Limestone-based Thermal Battery

SpaceNut · 2023-06-16 19:23:51

Why are we chasing steam as its not getting efficiency of energy use greater to cause a lower cost to operate?

Also, no trailers as that makes for more power connection issues for making the vehicle move as power or pressure lines would need to not only travel from the trailer but to the motor. Plus tonnes for mass is self defeating for movement

tahanson43206 · 2023-06-16 19:28:27

For SpaceNut re #76

Are you wanting a cubic meter of white hot limestone in the vehicle cabin with you and your family?

(th)

tahanson43206 · 2023-06-16 19:44:29

For Calliban and kbd512 ....

SpaceNut's comment in post #76 inspired a thought that I'm hoping might be of interest ....

Calliban suggested mounting the white hot limestone container in a trailer, to keep it out of the passenger cabin of a land vehicle.

SpaceNut's objections to a trailer to supply power are well founded and worth considering as this project develops.

However, trailers are routinely rented by Americans and owned by many, so pulling a trailer would not be a show stopper for many if not most Americans. I can't speak to other nations, so hope that residents of other nations will comment one way or the other.

My suggestion is to make the power trailer self motivating. In other words, it can supply power to the towing vehicle, without imposing drag upon the towing vehicle. This would require a high order of computer control, but we live in a time when massive computing power is available for very small sums of monetary units.

With this suggestion in mind, ** any ** existing electric car could be supported by a power trailer, which would be swapped for a fully charged one at the local electric charging station.

In other words, instead of re-inventing the automotive industry, this topic ** could ** lead to a re-invention of the electric supply for electric vehicle industry.

If you were to set a goal of providing electric power for a Tesla (or any EV) for 500 miles (804+ kilometers) what size would such a trailer have to be? If you include liquid air as the coolant for your power transformation, what difference would that make?

(th)

SpaceNut · 2023-06-17 07:51:30

One issue to also consider is that at that much mass you are going to need a forklift or crane to move the system to a trailer rather than building something somewhat smaller along the lines of a gas tank sized blade system that one can move with 2 people per blade assembly.

A blade design allows for a module size build for range and repair seems to be the right direction.

What is the mass of a Tesla battery system? Since that is what you are trying to replace. If the replacement weighs more than that we are not going to get the same efficiency as rolling with more mass reduces mileage.

If we need more isolation, then a car is not the answer, but a van would be as you have plenty more space to use in the back.
The hot container is already got a vacuum bottle design isolating the tank from the outer surface much like your electric oven so adding another layer of insulation between that and any passengers should be fine.

Is the design a travel or commuter car makes quite a bit of difference for sizing of heat source and for recharging the system.

I was looking for commuter vehicle and if you park like in a good solar location then recharging is free with something like these.

something that appears to be foldable.
41oqUXAJevL._AC_.jpg

Something that you might be able to take apart
99ab7f12-37c8-4e4f-8106-990481ec1aee.7e90e803daac99b8db06f436cdc95a92.jpeg?odnHeight=612&odnWidth=612&odnBg=FFFFFF

The average amount of gas for work commute is 4 gallons a day and at the post 72 has 33.7kwhr or 1 gallon of fuel at a 32% means we get to use this much energy a day of 44 kwhr or 11 kw for each gallon used. KBD512 is looking to use a 20kw motor which means that if we produced even that as a minimum from sand, or limestone. We have achieved the same goal as gasoline at hopefully less cost.

That said we should be able to solve to the battery size and other values in time.

SpaceNut · 2023-06-17 17:21:40

Working fluid selection of Mineral oil range of operation.
https://en.wikipedia.org/wiki/Mineral_oil

mineral oil ranges from 2.3 at 50 °C (122 °F) to 2.1 at 200 °C (392 °F)

https://www.motortrend.com/how-to/engin … mperature/
https://waynesgarage.com/tips/more-tip/synthetic-oils
https://anderol.com/news/how-to-determi … emperature

Synthetic oils can handle higher operating temperatures than mineral-based oils without oxidizing or breaking down. The upper limit for most mineral-based oils is about 250 to 300 degrees F, while synthetics can take up to 450 degrees F or higher. Synthetic lubricants are suitable for operating temperatures up to -30°C and have better low temperature performance than mineral oils3. Full-synthetic oil can withstand sump temperatures in excess of 300 degrees, and some race teams are experimenting with ultra-thin, specially formulated, race-only synthetics operating at 350 degrees or even higher.

Looks like we are going to need to either lower the operation temperature of the limestone or come up with another selection.

SpaceNut · 2023-06-17 20:04:05

https://en.wikipedia.org/wiki/List_of_t … uctivities

THERMAL PROPERTIES OF ROCKS
https://pubs.usgs.gov/of/1988/0441/report.pdf

https://material-properties.org/limesto … ductivity/

https://www.naturalstoneinstitute.org/s … ns/rvalue/

SpaceNut · 2023-06-18 08:38:08

I think we need to fill in these project flow questions starting with KBD512 dream for post # 1.

Project Objective: Clearly define the objective of the project. What do you aim to achieve by the end of the project? In your example, the objective might be to?
Kbd512 wrote:
I'm starting this thread in response to a recommendation from Calliban that we create a separate thread to discuss the topic of thermal batteries made using low-cost / low-embodied energy materials for powering an alternative type of electric vehicle that primarily uses electricity to heat up a very low cost heat energy storage medium, such as limestone, which costs $10 to $55 per metric ton.
This topic was originally created to determine how to create a more cost-effective electric vehicle that was not powered by an internal combustion engine or electro-chemical batteries and computers. In the near future, I expect both liquid hydrocarbon fuels and the metals required to fabricate batteries and electronics to become even more scarce and prohibitively expensive than they already are. There are presently no good recycling solutions for Lithium-based electro-chemical batteries or electronics, and absolutely nothing remotely approaching 100% recyclability, which would be required to re-power any given sector of the global economy using low energy density sources.
This is of interest for both earthly uses and Mars exploration because it does not require high cost specialty materials or fabrication methods, the heat energy storage medium does not "wear out" over time the way all electro-chemical batteries do, and recycling the vehicle and energy storage material is so easy relative to electronics and other types of electrical machines.
I do not expect such problems to be adequately addressed or resolved before people belatedly recognize and finally accept that any globally-applicable low energy density power and propulsion solutions require very cheap and very abundant and very easy-to-recycle materials and mining activities. Low energy density solutions effectively limit us to very simplistic heat engines and durable goods that last all or most of a human lifetime.
Scope: Determine the boundaries and extent of the project. What is included and excluded from the project? This helps to set realistic expectations and avoid scope creep.
Kbd512 wrote:
This type of battery is primarily intended to store thermal power in a vacuum jacketed steel tank using a resistive heating element embedded in the tank, which contains powdered limestone, so that the stored heat energy can be extracted using a thermal power transfer loop with the atmosphere being the cold sink, in conjunction with a small low-cost gas turbine, possibly using supercritical CO2 or some other fluid, to perform mechanical work to propel a passenger vehicle or electric generator, if the heat has been stored to provide stationary energy storage to power homes and buildings.
It's well known that this will never be as efficient as an electro-chemical battery, but the point of development is not to compete with Lithium for efficiency, it's to find a practical way to completely replace all of the existing passenger cars without running short of Lithium or Copper or other high-energy materials long before that could ever happen. A limestone battery simply cannot fail the same way that Lithium or Sodium or microelectronics do, so it's a worthwhile technology to have if it enables us to quit burning so much gasoline, diesel, and coal.

Deliverables: Identify the tangible or intangible outputs that will be produced as a result of the project. For the powering of a vehicle project, the deliverable would be the successful?
kbd512 wrote:
I'm creating this topic and invite commentary on thoughts about how to do this, or any related thermal battery technology that doesn't require complex fabrication methods and expensive / energy-intensive materials. I'm willing to forego absolute energy efficiency if it allows us to arrive at a more practical electric vehicle or supplemental energy store for our existing solar, wind, and nuclear power plants. A lot of power is squandered already because there is no practical storage mechanism, so some is better than none, and perfect is the mortal enemy of good enough to get the job done.
There's probably a reason why this thermal battery is so similar in operation to an internal combustion engine. That wasn't accidental. Assuming it's workable, automotive engineers would know how to make this technology work. It's not really "better" than combustion on efficiency, but it costs so much less to produce than the alternatives that it still allows us to make more affordable vehicles.
Mechanical valves could control the flow of sCO2 through the heat exchange loop, and possibly several loops on the same radiator dependent upon throttle setting, so it's not "running" at a stoplight, even though the radiator is still rather hot. For the radiator fans, I was thinking that residual thermal power from the CO2 could drive the fan as well, rather than another electric motor. I'm shooting for a completely mechanical engine and power train.

Timeline: Create a timeline or schedule that outlines the project's key milestones and deadlines. This helps to track progress and ensure timely completion of tasks.
TBD Note funds for self-produced indicated.
Resources: Identify the resources required to execute the project. This includes any equipment, tools, materials, or expertise needed. For the project, you might need appropriate safety equipment, tools for disassembly, and potentially professional assistance.
kbd512 wrote:
We can use A36 steel tubing because that's easy to weld and readily available. It doesn't need to last forever or meet specific performance targets. It's a basic technology demonstrator project. We'll use whatever materials we can get from the local hardware stores. If the demonstrator can be made with materials of nominal value, to illustrate basic function, then we can worry about scaling up and building integrated prototype vehicles.
Thermal Energy Store Materials
Thermal store will be powdered limestone - I'm sure it's not the best, but I can get it in bulk from a local farming supply store. I'll vibrate the container to settle / pack it as well as I can. I'll weld in a bung to vacuum out the tank. We're going with 100kg of limestone as a 10% scale demonstrator. At 2.4g/cm^3, 100kg of limestone should be equal to approximately 11 US gallons of internal tank volume.
Thermal store jacket - 304L sheet with a 0.024 or 0.025 thickness - This will not be some highly optimized geometry like a sphere, rather a tank that looks a lot like the diesel tank slung under a train. I'll use ribbing for reinforcement of the tank. A 55 gallon stainless steel drum is $900 to $1,500 before shipping, so that's out of the question.
Thermal store insulation - rock wool - It's definitely not as good as a vacuum jacket, but no complex engineering is required for that and I can get it from local hardware stores. If Calliban or GW can come up with the calculations required to ensure that the vacuum jacket doesn't implode, then I'll attempt to fabricate a vacuum jacket. Try to devise something that uses simple geometry that I can actually weld and have welded before, like bits of angle Iron welded to a sheet, or something like that. If we do use a vacuum jacket, I'm not spending money on more 304, so it needs to be made from A36 (basic automotive sheet metal).
Thermal Power Transfer Loop
In-tank plumbing - 0.25" OD 304L seamless pipe / tubing with 0.065" wall thickness - My back-of-the-envelope math says 304L has about 50% to 55% of room temperature yield strength between 500C and 600C, so 0.65" wall seamless stainless pipe / tubing exceeds the 2.5X ASME safety factor for expected sCO2 pressure after the strength reduction is accounted for. Again, I'm sure it's not ideal, but I can get the material.
Radiator - 0.125" OD 304L seamless tubing. I'm having a brain fart and can't remember the wall thickness I intended to use. My browser crashed, so I'm redoing this form memory. I'll make sure the 2.5X safety factor is adhered to. I intend to use some thin 304L sheet to make fins for the radiator. I've never brazed stainless before, so not sure how well that'll go. Maybe we can get away with a press-fit. I've seen press-fit stainless electric strip heating elements built that way.
Heating element - FeCrAl wiring - It's cheap, can be formed easily, and can withstand the temperatures required.
Risk Assessment: Identify potential risks and obstacles that may impact the project's success. Assess the likelihood and potential impact of each risk, and develop mitigation strategies to address them.
kbd512 wrote:
What you're describing is a combination of the cost and expertise required to translate our ideas into working hardware. Expecting one person to fill the roles of a mechanical or aerospace engineer, an electrical engineer, a computer programmer, a machinist, a welder, a graphic designer / artist, and whatever else is required is asking for quite a lot. There are obviously some people out there with that combination of skills, but not very many.
Communication: Establish a communication plan to ensure effective and regular communication among project team members. Determine how progress updates, setbacks, and challenges will be reported and shared.
kbd512 wrote:
We should hold a meeting on design specifications, materials selection, and any compromises we make in the name of practicality and cost. What we end up with needs to be something that someone with a home workshop person can reasonably fabricate. If that's doable, then it bodes well for the ultimate ability of a company with more resources to mass manufacture and roll out the technology. I can get some outside help from professionals with commercial / industrial machining and welding equipment, but the more I can do myself, the better.
Progress Tracking: Implement a system to monitor and track project progress. This can be as simple as a checklist or a more sophisticated project management tool. Regularly review and update the progress to ensure the project stays on track.
Lessons Learned: Encourage individuals to reflect on their projects and document lessons learned. This enables continuous improvement and knowledge sharing among team members.
Celebrate Success: Acknowledge and celebrate the successful completion of projects. This fosters a sense of achievement and motivation for future endeavors.

SpaceNut · 2023-06-18 08:47:03

I think if we look at this, we see that this is the discussion companion topic of a wiki that Kbd512 could create posting into the wiki the content of discussion so as to create this thermal battery concept further.

I see the first item as cheap to construct and use.

Raised earlier was the heat of 500c being close to passengers but with a proper enclosure and isolation, I think most of that is a non-problem until one of these batteries are punctured by an accident so that could be a problem. So large thermal batteries are going to need reenforcing to keep that from happening. The added mass also cuts into the efficiency of the vehicle. Were as a blade of less size than a 1m cube at about a ton is a better solution sure that effects range but keeps performance for cost to fill.

kbd512 · 2023-06-18 12:38:18

SpaceNut,

I've been very sick over the past several weeks, took a trip to the ER, did a lot of tests, and had a minor surgical procedure performed for gastrointestinal issues. That's why I haven't posted very often as of late. I'm doing better now, but recovery has been slow. I've lost about 15lbs because I wasn't able to eat much of anything for the past month or so.

Anyway...

Calliban indicated that checking high-strength welds on steel tubing containing high-pressures while exposed to exhaust manifold temperatures requires a Cobalt-60 source to check the quality of the welds to ensure that such a device doesn't explode. I think that's what will ultimately limit my ability to use hot limestone as a heat storage medium. The low cost of the limestone is immediately offset by the need to use expensive stainless steel and sophisticated weld verification techniques. A large automotive or aerospace or oil and gas company might have the resources and know-how to do that, but I don't.

After doing some searching, I then found a British-designed Stirling engine intended for air conditioning efficiency improvement, which has a 60% electrical-to-mechanical work conversion efficiency at the operating temperature ranges of normal refrigerants used in air conditioning. The device in question has Copper radiator fins attached to a piston pump driven by an electric motor to recover and use what would otherwise become waste heat. Those fins are dipped into a heat transfer medium (Silicone oil) to recover heat-generated pumping losses, helping to "drive" the piston. It seems to take some design elements (most notably the pistons with radiator fins attached to them to recover heat) from "prior art" that NASA and GM collaborated on, to produce a Stirling engine external combustion engine vehicle that was about 10% to 15% more efficient than the gasoline engines of the late 1970s / early 1980s. Since this device has already been designed to work well in the temperature range of almost-boiling water (home and automotive AC compressors get very hot), I think it's a good power transfer candidate for this project.

That's more or less "where I'm at" for this home-built thermal battery car. I'm going to fab a very large (almost 600 gallon total internal volume) hot water tank, it's going to be an integrated part of the chassis of the vehicle, it's going to be made from ordinary automotive sheet steel since that's what I can get a lot of for very little money, and the thermal power transfer loop will be a series of AC condenser cores, some of which are contained inside the tank to absorb heat from the hot water, with the other drawing in comparatively cold air from the atmosphere. If I use more or less standard AC components that the HVAC and automotive industries already mass-manufacture, however far from optimal they may be, then there's at least a chance that this vehicle will actually be built in quantity.

I intend to use R290 (Propane) refrigerant and microchannel radiator cores:

Kaltra Microchannel Condensers - Heat Exchangers for Condenser Applications

The combination of refrigerant and microchannel condenser cores are already rated for the application I intend to use them for. They're more commonly used in conjunction with flash evaporators, but can be pressed into service in this application. Max working pressure of Kaltra's high pressure condenser cores is 470psi, max operating temperature is 120C, and they're warrantied for a period of 5 years. I think that will suffice. This vehicle will require about as much steel as a heavy duty truck like a Ford F350, less Aluminum than a car with an all-Aluminum combustion engine, and it's propulsion system needs to be some form of hybrid that builds pneumatic or hydraulic pressure for acceleration. I'm still working out all the details, but I'm starting with the hot water tank design and learning as much as I can about HVAC systems.

SpaceNut · 2023-06-18 13:01:19

I do hope you are feeling better as any gut surgery is a long-haul event that solved the issue.

No worries on the mini project.

I was trying pull the concepts into a standard template.

It appears that lower temperature and water loop is providing sterling drive generating of power to the wheels.

https://en.wikipedia.org/wiki/Stirling_engine

https://www.stirlingengine.com/low-temperature/

https://sites.suffolk.edu/mmartinb/2014 … ing-engine

SpaceNut · 2023-06-18 17:51:11

Here are some lower tier solar thermal energy to electrical out systems

Organic Rankine Cycle Integration and Optimization for High Efficiency CHP Genset Systems

https://archive.epa.gov/ncer/publicatio … esotho.pdf

https://pangea.stanford.edu/ERE/db/GeoC … jwalia.pdf

http://web.mit.edu/hemond/www/docs/perf … zation.pdf

https://orbi.uliege.be/bitstream/2268/2 … -Orosz.pdf

kbd512 · 2023-06-19 12:51:11

The 1.5 billion or so personal motor vehicles contain around 2.7 trillion metric tons of processed materials. If we mass-manufacture hot water powered vehicles, then we'll need approximately 5.4 trillion metric tons of materials. Most of that added weight will be steel and Aluminum alloys, but demand for raw materials will approximately double nonetheless.

If we presume we can obtain 50 to 100 miles of range per 500 gallon / 1,890kg tank of hot water (99C to 38C in summer or 99C to 22C in winter), and the Sun provides an average of 3 to 5kWh/m^2/day (best case and worst case for much of North and South America), and we assume worst case scenario since cars still have to run in the winter, and our total input heat energy efficiency is 75% (Aluminum coated steel reflector can thermalize about 90% of the incoming photon radiation from the Sun), then the size of the solar thermal array per 500 million cars is...

Summer Day Scenario:
99C - 38C = 61C
61 * 4,184J/kg·°C = 255,224J/kg
255,224J/kg * 1,890kg = 482,373,360J
482,373,360J / 3,600J/1Wh = 133,992.6Wh
133,992.6Wh / 4,000Wh/m^2 = 33.49815m^2 (at 100% photon thermalization efficiency)
33.49815 / 0.75 = 44.6642m^2 per car per day in summer (taking transmission and pumping losses into account)
44.6642m^2 * 500,000,000 = 22,332,100,000m^2 = 22,332.1km^2 = 8,622.5mi^2 (summer)
37,586,266,667m^2 = 37,586.3km^2 = 14,512.2mi^2 (winter)

The array will thus cover a land area approximately equal to South Carolina, with the understanding that approximately double the land area claim is required to avoid shading panels, roads are required for installation, more hot water storage and distribution infrastructure is required, etc.

According to the solar insolation maps of the US from NREL, a "winter day" scenario loses 25% of the input power, but that 25% loss roughly doubles the required collector surface area to heat the water back up to a consistent temperature. You must add 322,168J of energy per kg of water to go from 22C to 99C (169,138.2Wh for 1,890kg of water). That means 56.3794m^2 at 100% efficiency, or 75.1725m^2 at 75% efficiency. Appropriately sizing the collector surface is not "optional", either. To get consistent performance from a water powered car using a refrigerant loop, you need to heat to 99C and then finish at atmospheric temperature. You get more range during the winter than the summer, but you roughly double the collector area. There is no effective "power storage" option here, either. Your collector area must be sized for expected average throughput rate, regardless of seasonality.

If we had a singular perfectly square solar thermal collector array for powering 500M cars, then it would be a 149.44km per side. In reality, you need about twice as much land area to avoid shading panels. The required land area distribution will obviously not be "even" amongst the various states, this represents a total land area claim of 893.3km^2 / 344.9mi^2 per state in summer or 751.7km^2 / 580.5mi^2 in winter. We will also require a highly developed hot water pumping network to deliver the heated water to homes or service stations, of which there are approximately 145,000 service stations selling fuels across the entire US.

Given that these new vehicles will only go 100 miles at most, it's a certainty that a more extensive distribution network will be required. The new fuel product (distilled hot water) is very easy to store and should be completely non-toxic, but distribution must be factored-in to this new energy approach which has to throughput 250 billion gallons per day if all 500 million drivers travel 50 miles per day. US DoT statistics says the average driver travels about 37 miles per day. America presently uses about 322 billion gallons per day for all uses, so this is approximately doubling the capacity of the existing water distribution network, all of which requires new-build pipelines and storage tanks. We consume 369 millon gallons of hydrocarbon fuels per day, so hot water at 99C would require 677.5 times more volumetric throughput. Them's the breaks for choosing to pursue a truly renewable low energy density system. The upside is little to no toxicity, a hot water spill is a minor annoyance, and the total amount of energy sloshing around in the distribution system is roughly equal to what hydrocarbon fuels must otherwise provide. Incidentally, CPVC and PEX water pipes last for 70 to 100 years, so that's about how long a hot water distribution network should be expected to last before requiring complete replacement. We will either pay the piper up-front for this kind of system, or pay more over the long-term to synthesize hydrocarbon fuels and create electro-chemical batteries (if there was enough material on Earth or somewhere else to do that, which there isn't at the present time).

It should be noted that this doesn't completely replace hydrocarbon fuels, either, but it reduces the need to continually find more of them. We still need plastics, steel, concrete, and refrigerants to use for this sort of system to work. There is no such thing as oil refining without producing a lot of gasoline and diesel, for example, even if all you actually wanted was plastics / rubber precursors and tar for asphalt. I sincerely doubt we're going to dump the gasoline into the street the way we did before gasoline powered internal combustion engines existed. The amount of natural gas and diesel required to produce all the steel and concrete will still be as high as it ever was while manufacturing the first generation of technology, even if recycling is drastically easier with this solution than with electro-chemical batteries.

Now let's estimate the steel consumption required...

If we assume that each square meter of solar array equates to a 4mm thick steel plate (2mm thick Aluminum hot-dipped steel collector / concentrator mirror and a tubular steel support structure underneath it), then 31.4kg/m^2, so 22,332,100,000m^2 * 31.4kg = 701,227,940,000kg = 701,227,940t (summer use case) or 1,180,208,773t (winter use case). US steel production is around 100Mt per year, so construction of the solar thermal array is a 12 year project on its own, assuming no steel is consumed for other construction purposes.

500M cars containing 2t / 2,000kg of steel per vehicle is 1Gt of steel. Total global steel production is about 1.875Gt per year. That means replacing the entire fleet of 1.5B personal cars requires 3Gt of steel. At present, there are only 278M registered vehicles in the US, but the "grand plan" is to phase out hydrocarbon fuels, so the estimates given are for 1/3rd replacement of the global fleet, which accounts for a whole 2.67% of total global greenhouse gas emissions. Based upon the numbers, the 500M figure roughly accounts for the the total number of cars in the Americas.

We're not going to run short of steel, but we need to think about whether we use automotive HSLA steels (CorTen / A242 / others like HY80 or similarly strong steels) vs A36 and A1011. We could potentially use twice as much steel that's 50% to 100% cheaper, or half as much steel that's 50% to 100% more expensive, since HSLAs contain more rare / high-demand alloying metals. The more expensive steels could offer more range by removing a substantial amount of vehicle weight. The steel alone will cost about 3.46 trillion dollars, assuming the use of cheap hot-rolled A36 / A1011.

Extrapolating out, 10.38 trillion dollars for the steel alone, in order to reduce greenhouse gas emissions by less than 8%. Who knows what the actual manufactured products will cost, but 50 trillion dollars or more is not an unreasonable estimate. This is why we haven't already phased out hydrocarbon fuels. The alternatives are extremely expensive and do very little to reduce consumption.

We're going to completely run out of battery and electrical conductor metals long before we ever convert all passenger vehicles over to using electro-chemical batteries, so if someone here has better ideas, I'd love to know what those are.

Terraformer · 2023-06-19 13:04:43

We're going to completely run out of battery and electrical conductor metals long before we ever convert all passenger vehicles over to using electro-chemical batteries, so if someone here has better ideas, I'd love to know what those are.

I'd say "drive less", but...

For personal vehicles, how much range is actually needed under its own power? For long distance travel, there's no reason a train can't be used to ferry them. Or even medium.

Power needed is a function of speed. Most people could probably get a velocar up to 20mph? So if that's fast enough for the personal vehicle you want, it's far simpler to build velocars.

Last edited by Terraformer (2023-06-19 13:19:05)

SpaceNut · 2023-06-19 14:42:48

The velocar technology can use a regular 12v battery and modified generator capable of recharging the battery while you pedal. A few solar panels on the roof would top off the battery while idle. All of this is in the bikes for mars topic.

Back to the heavy amount of water that is extreme when compared to a 11 gallon tank of limestone or sand or granite dust ect that is heated to 500 'F which is in the range of an electric oven element to recharge the sand. Even a few solar panels of the roof can keep it topped off while parked. Plug the elements into a timed outlet at night to get the box of media hot before getting up in the morning and use it daily for commuting.

At this temperature we are back down into no special material requirements a temperature difference of 300 'F to make use of before the battery is browning out.

The documents for the solar MIT unit do give the power levels we can expect as well as pressure levels for a heated AC gas mixture that would pass through the hot media.

We do need electrical for night and other uses so it should not be that big of a deal to se an electric storage system that is reasonable for this energy sized vehicle.

So will that volume of heated sand contain 4 gallons of gasolines electrical heat equivalent in the 500 'F tank max temperature. As that is enough for the daily commute and if that energy is less than the price of the gas, we have already succeeded.

kbd512 · 2023-06-19 16:35:20

Terraformer,

Ah, yes, ye olde "I don't see any value in personal transportation, so nobody else should, either." I can pay $20,000 for a very good car and live away from most of our leftists, who never fail to make the cities that they inhabit unlivable, or I can pay $1,000,000 to $2,000,000 for the privilege of suffering their brain-dead nonsense 24/7/365. But hey, at least then I can get mugged walking to work. Maybe I can take my kids to see naked men twerking on city buses or drug addicts shooting up for entertainment. So back in reality-land, bane of leftists the world over, I'll take the problems and costs associated with living with cars over living with leftists every day of the week.

SpaceNut,

11 US gallons of limestone weighs 104kg. Using the temperature parameters you provided (260C to 189C), you have 3,207Wh of total energy storage to work with. At 60% efficiency, you have 1,924.2Wh (18.5Wh/kg) of usable energy. We may as well use Lead-acid batteries, since those are about 50Wh/kg to 100Wh/kg, or 38.5kg for the same energy storage. Why didn't we start making electric vehicles using Lead-acid batteries? Oh, right, we already tried that and it was never going to work well enough to be viable at the scale required. Gonna hold onto that hot power brick and keep it insulated? That'll surely add extra weight. Assume a 100kg rider of this vehicle. Now we're up to 204kg before adding any weight for the vehicle itself. That's about as heavy as a full-size Honda motorcycle, which you won't be pedaling anywhere. If this vehicle weighs in at 275kg total weight including the rider, then it's as heavy as most types of Harley-Davidsons. Are we constructing this vehicle from more super-expensive materials we'll never get enough of, for some marginal weight decrease that does little to extend the range?

If you're going to get to work at walking speeds, then as Terraformer suggested, you may as well walk or ride a bike. It's been about 38C here for the past week and the heat index is 46C due to humidity. That's a fairly typical June / July / August / September / October here in Houston. I would first like to see if you or Terraformer can ride or walk 25 miles in that kind of heat without keeling over, because that's how far my wife has to drive to work, but I'm pretty sure I already know what the both of you will do when confronted with reality. It's even further than that to our doctors offices, so even less practical.

Once again, the average American driver travels about 37 miles per day. I'm illustrating the limits of actual renewable energy, and nobody here seems to like the implications, but you have to sacrifice something. I'm willing to give up on hydrocarbon fuels and unlimited driving range if our leftists are willing to give up on their dead-before-arrival electric-everything fantasies that completely ignore materials scarcity and environmental damage in favor of a Jetsons cartoon way of life that Earth simply can't support.

SpaceNut · 2023-06-19 16:59:41

I had thought that the battery would be better than the W = C * 1.16194 to heat 1 kilogram of water in 1 hour by 1 degree times the number of gallons to liters of water since that is 4.3 x 11 = 47.3 Liters. Water as 260'C is 302.1044 watts and tank holds 47.3 Liters for 14,289.5 w of tank capacity.
So why is the limestone so poor or was that the mystery of the higher temperature?

https://en.wikipedia.org/wiki/Table_of_ … capacities

https://www.engineeringtoolbox.com/sens … _1217.html

Maybe a different material can be used?
https://material-properties.org/granite … ductivity/

original

A 1m sphere of limestone would weigh 1.4 tonnes. Heated to 520°C, it would store some 194kWh of heat. It would take 124 hours for the sphere to lose 1% of its heat by conduction.

1/10 scale of 260 C should yield 9.7 kwh for a period of 6 hrs so what happened?

granted it is not the much higher level for the 20kw motor but I was targeting 10kw max. and even at 60% that is still 6kwh of power.

Calliban · 2023-06-20 02:21:31

kbd512 wrote:

I've been very sick over the past several weeks, took a trip to the ER, did a lot of tests, and had a minor surgical procedure performed for gastrointestinal issues. That's why I haven't posted very often as of late. I'm doing better now, but recovery has been slow. I've lost about 15lbs because I wasn't able to eat much of anything for the past month or so.

Hope you get well soon.

Terraformer · 2023-06-20 02:34:55

kbd,

Ah yes, the "I am so addicted to personal transportation it's the end of civilisation if I don't have a car". It's not the end of the world if people have to take the train. One thing that we have in abundance is people to hire to patrol the trains and remove those causing problems. Cheaper than batteries. Cars post-oil are a very expensive way to fix a fairly simple social problem, and wouldn't a private rail line be able to impose better terms of carriage on its customers, and enforce them?

kbd512 · 2023-06-20 05:06:08

Terraformer,

I guess it shouldn't surprise me that you think an energy and technology problem will be solved by reinventing society without serious thought given to how much money and energy that would cost. Seriously, though, the Democrats who run virtually all of the major cities in America do their level best to assure that social problems exist into perpetuity. Their voters haven't figured out that they never intend to deliver on half the stuff they promise and ignore all real problems until it threatens their political power. If there aren't enough real problems to refrain from solving, then they invent new problems to avert the general public's scrutiny while they rob them blind. Some of us are smart enough to get as far away from them as we can, because we're not interested in living in demented clown world, so we can leave them to their own devices.

Ask some Californians when, if ever, they're getting their new "light rail" lines completed. I'll be dead and gone before that happens. As far as private rail lines are concerned, they run afoul of the same NIMBY, NIH, and political problems as public rail lines. Billions have been spent and nothing has been built. The same applies here in Texas. We're still waiting on our Houston-to-Dallas light rail project. Both have been 20+ year circle jerks. When a new road is promised, most of the time it actually gets built. That's why we have so many roads. Nobody consulted you or I on this, but they actually did it, so in my view something is better than nothing, even if it disagrees with some part of how you or I think society should be organized.

As far as "post-oil" is concerned, there is no such thing. That's no different than "post-steel". Post-steel is the same thing as saying, "I want to go back to the Stone Age" or "Beyond Thunderdome". Well, good for you, but almost nobody else shares your beliefs, so that's not happening without some sort of external forcing function mandating that it happens. You're using a computer to reply back to me. That was made with petroleum products and is powered by petroleum products. We're at where we're at. Regressing backwards in time or completely reinventing society is unappealing to most people who are not fixated on achieving specific outcomes they think are desirable because they're willing to totally ignore all other aspects of their proposed solution that most others would find unacceptable.

During my last visit to Chicago, I sat on the train next to a young man who told me he was so high he couldn't remember where his phone was. I helped him look for it for about 5 minutes before realizing that it was never there to begin with. If traveling in my own private car means I don't get my half hour of "quality time" with drug addicts, hookers, and street thugs, then I guess you'll just have to believe me when I say that I won't lose any sleep over having to figure out how to keep cars running. If that same car causes other people to loose some of their sleep, then so much the better. They'd do well to remember that the next time they vote for someone who doesn't solve those social problems, but spends all the money available to do whatever money can do while not actually solving any real problems.

Terraformer · 2023-06-20 06:13:49

kbd,

You Democrats are all the same. "Oh no we can't enforce fare evasion rules and police public transport, we need to spend trillions on an alternative". Nevermind the fact that other countries manage it. Nevermind the fact that Asia and Europe don't seem to have those problems. Actually having law and order is far beyond the meager abilities of the American. It shouldn't surprise me that you think the existence of police is "reinventing society with no thought to how much it would cost".

tahanson43206 · 2023-06-20 06:28:31

This topic was supposed to be about storing thermal energy in limestone.

We seem to be branching to Chat topic territory.

My impression from following along is that the tradeoff between mass and energy for the thermal energy solution is looking less and less attractive.

That glowing hot ton of limestone in a vacuum jar in the back seat is hard to get out of mind.

That's where SpaceNut is wanting the limestone, if I understand posts correctly.

(th)

Terraformer · 2023-06-20 06:42:03

Anyhow, fairgrounds solved the problem of powering electric vehicle decades ago. They're going to be restricted to roads anyway; why not put an electrified wire overhead and draw power from that? Few people will be travelling more than a few miles from a main road.

tahanson43206 · 2023-06-20 09:05:24

For Terraformer re #97

Your ideas are worth development. I have created a topic for the theme you have introduced.

http://newmars.com/forums/viewtopic.php?id=10528

Please confine future comments in this topic to the use of thermal energy to power vehicles.

The topic title does not exclude multi-person vehicles such as buses in regular service along prescribed routes.

If you want to focus on public bus transportation, please use thermal energy to power your design, while posting in this topic.

I am personally quite interested in seeing what you might be able to come up with.

(th)

kbd512 · 2023-06-20 09:50:14

tahanson43206,

This topic was always intended to be about thermal batteries for cars and stationary energy storage, but as always we devolved into the quaint but grossly unrealistic idea of fundamentally transforming a society into a series of mega cities with light rail. It's as if some here think I've never lived and worked in such places before, except that I have, over a period of about 10 years (Chicago, Los Angeles, and now Houston). If it was "just me", meaning I had no wife or children, then maybe I would still be living that way. After you have children, you start thinking a lot more about what you want them exposed to on a daily basis. I don't find the degeneracy of living in a large densely populated city particularly appealing. I would've taken no issue with living in Tokyo, but since I met a Vietnamese woman who was living in Texas, that wasn't a realistic option. I used the trains all the time in Chicago, New York, and of course, when I was living in Japan. I think they're great, and of course, they already existed when I lived there, which is their best quality. Real cars / trucks / trains are always the best kind for actually using. The notional ones are only ever worth the paper they're printed on. Funny that.

Living in Chicago or San Francisco or even Houston is nothing like living in Tokyo, though. There are no bleeding hearts in Tokyo. You screw with the Police in Japan, they beat the crap out of you and haul you off to jail, simple as that. You can whine and scream "racism" all you want, but it won't change how Japanese society views law and order. The people who live in our cities permanently voted that sort of nonsense into existence. It's not my job to convince them to change, and in point of fact they're not going to change. I did the only half-way intelligent thing I could, which was to decide to seek out a better life elsewhere. That means living out in the suburbs, as so many Americans already do. At the same time, I'm trying to adequately resolve an energy problem here that's "baked-in" to all low energy density systems. I'm doing that by deliberately choosing highly abundant and low-embodied-energy materials, but "the catch" is that you need a lot of them, and in the quantities required they're not all that cheap. Regardless of what the non-hydrocabon energy solution to transportation looks like, it resolves 8% of the total emissions problem if every car, truck, bus, train, and plane on planet Earth uses some other kind of "fuel" or energy. Since cars / trucks / trains / ships represent the lion's share of transportation energy consumption, knocking out what we actually can in a practical manner is the most obvious "first step".

We already tried batteries. We were short of suitable battery making materials when industrialization started and we're short of those materials now. Demand increased, but investment into increasing supply hasn't increased during the past 10 to 20 years, about the same as oil. Apart from improved energy density, which is great, nothing substantive has changed from the early 1900s to the present day, apart from how short we are of hydrocarbon energy. All metals were more abundant and accessible back then than they are now, and the energy input into mining was a fraction of what it is today, on account of total throughput required and grinding size required for profitable ore extraction. As Professor Michaux points out, the last major advances in metals extraction came during the 1920s when modern flotation processes were invented to remove the ores from the rock.

Such a starting point as may have existed 75 years ago does not exist now. Europe isn't all that different than America, seeing as how there are almost as many cars in Europe as in America. Modern America and Europe were both built on a system of roadways. The railways haven't held primacy since WWII, for any nations with enough material wealth to fully industrialize and urbanize. Was that a "great idea"? It was / is clearly less than ideal without abundant energy, but this is where we are right now. I don't discount Terraformer's point, but there's no way to retroactively change the type of solution without costing even more money. Austin's light rail solution now costs $978M per mile. Texas can purchase 5 new GW-class nuclear reactors for what a single city's low ridership rail solution will ultimately cost the taxpayers. Meanwhile, TxDoT pays $30M to $60M per mile of new highway. That is why we see new roadways being built all the time in Austin, but very little rail. I trade in energy and transport solutions to the present situation on the ground, not what I'd rather have if I had a time machine to travel backwards in time to "undo" the past 75 years of industrialization and urbanization.

Pissing and moaning about the cost of maintaining what we already have is waste of time and energy. I showed what the cost of total replacement is for the energy system to power the existing fleet of cars, without using non-recyclable materials or attempt to mine for materials that simply don't exist in sufficient quantity. Nobody likes the price tag, but that's the true cost of total replacement using hot-rolled A36 steel, which is the cheapest type of material available in the quantities required to get the job done in a meaningful period of time (less than a human lifetime). You'll need a lot less steel if you use nuclear power, which provides electricity in addition to waste heat, but again, politics and NIMBY culture are real phenomenon. Our Democrats do their utmost to ensure that no new nuclear reactors are built, and I don't feel like fighting them on that point (not because I think that they know better, but because you can't fix stupid), so a land area the size of South Carolina is required to "go solar" when it comes to powering cars. This land area claim is split between Canada, the US, Mexico, South and Central America, so less of a space claim to individual nations comprising the Americas. Again, the places we'll put these arrays, I doubt anyone will know that they're even there unless they go looking for them.

This proposed change will have a meaningful 2.5%+ impact on total global CO2 emissions, so whining about costs aside, that's a material change in the correct direction, rather than simply offshoring CO2 emissions to China to make photovoltaic panels using otherwise stranded coal assets, as Calliban pointed out. It's also a "semi-permanent" solution, meaning the energy input system will last for at least a human lifetime without significant replacement. Whenever replacement time finally rolls around, it's 100% recyclable, by intentional design. Beyond that, it also creates real organic economic growth for blue collar working class people who are the "Salt of the Earth", in my opinion. The rich people can still play with their electronic toys, since this solution doesn't detract from their ability to live the Jetsons lifestyle.

The thing I find most perplexing is why some of us don't seem to want abundant energy and material wealth. Everything outside of their specific lifestyle is viewed as excessive or abusive in some way. I don't use X / Y / Z, therefore nobody else should, either, or they need to be penalized for doing so. What is so wrong with creating material wealth for the average person? So long as it's truly sustainable and indefinitely maintainable, as this solution is designed to be, who in their right mind doesn't want that for everyone? Think you'll have to worry about a lot of street crime when most people can truly afford a fairly affluent lifestyle? I don't. Only the merchants of despair think otherwise. What have they contributed to civilized society, besides misery and suffering?

Now, back to our regularly scheduled program of workable solutions...

We're talking about an additional fresh water reserve of approximately 750 billion gallons for the global fleet of personal motorized vehicles, or a bit less than 3 cubic kilometers. Some will inevitably lost ot evaporation, but most of it will stay within this new system, which will still be sealed like any other fuel / energy storage system. It's closed-loop. Nobody will notice that the water is missing. The US alone consumes 322 billion gallons per day. We will take the water from the ocean to lower the sea level, since some of us are so concerned about that. This giant new solar thermal system will have the ability to flash-evaporate enormous quantities of sea water and supply enormous quantities of thermal power for home appliances, in lieu of an ever-increasing and ultimately unsustainable demand for electricity. You need electricity for lights and electronics and some kinds of power tools, but if that was all that required electricity, then there are truly huge energy and emissions savings to be had using pure thermal power systems sourcing energy from sunlight or direct mechanical wind power. The bigger we build this system, the more energy on tap for on-demand uses, and the less incredibly precise voltage / amperage / sine wave manipulation required for stabilizing AC electrical power. Like many things, what appears superficially inefficient is actually the exact opposite in operation / maintenance / storage / recycling.

The 50 to 100 miles of range that you get from a hot water car the same weight / size class as a large SUV is plenty for the type of driving most people clearly do everyday. With sufficient service station capacity, supplying the hot water is not a significant problem. The people have clearly spoken, with regards to cars vs trucks. They prefer trucks and SUVs. Rather than assert that they're all wrong because I take issue with cars in general, I'm going to accept their decision and construct a vehicle that performs similarly, albeit over short ranges, that has the ability to haul around 4 to 6 people, regardless of how its actually used, but with drastically reduced emissions (essentially nothing but minor amounts of hot water evaporation after it's built). My goal is to get them to the point of actually driving new vehicles that are less expensive to produce, so more can be made and sold, and very simple / easy / low-cost to maintain.

Weighing the pros and cons of roads vs railways vs cable cars vs barges is another problem for another person to solve in another thread. We have the roads right now, and they're going to be used one way or another because they actually exist. If you want people to start driving cars that don't produce CO2 or other noxious fumes or spontaneously combust from poor battery build quality, then solve the problem of making the entire solution affordable enough for the majority of car owners to buy into. You have to zoom way out, you have to relinquish personal preferences, and you have to make tough calls on the overall affordability of better materials or more efficient methods of operation vs total cost to own and operate.

tahanson43206 · 2023-06-20 10:10:15

For kbd512 re #99

It's good to see this topic back on track!

Lest anyone has overlooked it, I am the only person in this forum who has made an investment of any kind whatsoever in an attempt to help to translate this topic from vision to reality.

I have on had one brand new 12 volt motor generator designed (I think) for golf cart service. I believe will serve admirably as a device to translate thermal energy into electric current. Next month, as budget allows, I'm planning to invest in a digital meter designed for automobile service. This particular meter will show current as well as voltage, and possibly actual work accomplished, although I'll have to wait to see if that is the case.

SpaceNut and I have worked out a concept for a load of 100 watts at 12 VDC, or about 9 Amps.

I am willing to invest in a $32 air motor drill, which should be able to power the motor generator.

That device needs 7 cfm of gas (air or whatever you and Calliban come up with).

I'm counting on you and Calliban moving slowly but surely toward a shared vision of how members of this forum can translate the vision into gas flowing at 7 cfm for some period of time.

At this point, I don't care if the time is only one second. It is the proof of concept I'm after.

(th)

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#76 2023-06-16 19:23:51

Re: Limestone-based Thermal Battery

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