardless of motivations), then this appears to be one of many feasible solutions. My proposals also happen to be much cheaper than "current thinking", which should appeal to economists and bankers and people living on a budget.

I'd love to have an electric car, but I can't afford one. They're too expensive, both up-front and later on when the piper must be paid as it relates to maintenance. This has relegated EVs to being expensive toys for wealthy people, like sports cars. Too many scarce technology metals, too many expensive technology gimmicks, not enough practical utility as a personal transport for the asking price. This proposal is essentially that promised but not delivered "EV for everyone" that doesn't ask for impossible things that cannot be done at a global scale, within the realm of energy, money, materials, and the natural environment.

tahanson43206 · 2023-03-18 14:21:14

For kbd512 ... You've been extending the range of this energy storage and return system from trains where you started, through other equipment and now you've surprised (me for sure) by considering automobiles.

I am hoping to (at least try to) encourage you to see if you can pursue this idea in the direction of a practical vehicle that someone would like to manufacture.

So ** that's ** one possibility.

In an even smaller scale .... I've been looking recently at 2000 watt generators for camping or job site power of hand tools. These appear to be affordably priced, and most run on either gasoline or propane (often switchable between the two).

Can your hot water design stretch down that far?

In another topic, SpaceNut and I've been thinking about portable power equipment.

A hot water system for energy storage and release might even prove attractive for Mars. I'm making an assumption here, that water is a superior material for your design, and at Mars, that might not be the case.

Calliban suggested omitting the CO2 leg of your design. You've indicated you'd prefer to keep it for large vehicles, but I'm wondering if a small application might run with just the direct steam cycle?

For a job site application, a pressurized container of hot water might be considered too great a risk?

On the other hand, a container of gasoline or propane has plenty of risk potential.

(th)

Calliban · 2023-03-19 13:46:27

I had hoped to get to this sooner, but weekends always end up being busy. A few calcs on the performance of a hot water powered freight train.

At 250°C, the saturation pressure of water is 40 bar(a). The specific enthalpy of saturated water at this temperature is 1087.24KJ/kg. Specific volume is 1.252litres/kg, which equates to a density of 800kg/m3. Suppose we use this superheated water to run a steam turbine, which receives dry steam at 250°C and has a condenser temperature of 30°C. The corresponding enthalpy of saturated water at 30°C is 137KJ/kg. I am going to assume that our small steam turbine can get half of Carnot efficiency, or 0.5 x 42% = 21% efficiency between these temperature limits. So, each kg of saturated water at 250°C, will generate some 230KJ of work energy. Each cubic metre, will contain some 187.3MJ work energy.

Data from:
https://officialbruinsshop.com/superheated-steam-table/

How much will the pressure tank weigh? According to this site, the DOT-111 tank car, which accounts for a large fraction of the US and Canadian tanker fleet, is 59' long and 10'8" in width, and holds 29,000 gallons. That is 18.15m long, 3.25m diameter and capacity 109,000 litres. So far, so good. Dead weight is listed as 86,350lb, or 39,168kg. The tank is pressure tested to 100psi (7.8bar(a)).
https://www.gbrx.com/wp-content/uploads … nk-Car.pdf

I am going to work out the extra weight of a pressure vessel needed to contain 32.2 bar and add it to the dead weight above. Our pressure vessel is a cylinder, consisting two hemispherical end caps, some 3.25m in diameter and a cylindrical shell, some 16.9m long and some 3.25m in diameter. Design factor is 3.5x UTS, as recommended here.
https://www.eng-tips.com/viewthread.cfm?qid=345631

The steel used will be ASTM A285, which is a low alloy carbon steel, with UTS of 480MPa.
https://masteel.co.uk/astm-a285/

Allowable stress is 137MPa, given a SF of 3.5. Using the thin walled pressure vessel equation to calculate wall thickness:

t = Pr/stress = 3.22MPa x 3.25 / 137MPa = 0.076m.

The surface area of the vessel is:

A = pi x 3.25^2 + pi x 3.25 x 16.9 = 3.25pi(3.25 + 16.9) = 205.74m2

Multiplying by wall thickness of 7.6cm and a density of 7800kg/m3 for steel, gives mass of 122 tonnes. Adding this to the 39.168 tonnes mass of the DOT-111, gives a total empty weight of 161.13 tonnes for our hot water rail car. That is for the chassis, wheels and tank all included. Adding some 109m3 of superheated water, takes total mass to 248.3 tonnes. The total work energy available from each tanker car is 20.416GJ. A gallon of diesel contains some 3.76 litres, and has heat of combustion of 38.6MJ/litre.
https://en.m.wikipedia.org/wiki/Energy_density

Assuming a 40% efficient diesel engine, 1 gallon of diesel will yield some 58MJ of work energy. So a 248 tonne hot water tanker car will carry as much available work energy as 352 gallons of diesel. How far would one of those tanker cars take a typical freight train?

Let us assume a total weight of 10,000 metric tonnes, including the hot water car. Rolling resistance of 0.0024 on a level track. I will ignore air resistance because we are dealing with a heavy, long vehicle.
https://en.m.wikipedia.org/wiki/Rolling_resistance

Total driving force of 235.44KN is needed to overcome rolling resistance. Energy consumption per km is force x distance, which will be 235.44MJ. So 1 tank car will power a 10KT train for some 86.7km. To get a 1000 mile range, which is 1609km, we would need some 18.56 tanker cars, weighing some 4600 tonnes.

If we set a reasonable limit of 10% total weight consisting of tanker cars, our hot water powered freight train would have a range of 217 miles between stops. Is that good enough for a typical freight run? What distances are we talking about?

Last edited by Calliban (2023-03-19 13:52:29)

tahanson43206 · 2023-03-19 14:27:39

For Calliban re kbd512 steam-stored-energy system

Re your Post #17

It seems to me such an engine would have natural role in a switching yard. It could replenish it's energy carrying tank car as often as needed.

I'm not sure this is a good fit for your topic, but I'm hoping it might quality.... in another topic, I've been inviting members to consider what it would take to deliver 20 AMs of electricity for an hour for a job site application. Candidates considered so far are traditional hydrocarbon fuels, and battery powered systems of various kinds.

Would you be willing to consider kbd512's idea in the context of a job site electricity supply?

I'm not sure such as system is commercially attractive, but it certainly ** ought ** to be physically achievable.

The energy store would be charged at a "home base" of some kind, such as the garage if electricity is available. In that case, "charging" the store would involve driving electric heaters until the liquid is hot enough for the application.

I am concerned about risks of this particular design, compared to the known risks of alternative systems.

(th)

Calliban · 2023-03-19 14:34:28

Houston to Kansas city is 650 miles. We would need a minimum of 12 hot water rail cars, weighing 2976 tonnes to drive a 10,000 tonne gross weight freight train. So 30% of total mass is hot water cars. Total train weight per kg freight would be 40% greater than a diesel train.

Calliban · 2023-03-19 15:44:01

Liquid nitrogen has an expansion energy of 770KJ/kg or 620KJ/litre, indicating a density of 805kg/m3. This assumes a reservoir temperature of 300K and perfect isothermal expansion. Maybe we could recover 70% of that energy with a practical device. Our 109,000 litre tanker car would then carry some 47.3GJ of recoverable work energy, vs 20.416 for the hot water car. This is over twice as high as our hot water tanker. But the nitrogen can be carried in a tanker at ambient pressure. So in addition to having higher volumetric energy density, it would have much higher mass energy density. A DOT-111 carrying a 109m3 of LN2 would weigh 126.913 tonnes. This is only 51% of the weight of the hot water car. So a liquid nitrogen power source has 4.5x greater mass energy density than a hot water power source. That assumes we can recover 70% of stored expansion energy. But assuming that we can, a 10,000 tonnes train with a 1000 mile range would need to carry 8 LN2 tanker cars weighing a total of 1015 tonnes. That is 10% of total train weight. Far more achievable.

This train would need to absorb heat from its surroundings to evaporate the nitrogen. Could it do that? Let us assume heat transfer by radiation, a background temperature of 10°C (283.2K) and a panel temperature of 273.2K. Radiated heat flux from the surroundings at this temperature difference is 48.84W/m2. Our expansion cycle is 70% efficient, so every 48.84W absorbed from the surroundings will generate 34.2W of engine power. How much engine power do we need? If our train travels at 30mph, that is 13.4m/s. Total driving force is 235.44KN. So 13.4 x 235,440 = 3.16MW engine power, or 4238HP. The train will need 92,300m2 of absorber panels. Lets us assume a height of 4m and width 3.25m for a box car. Each metre of train length equate to 14.5m2 of outer area. For 92,300m2 of absorber panels, the train must be 6.37km, or 4 miles long.

The longest trains to operate in the US are 3658m long. So I conclude that to be efficient, LN2 trains either need to travel more slowly than 30mph, or include a supplemental heat source. A hybrid option, with both hot water cars and LN2 cars could provide a solution.
https://en.m.wikipedia.org/wiki/Longest_trains

A diesel-LN2 hybrid is an attractive option, because a diesel engine generates lots of waste heat at relatively high temperatures. With a diesel hybrid, the 60% of waste heat produced by the diesel engine, provides the expansion heat needed by the nitrogen engine. If 70% of that heat is converted into mechanical power, then we can effectively double the distance travelled per gallon of diesel fuel. Diesel exhaust can reach a temperature of 650°C. So a diesel-LN2 hybrid would need a lot less liquid nitrogen per km travelled.

Last edited by Calliban (2023-03-19 16:22:11)

Calliban · 2023-03-19 16:36:18

For stationary energy storage. We have discussed hot rock energy storage before. Quartz has specific heat about 1KJ/Kg.K between the temperatures of 600 - 1200°C. For a stationary energy store, you could have a cylindrical silo made from steel filled with crushed quartz. Dry sand around the silo would provide thermal insulation. Run stainless steel pipes through the silo containing sodium at 600°C. Sodium doesn't boil until ~800°C, so the tubes do not need to sustain any internal pressure. The sodium would carry heat into a CO2 heat exchanger, which would drive an S-CO2 power generation cycle at about 600°C. Efficiency would be ~45%. The waste heat can be put into deep boreholes and used for winter heating or used as evaporation heat for LN2 power generation.

kbd512 · 2023-03-19 20:07:17

Calliban,

This proposed system is not a steam engine. It operates in a closed loop and transfers thermal power from the hot water tanks to a radiator exchanging heat from the hot water with the atmosphere at whatever ambient temperature happens to be. The hot water is initially heated to 275C using a resistive electrical heating element inside the tanker cars, which implies 850psi to keep the water liquid. Inside the hot water tanker cars, we also have pipes containing supercritical CO2, which carries the heat energy from the hot water to the radiator assembly and power turbine installed in the locomotive chassis. The sCO2 drives the power turbine after the heat exchange through the radiator. The power turbine is connected to mechanical gearing or a hydraulic motor or an electric generator to produce tractive effort. The reason for using sCO2 is what will happen if pure water ever freezes inside the radiator assembly or transfer lines from the hot water tanker cars. The sCO2 will never freeze, even if it was operated on Antarctica. The hot water tanker cars need sufficient void space to allow for thermal expansion of water, if per chance they're allowed to sit idle long enough for the water to freeze. The hot water tanker cars are essentially sealed after very pure water is added to them. They will get reheated / recharged, as-required, using embedded electrical resistance heating elements.

DOT-111 tanker cars are not rated for the pressures involved. The 18,000 gallon DOT-105 tanker cars are tested to between 500psi and 600psi. They're made from 0.775" thick AAR Plate B / AAR TC128 Grade B steel plate. I need 850psi at 275C, which is why I proposed using HY-100 steel, which yields at 100ksi, minimum. 18,000 US gallon (17,360 US gallons water capacity, as tested in a side-impact crash analysis conducted by US DOT) DOT-105 tanker cars nominally weigh 93,840lbs, empty. If the tank was made from HY-100 steel instead of TC128 Grade B, then the hoop stress on the inside of a tank pressurized to 850psi, with a nominal 106" ID, is 33.6ksi using 1.375" thick steel. UTS for HY-100 is 125ksi / 861.845mpa. To meet the boiler code safety factor you cited, the steel would need to be 1.375" thick vs 0.775" thick. The empty pressure vessel would weigh 74,456lbs / 33,773kg. The existing DOT-105 pressure vessel would weigh 38,074lbs / 17,270kg. That's a weight increase of 36,382lbs, so the empty tanker car now weighs 130,222lbs. To that, I add 17,000 gallons / 141,610lbs of water, so 271,832lbs total, which remains below the gross rail load limit of 286,000lbs per car.

Calliban · 2023-03-20 03:12:36

Kbd512, my analysis may need refinement. I had started with a tank car that was pressure tested to 100psi and then added the extra weight of a pressure vessel needed for 40bar(a) pressure containment. I suspect I may have double counted. My analysis suggested the car would be twice as heavy as your calculations suggest.

Either way, your hot water rail car idea would work. It has the advantage of being a simple technology. Steel pressure vessels have long life, so the tank car should be usable for decades. The S-CO2 power system would cost money to develop, but once developed is really no more complex than a diesel engine. The operating temperatures may be too low for efficient operation with S-CO2. But there are other working fluids that could be used.

kbd512 · 2023-03-20 12:14:10

Calliban,

I mentioned using DOT-111 tanker cars, which was my mistake. I quickly realized that from the US DOT crash test report on that type of tanker car, which specifies weights / volumes / steel grade and thickness / etc. DOT-111 tanker cars are both not rated for similar pressures and would be well over the per-car gross rail load limit of 286,000lbs, because they were intended to carry lighter liquid hydrocarbon products at modest to no internal pressure. To correct that mistake, I then proposed using DOT-105 tanker cars, which were rated to handle similar pressures, but still not strong enough. The weight added to each DOT-105 tanker car almost doubles the weight of the pressure vessel to conform to ASME boiler code for pressure vessels, so your note about needing to double the pressure vessel weight was pretty accurate.

I figured that both the grade of steel and its thickness would be insufficient to meet ASME code for construction of boiler pressure vessels, which is why I asked that question of you. My non-educated guess was that ASME boiler code would apply to this particular heated pressure vessel. The statement of applicability from a 2019 copy of the code confirmed my guess.

This was always going to be a very sub-optimal solution compared to a diesel engine. I merely wanted to know, "How bad is it?", and is it significantly worse than the only alternative on offer, which is electro-chemical batteries. There are lots of solutions which involve burning something, but whether that works is not in question. I'm not trying to completely eliminate use of hydrocarbon fuels, because they're absolutely necessary for specific applications, like rockets, for example. All I want to know is if we can run most aspects of daily life off of appropriate applications of hot water and electricity which is not stored in batteries. Can we devise a solution that gives every major constituency some of what they want? Electricity for our electronic gadget-philes, simple transport systems for sake of affordability to the masses to go to work / raise children / etc, solar thermal for people who want to do renewable energy, nuclear thermal energy for reliable baseload so storing huge amounts of energy is not required, and truly sustainable systems so that the environment isn't wrecked in the process of trying to deliver this "future state", which doesn't presently exist at anything approaching the required scale.

After the objections raised by TH, I dropped the idea of using LN2. His concerns are perfectly understandable, and the practicality of doing that has never been demonstrated at sufficient scale to properly evaluate. I think use and consumption of large volumes of cryogenic liquids is likely to be more sub-optimal than electrically-heated hot water, but I'm refining ideas and concepts that could potentially work. Some will inevitably be more practical than others. I'm trying to arrive at the most practical ideas we can put forward as alternatives to non-solutions involving electronics and electro-chemical batteries.

The proposal to use sCO2 as the working fluid came down to a combination of factors- very dense, non-toxic, non-freezable (at normal atmospheric temperatures and the elevated pressures inside the thermal power transfer loop), and it's a refrigerant presently in widespread use. It probably isn't the best, but it can't ignite or freeze or easily poison anyone. Perhaps Nitrogen is a better option. I don't think typical refrigerants like Freon would work well at 275C, but I could be wrong.

People want electric stuff, so I evaluated whether or not electricity could be used to "recharge" the hot water with heat more efficiently than all the transfer infrastructure required for direct replacement of the hot water, and that looks like a much more realistic option, especially for the temperatures and pressures involved to make a practical land motorized vehicle (car / truck / train). I'm not opposed to things that can actually work at scale. You still visit your "Tesla SuperCharger" instead of a gas pump, to "recharge" your hot water car, and you're still driving an EV for all intents and purposes, but the electricity is heating up a tank of hot water. The part that's missing is all the electronics required to ensure you don't blow up the battery. This new EV has its own hazards from its hot water pressure vessel, but electrocution from working on the car and fire are far less likely. When it gets cold, range goes up, not down, so it's opposite of Lithium-ion batteries. Pressure is high, but not crazy-high as with Hydrogen gas for a fuel cell, and water is not flammable. You can get a "ka-Boom!" from gasoline / diesel / pressure vessels / batteries, so no real change there. Having lots of stored energy is always potentially dangerous. Your range never degrades over time, because a "hot water battery" always stores the same amount of energy if it's heated to the same temperature. The only failure mode is putting a hole in the pressure vessel or radiator. ICEs and EVs both use radiators, so no change there. If you put a hole in gas tank or battery, that will also kill a combustion engine or battery powered vehicle. The hot water tank can never "short circuit" or "die", so it's immune to the types of failures that would kill an electro-chemical battery. You can discharge it to zero power every single time, but so long as you recharge it to a specified temperature, it's 100% good-to-go. So long as the water volume is appropriate to total tank volume (10% less water than total tank capacity), the hot water battery won't rupture from freezing solid. It's the closest thing to "unkillable" that I could come up with.

I view electro-chemical batteries as a non-solution once it's scaled-up to the degree required to actually replace anything. My non-educated guess was that Lithium-ion batteries were not viable. I spent about 10 years hunting for miraculous new battery tech. So far as I can tell, we have no miracle batteries. I gave up on that and then started looking into alternatives. My tirade / rant against the very real but vastly under-appreciated software and electronics complexity was directly related to the maintainability of anything approaching a workable solution. I have enough first-hand experience with software design for non-trivial complexity business applications to know what I'm talking about when it comes to electronics and software complexity, especially software. Failure modes include a very lengthy list of possibilities, some of which have no solutions.

I then learned that my opinion was shared by a French PhD about 10 years ago in EU working groups on renewable / sustainable energy. Now a highly educated double-PhD college professor, with the benefit of actually working in the mining industry for over 10 years, named Simon Michaux, has re-confirmed my dim view of batteries using simple math. Moreover, he confirmed that no advanced math was even required to understand the nature of the problem. The Frenchman stated the same thing when he was talking to the people in EU government when they attempted to "whatabout" his answers and assertions about the nature of the problem and what solutions were viable. Dr Michaux stated that Algebra was going a step beyond what was required to understand and characterize the problem. He said it's a straight engineering calculation involving add / subtract / multiply / divide, and that no Algebra or other higher-level math was involved. Nobody did their homework on what they were proposing. Dr. Michaux straight up told anyone who would listen, "You're not going to make batteries out of Lithium, so pick another metal that we have a lot more of."

This annoys me to no end, because I want my own children to have a better future. I know that any technologically advanced future starts with energy. Without energy, nothing is possible. With sufficient energy, many things are possible- solving our environmental problems here, living on Mars, and eventually exploring the stars. This renewable / sustainable energy ideology / movement is completely blind to where the energy and materials come from. They hold cartoonish views of how the world works. Before large numbers of them suffer the consequences of attempting to live in cartoon-land, I want viable alternatives put on the table for consideration by our decision makers. I only have a rough general idea of feasibility and what right might look like. Someone smarter and/or better educated than me might come up with much better solutions. To me, "better" accounts for availability of materials to begin with, total cost, and any serious practical limitations. Hot water tanks will never power practical aircraft, for example.

I use real-world examples quite often because those as-built machines, such as a tanker car, help people such as myself grasp the basics in a way that permits us to use simple math to determine how well an idea scales up, as well as answering those "How much will it cost?", "How many do we need?", "How long will it take to replace the existing system?" "What's it made from?", "Are we asking for more materials or labor than we have available?" types of questions.

Calliban · 2023-03-20 16:35:55

According to wiki, energy consumption per ton-mile for rail freight is 1/12th that of a heavy truck.
https://en.m.wikipedia.org/wiki/Energy_ … _transport

Total fuel consumption of Class 1 railroads is 3.4bn gallons per year. That amounts to 135,000GWh.
https://data.bts.gov/stories/s/Freight- … f7sr-d4s8/

This sounds like a lot, but considering that rail provides about one third of total ton-miles in the US, it really isn't. The superb energy efficiency of rail freight and the fact that it is carried in long, thin vehicles at modest speed, allows substantial flexibility in how we might choose to power such trains.

Case 1 - Biofuels. If we wanted to, we could fuel the entire US rail fleet from pyrolytic synthetic diesel, derived from a high yield biomass crop like miscanthus giganteus.
https://en.wikipedia.org/wiki/Miscanthus_giganteus

In the US, it will yield up to 22 dry tonnes per hectare on the best land, but 10 tonnes per hectare is a good average across the whole US. The entire US rail fleet could be fuelled by 6 million acres of miscanthus at average yield. That is 0.24% of US land area. More likely, a range of woody crops, forestry wastes and crop residues would be used. But the point is that rail freight is efficient enough to be sustainably powered by biofuels, even if it were scaled up considerably.

Case 2 - Hydrogen. Hydrogen is a weak contender for vehicle fuel, because electricity or fossil fuel is needed to make it. It also has really inconvenient properties. It is diffuse, difficult to compress or luquefy and leaks through seals and even solid metals. However, a train could be powered using hydrogen contained in gas bags at ambient pressure. At ambient pressure, hydrogen contains 11.5MJ/m3. Our 10,000 tonne train needs 235MJ of work energy per km travelled. Lets say the train is 3km long, and carriages are 3.25m wide. Each carriage is fitted with a gas bag 1m tall on the roof. That equate to about 9000m3 of hydrogen. Let us further assume that hydrogen is burned in a GT which is 33% efficient. How far would that hydrogen take us?

Range = (0.33 x 11.5MJ x 9000)/235MJ = 147km (91.7 miles).

Stopping to refill with hydrogen every 90 miles (3 hours) or so, would be cumbersome, but it could be made to work if refilling were a rapid process. I think it could be, as we are dealing with hydrogen at ambient pressure and blowing the gas through a large diameter but thin walled tube into the gas bags at the top of the train.

Case 3 - Direct electrification. By this I mean direct power from the grid. No batteries. I have no idea how much this would cost capital wise. To pull 10,000 tonnes at constant speed of 30mph over a zero gradient, about 3MW of power are needed. This could be provided by DC third rail at 750V. But this is about the upper limit of what third rail can do without upping the voltage. The dowside to third rail is that voltage drop neccesitates a transformer station every 1-3 miles along the track. That pushes up cost. And trespassers frequently electrocute tyemselves on the tracks. For these reasons, most electrification schemes opt for cateneries, especially for freight. Ignoring transmission losses and assuming a 90% motor efficiency, about 60TWh of electricity would be needed to power Class 1 US freight railroads. Adding a 10% distribution loss takes us to 66TWh. That is 7.5GW of continuous power, or some six Westinghouse 1250MWe PWRs. If we scaled up rail to meet two thirds of US freight transportation ton-miles, then a dozen nuclear reactors could power the whole lot, assuming all lines were electrified. Electrification is at least a COTS technology and the US could command huge scale economies.

Other options.

1. I have looked at liquid nitrogen. It can be stored at ambient pressure. Problems here are getting enough heat flux into the train to raise enough power at good efficiency. Hybrid options are possible or we could run the train more slowly - 20km/h perhaps?

2. I looked into compressed air at 40 bar(g). A 109m3 rail tanker containing compressed air at 40 bar would contain some 1.6GJ of expansion energy. That is less than 1/10th of the work energy contained in our hot water powered rail trucks. So compressed air doesn't fit the bill.

3. Biogas or natural gas (they are both methane) contained in flexible bags similar to what we have assumed for hydrogen, would provide 3.28x greater volumetric energy density. So a gas bag train running on biogas could get a 300 mile range between refillings. The really cool thing about this is that the methane is lighter than air, so doesn't weigh anything. And the container is a lightweight flexible bag under some kind of canopy.

4. Trains could be powered using a small onboard gassifier, which provides fuel gas to a GT or spark ignition engine. In this case, any raw biomass could serve as fuel. This is attractive in many ways, because trains coukd be fuelled with whatever woody waste happens to be available locally. But it is a cumbersome solution. A boiler stoker would need to shovel the biomass into the gassifier. If biomass can be compressed into regularly shaped fuel cartridges, then a more automated loading process is possible. Charcoal is another variation on this.

5. Hot water powered rail trucks (250°C) would work. If the power cycle is only 21% efficient and the water trucks account for 20% of teain mass, then effective range is 434 miles between refilling. This might be sufficient, as it allows 14.5 hours of travel at 30mph.

6. A solar powered train, or solar assisted train is a possibility. If we mount solar panels on top of a 3km long train, then total panel area will be 9000m2. Assuming an average sokar flux of 500W/m2 during day and 20% efficiency, the panels will generate some 900kW on average. It might be worth having, so long as the panels don't add too much weight to the carriages.

I am edging towards biogas / natural gas as the fuel source. Natural gas is much cheaper than diesel as a fuel. We can carry it in flexible bags that weigh very little. And speed is low enough for drag not to be an issue either. But this is only suitable for closed carriages, where a bag can go on the roof. For open trucks it isn't a practical option. Liquefied natural gas could be used, with biogas gradually replacing it over time.

Electrification is a COTS solution that is already applied across much of the world. We don't need millions of tonnes of batteries to make this work. But a fair amount of copper is going to be needed. About one third of all railway track is electrified, globally. So electrifying more of the US railways would be a case of extending an existing technology.

Last edited by Calliban (2023-03-20 17:31:33)

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