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Calliban,
At least 50% of the people in America are leftists of one stripe or another. EVs have achieved 1% of market saturation and now they can't sell the remaining EVs in the new car lots, regardless of discounts offered, to achieve 2% market saturation. Now we know what the real EV market is. It always was 1% to perhaps 2% of car owners who think turning planet Earth into a toxic electronics waste dump was a good idea.
Everyone voted with their wallet by simply "not buying EVs". The other 49% of leftist / Democrat voters, all voted to stuff this EV trash right up the rear ends of their fellow "basic math deniers" / "climate changers" pushing this non-workable idea, which was falsely touted as "saving the planet". The leftist business owners pushing the faddish "green energy" agenda never cared about the planet, only making another quick buck off of producing more toxic electronic trash- a "super-sized" version of cell phones- 95% of which have never been recycled and never will be recycled. Leftist politicos wanted to use electric grids to "control" the ability of their own voters to move about their own country. I'm guessing they all saw what happened in California under Governor Newsom. Buy an EV- oh, wait, don't even think about charging it because our electric grid can't handle it.
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On the plus side, the failure of EVs may encourage people to think more carefully about which technology options are possible, given resource and capital constraints.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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Here is something for wind haters to hate on: https://www.msn.com/en-us/money/technol … 217f&ei=51
Quote:
Bill Gates backs innovative wind energy alternative:
Internal server error of course so I cannot complete the quote.
Truth and Trust? I don't know. Someone says that Bill Gates likes it.
But certainly, it is different.
Done
Last edited by Void (2023-11-09 07:54:09)
End
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Here is something for wind haters to hate on: https://www.msn.com/en-us/money/technol … 217f&ei=51
Quote:Bill Gates backs innovative wind energy alternative:
Internal server error of course so I cannot complete the quote.
Truth and Trust? I don't know. Someone says that Bill Gates likes it.
But certainly, it is different.
Done
A wind driven fence. Interesting and worth exploring. This could have applications for offgrid power. Where I live in northern England, you need planning permission to build anything and rules are tight, especially in national parks. If I wanted to build a wind turbine for home power generation, they would likely turn me down flat. But something that can be disguised as a fence is likely to be acceptable. It is easy to forget that individual inventions do not need to solve every problem. Niche solutions can be valuable in their context.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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Void,
This is the type of innovation that we need, assuming it actually works, and I hope that it does. Any 2.5MWe device that can fit on 1 semi truck is the sort of energy tech that stands a better than average chance of being technologically and economically viable. I wish Airloom Energy and Bill Gates good luck on this project.
My opposition to present generation of wind turbine energy technology is the math, physics, and monetary cost involved. The current devices are the size of small skyscrapers and mount a trio of airliner-sized wings. Some of them have blades / wings much larger than any airliner's wingspan. If building airliners that large isn't practical, then what does that say about energy generating devices with wings that are subjected to g-loads sufficient to fold up any fighter jet's wings like a pretzel? The mere fact that they can last 10 to 20 years is astonishing. Since the capacity factor is 33% or so, what that actually means is that a set of well-made blades is good for less than 7 years of continuous operations, at most. Unfortunately, the waste generated when gravity inevitably breaks those blades is quite extreme. It's not sustainable.
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The centrifugal forces acting on a cross sectional element of a blade are proportional to the square of rotation rate and directly proportional to radius. At constant rotation rate, an element twice as far from the hub, will experience twice the force. But elements closest to the hub must support the integral of all forces imposed on all elements out to the tip. So longer blades induce higher stresses at the hub, unless rotation rates are relaxed. So large blades require carbon fibre epoxy composites and materials strength limits the length of blades unless rotation rate is reduced.
https://www.intechopen.com/chapters/51202
But that doesn't appear to be the thing that most limits blade life. It appears to be a combination of gusts and vortex shedding, with introduce vibration. This leads to fatigue and the failure of glue in laminates, especially at coupling points close to the hub. Vibration results in shearing stresses which seperate layers and lead to wear around bolt couplings. Not an easy problem to solve. A simpler solution like wind fence may turn out to be more sustainable. But vibration is an endemic problem for all wind machines because of gusts.
Last edited by Calliban (2023-11-09 16:41:08)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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Copper Market Slump Threatens Shift to Wind Power, Electric Cars
Some can choose a smaller vehicle of course These Sub-$1000 Electric Bikes Prove That E-Biking Can Be Affordable
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SpaceNut,
It's almost as if there are insurmountable physical resource limitations preventing this fanciful transition to electric-everything. The solution to the transportation problem is not scooters and bicycles. In a world with fewer workers, simplified supply chains, and reduced material and energy inputs, the entire energy and transportation technology set associated with electricity and electronics is completely wrong and thoroughly counter-productive. That last MSN article you posted lamented the fact that America doesn't use any more electricity today than we did in 1965. There's a simple reason for that. Increasing demand to any significant degree immediately runs afoul of basic material resource limitations. Remarkably, nothing about 2025 America uses dramatically more or less energy than 1965 America. Efficiency improvements allowed us to remain "frozen in time", with respect to electrical energy consumption, despite doubling the population.
Electricity and electronics are a shiny new object of affection for people who lack basic math skills. The entire notion that a Rube Goldberg machine (wind turbines, photovoltaic panels, grid scale energy storage and interconnects spanning continents, electric cars, batteries, and computers) could consume less energy and less materials, whilst supplying equivalent energy as the most calorifically dense hydrocarbon and nuclear fuels known to humanity, is an outright absurdity. How the peddlers of this flagrant nonsense managed to convince so many people that the opposite was true, is beyond my understanding. I think a lot of people were indoctrinated rather than educated.
The wind and sunlight are renewable, durable, and sustainable. Electrical and electronic machines are not. The universe is very unkind to them in ways that make them unsuitable replacements for providing energy or mass transportation. Mechanical devices still fail, but typically not in ways that make them completely unusable without going all the way back to raw molten metal. There is no equivalent of "thoroughly clean the device and replace the seals" for a battery or electric motor or photovoltaic panel, as compared to an internal combustion engine.
I can clean the photovoltaic panels that power the yard lights my wife purchased, but both the panel and its small battery are dead and will remain completely non-functional until the process that was used to create them is repeated. For devices that were supposed to last 5 years, almost all of them were dead inside of 2 years. For repairing the gasoline engine in my car, cleaning and replacing the seals fixed the problem. I simply cannot do anything like that using this new electrical and electronic technology, which works perfectly until it fails completely- a process that might happen the day it leaves the factory or 5 years later.
We can achieve this cleaner / greener world that some of you want so badly, but not by creating more electrical and electronic machines.
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The majority of greens are happy to perpetuate this idealism because they are ignorant of the technical details. The sort of people that are drawn to left-wing green movements, tend not to be scientists, engineers or technologists. And they tend to assume that there are simple technological fixes that will allow current lifestyles to continue on low power density, intermittent energy sources. They assume this because they have seen technology do amazing things in the past and are ignorant of the energy dynamic behind it. They are incapable of doing the maths. They are technologically illiterate people.
We have all spent a lot of time exploring the options for energy transition on this board. What I have seen tells me that a society living on wind and solar energy sources will require deep changes that most people advocating for energy transition are not prepared for and probably cannot imagine. Transportation will be slower and more erratic. Work of all kinds will need to adapt to an intermittent energy supply. That will be tough for most people. When it is windy, they will be working 18 hour days, probably back to back. When it is not windy, they will be taking unpaid leave, whether they want to or not. This sort of working arrangement is convenient to no one and requires substantial changes to the social contract and working conditions. But it is also unavoidable if the energy transition is based upon intermittent renewables. Storing large amounts of mechanical and electrical energy is impractical. Working patterns must adapt to use energy when it is available and stop using it when it isn't. That holds true for all functions using electricity and mechanical power. There will be times when it isn't available. That means your working hours will depend on the weather. If you advocate for a renewable energy future then you are advocating an intermittent lifestyle. If the people advocating for a green energy future can stick to that lifestyle for more than a few weeks, I would be very impressed. There are no easy and cheap technological fixes to this problem. It is the price that must paid if you want to live on renewable energy.
Many functions that we consider to be private and family based, will become communal and centralised. Cooking using stored solar heat will need to be centralised, with a single large cookhouse supplying the needs of a town. In this way, we can use heat gathered in the summer to cook food year round. But the physics of heat transfer mean that this can only be done on a large scale. Bathing will be the same. Rather than every house having wash facilities, a town will have a centralised bath house attached to an interseasonal heat store. Most towns will not be able to afford district heating. But a town can be provided with a heated sitting room, that also functions as a library, with a cafe. This would be attached to an interseasonal heat store. In winter, most people would spend a lot of time here, as most houses will not be heated. The town cook house would be served by a large underground freezer, with a heat pump directly powered by a mechanical wind turbine. Clothes washing would be served by a laundrette, which is built close to the town heat store and is provided with mechanical power from the wind.
The town itself would be surrounded by factories. People working in these factories will be on call and would be expected to adjust their working hours on short notice depending on weather conditions. People will hate that. But it is a consequence of living on intermittent energy. It does seem like a high price to pay for not using nuclear power.
Last edited by Calliban (2023-11-12 17:42:51)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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Interest rates have returned to historical averages and QE has stopped. Many sectors that grew up during the post-2008 ZIRP period are being shown to be uncompetitive. Unfortunately that includes the EV industry.
https://oilprice.com/Energy/Energy-Gene … r-Car.html
Lucid motors is losing almost a quarter of a million dollars on every car it sells. In my opinion, the collapse of this industry cannot come soon enough. Once its failure is complete and undeniable, the world can start talking about solutions that might actually work in cutting fossil fuel use. In the transportation sector, this could involve an extension of the national rail network to allow freight to be delivered to within 10 miles of any town. Redevelopment of inland waterways also holds promiss. These options are more likely to succeed than road BEVs, because unlike BEVs they actually improve energy efficiency and have lower energy and material resource needs than road transportation.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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This is interesting, although the author get the physics completey wrong.
https://oilprice.com/Latest-Energy-News … nergy.html
The downdraft tower is a long, vertical hollow tube. It would be built in places with high insolation, with high ambient air temperature. Water is sprayed in fine droplets at the top on the tower. This cools the air, increasing its density. The colder, denser air falls down inside of the tube at speeds reaching 50mph. A compact air turbine is located at the bottom of the tower. Air turns the turbine and escapes through horizontal vents at the bottom.
Pros:
(1) Aside from the compact turbine and the water pump, the system has no moving parts. It is a hollow steel tube, held in position by bracing cables. It should have a long working life, which boosts EROI.
(2) A constant 50mph wind allows the turbine to achieve a relatively high power density. This is beneficial to economics and net energy return.
Cons:
(1) This system works best in hot, dry areas like deserts. These places tend to be far from demand centres and tend to be short of water.
(2) Salt water could be used if the tower is close to the coast. But salt introduces corrosion problems and salt buildup on the land causes other problems.
(3) The tower needs to be tall to achieve high power output at the turbine. Wind loads will introduce fatigue issues that will limit tower life and require regular replacement of bracing cables, which must be stainless steel.
(4) Power output is a function of ambient air temperature and humidity, both of which vary across the seasons.
Verdict: This concept is interesting and may have applications in specific areas. But problems associated with fatigue, water availability and its limited applicability beyond desert areas tend to limit its applications. But in places like Texas, California and New Mexico, this could have applications. The best option would be to take advantage of natural features like hills and mountains to carry the downdraft tube. This avoids fatigue life problems and allows the tube to be made from concrete, which is a cheaper material.
Last edited by Calliban (2023-11-15 11:05:40)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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For Calliban re the link to an oilprice.com article ...
My impression has generally been favorable toward the quality of the work published by this site. However, there was clearly NO editorial input into that article.
Or perhaps the editors are as befuddled as the writer.
This forum has a long history. Somewhere in the archive is a discussion about the opposite concept ... a tube running up a hill to take in solar energy and heat a flow of air, so that there is a constant flow at the bottom of the tube. This is the concept (or rather physics) that allows sail planes to navigate from one thermal column to another.
Heated air has a tendency to rise because it displaces more volume, and colder denser air flows in underneath.
If you happen to run across a more accurate description of what this ? company ? is attempting, I'm reasonably sure our members would be interested.
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There is actually a wikipedia page on this concept.
https://en.m.wikipedia.org/wiki/Energy_ … downdraft)
One the problems with this concept is that the pumping power of the water is about half the total power output from the turbine. A small percentage increase in pumping power over baseline, would significantly eat into the power output of the tower. The proposed towers are huge at 400m in diameter and 1000m high. Each would generate as much power as a large nuclear power station. Presumably these towers would be made from steel reinforced concrete, rather like a cooling tower.
The continuous generation of water saturated air would seem to be a positive to me, as these generators are intended for deserts. However, the production of salt aerosols could present a serious environmental problem.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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Calliban,
Agreed. Beyond the existing pumped hydro systems, which can't be dramatically expanded for a reasonable amount of money, long term energy storage is grossly impractical at the scale required. Economic and material resource scarcity reality is starting to reassert itself. Nuclear reactors or liquid hydrocarbon fuels are absolutely necessary to supply base load power. Apart from burning more coal and natural gas, only nuclear reactors are a practical alternative option, which ideologically neutral people have known for quite some time. Waste heat from the reactor fleet can either add to the hot water supply, or reactors can pull double duty by desalinating sea water. Mechanical power, along with hot and cold potable water, are foundational to human society. Electricity is also important in modern times, but only when the output is both clean and stable. The output of so-called "renewable energy" or "green energy" electric generation is not clean (constant 60Hz frequency, perfectly sinusoidal AC power), nor is it stable (multi-hundred GigaWatt power fluctuations for large installations in places like Germany or Australia, which must be internally balanced, else not 1 kilo of coal or cubic meter of natural gas can be shut off at any time).
Electricity is only superficially cheap, and only feasible when it's clean sinusoidal power with near-100% availability, because periods of non-availability are synonymous with a power grid crash, wherein very large / expensive / time consuming to replace pieces of electrical machinery are damaged by brown-outs or black-outs. If the pressure in a compressed air service line varied by +/10%, nobody would even notice. That's a feature of a durable and resilient mechanical system. The very instant available electrical power generation dips 10% below demand, a grid crash is a foregone conclusion.
Apart from computing and certain types of computerized control systems, all electrical and especially all electronic systems are very fragile and failure-prone. An electrical, or now electronic, motorized car door window has dozens of failure modes. So long as your arm still works, your manual mechanical roll-up window still works. It simply cannot fail or cease to work entirely, merely because the car's engine or battery or computer or motor or switch or wiring, ceases to function as intended. If the gear teeth are made from steel and greased during installation, then it will probably never fail until it is physically destroyed. At that point, any electrical or electronic system would be equally destroyed, merely much more expensive and difficult to repair or replace.
Electricity is also incredibly wasteful, because it's an artifact of overall energy-intensive and wasteful industrial processes. All the machinery and industrial processes required to produce electricity (power input, electric generator if the power input is not from photovoltaics, step-up transformers, step-down transformers, power lines, more transformers to convert the electricity to DC power for electronics, more specialty metals and energy-intensive processes to make electronics), is what makes it wasteful. In general, electrical machines are very efficient individually, but not efficient enough to overcome the process and power distribution inefficiencies. If we consider that half of all mining energy input and tailing waste generation is associated with Copper mining alone, it's not cheap or efficient at all. On top of that, we would require Lithium or Sodium and a slew of other specialty metals, in addition to absurdly consumptive semi-conductor production. All are artifacts of other mining processes that co-produce specialty metal ores in conjunction with, for example, Zinc production. If you want rare Earth metals, then you need to mine those more common metals, thus production of the more common metal ores becomes the limiting factor in production of specialty metals. Well, if we mine 10X more Zinc, then it requires 10X more energy input, yet we still need 100X to 1,000X more of the specialty metal that we're actually going after. At some point, too much energy is being devoted to mining instead of all the other uses for energy. Hydrocarbon fuels gave us a temporary "free ride" to devote enormous energy input to what would otherwise be a losing proposition.
Very short term energy storage for powering vehicles is practical when you can get more of the energy out by not suffering the conversion penalties associated with generating electricity, or by not squandering waste heat generated by air compression. The requisite supply of air and hot water doesn't amount to an insurmountable increase in generating or storage capacity, because it doesn't immediately run afoul of specialty metal acquisition from mining. A compressed air / hot water transportation solution is a "flow-through" system, with greater total capacity than a liquid hydrocarbon fuel based system, in which the consumed products are constantly being pushed through the trompes (gravity machines with no moving parts, as you pointed out, and gravity is pretty reliable inside a deep gravity well), service pipeline networks, gas stations, and the commuter vehicle fleet or household appliances. CO2 is the most abundant / non-toxic / readily available refrigerant for refrigerators, air fryer ovens, air conditioners, and onsite electrical generators, which will only need to power LED lights and personal computing devices.
Future homes and cities will require hot and cold water pipes, as well as compressed air pipes. There won't need to be grid-connected electrical systems or natural gas pipelines, drastically reducing the demand for Copper and other energy-intensive specialty metals with strictly limited supplies. Since most consumer electronics are now battery operated, and LED bulbs with small batteries can run for days on a single charge, there won't need to be much in the way of onsite electrical wiring, either. This is an appropriate use for Lithium-ion batteries that won't run into supply constraints. If there is any wiring in new build residential structures, it will consist of small low-voltage DC power cables of the sort used to recharge cell phones. Assuming no external or internal high-voltage / high-amperage electrical wiring, and no natural gas, because short range vehicles use compressed air and hot water, there's very few remaining ignition sources for fires. Home power tools can use compressed air instead of electricity and batteries or gasoline. Someone with hand tools and lubricants can maintain their air powered home workshop and yard tools for the better part of a lifetime.
The first order of business when building a new home will be getting compressed air service lines operating so construction tools can take advantage of onsite compressed air. If there's not enough air, water, and steel to make this new low energy density generating and storage scheme work for light transport and light construction work, then there will certainly never be enough specialty metal to make the electrical equivalent of a Rube Goldberg machine function at the same scale. Over the past 50 years, we've created what was ultimately pointless additional complexity, to attempt to arrive at long term sustainable solutions, only to discover that the additional complexity was a major factor affecting the general practicality of the proposed electrical / electronic solutions at the scale required.
There are 2 to 3 trips I make per year that require a combustion engine, and might otherwise be impractical using compressed air. If the vehicle has a range of 100 miles at 55mph, then perhaps even those trips are practical to do with compressed air. The rest of the time, all of my driving is within 25 miles. Spending 5 minutes to fill up on the other end is not a major problem. I can't easily travel 10 to 25 miles per day without a car, but what powers it is optional. It's rare for my vehicle to achieve 40mph, and almost all driving is under 55mph. The speeds achieved are an artifact of living in a large city with lots of other motorists. Large concentrations of people and vehicles dramatically reduce driving speeds, resulting in lots of start-and-stop driving. I suspect that also describes the overwhelming majority of real world day-to-day driving for your average commuter. I don't think using compressed air vs gasoline would dramatically affect the utility of a car inside a city, and air quality would improve dramatically. The hard requirement there is to make the vehicle and its alternative energy supply cheap, pervasive, easy to use, and easy to maintain. We already maintain compressed natural gas pipelines, so I can't see compressed air being inordinately more difficult, and compressed air is not explosive or particularly harmful to the environment if there is a leak.
We can have 600psi compressed air and hot water service pipelines that draw in air from either the Great Lakes or from the Atlantic and Pacific. We will protect the trompes and pipes with a Silicon-based CVD coating to inhibit corrosion. The pipes will probably live longer than their first cohort of users / beneficiaries. At service stations, the 600psi air can be compressed to 4,410psi / 300 bar. The high pressure parts of the system will likely require recycling roughly every 10 years or so, as pressure cycles take their toll on the steel storage tanks, which are essentially high pressure SCUBA diving tanks presently used at that pressure level to store air for diving activities.
The biggest questions I have are:
1. Will people accept this new way of powering their commuter cars and home appliances, or will they see it as too great an imposition?
2. Can we make the required machinery cheap enough to implement at a global scale?
3. Do we have enough remaining coal and natural gas to do this if we start in the near future?
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Moved to avoid corrupting the CO for Mars topic
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I think ultimately most people will choose whatever option is available to them, that meets their needs at the minimum of cost. Most people could get to where they want to go by bicycle. But this option fails to meet their other needs of safety, speed, comfort, load carrying capacity and protection from weather. A car with a top speed of 60mph, say, and a range of 100km, is less valuable to people than a faster and longer range car. But if it is cheaper to buy and/or run and no less reliable, people may compromise because it offers them a better solution overall. I can see that happening.
Right now, without subsidies, electric cars do not appear to offer people an overriding advantage in any area and they are more expensive to buy and maintain. We have already discussed their poor sustainability from a resource perspective and the extra demand they place on the grid. In important ways, EVs build vulnerability into the transport sector because they require a functioning grid. And the grid is a fragile chain of infrastructure that requires constant balance of supply and demand. As more 'renewables' are added to it, it is becoming less stable. Interest rate rises have restored cost of capital. Unless something dramatic changes to alter their fortunes, the EV craze is likely to be remembered in the same way as the South Sea Bubble, the Dutch Tulip craze and the Darien scheme. Things that all looked like a good idea at the time and wiped out enormous fortunes when they failed.
I cannot say with any confidence that compressed air networks are the way to go for powering transportation. The things this idea has in its favour is the use of abundant low energy cost materials (almost exclusively carbon steels and concrete), relative simplicity (at least compared to electric vehicles), reasonable but not excellent energy efficiency and long system life. But I havn't assessed the capital and operating costs. So the most I can really say is that an air powered transport network is an option worth examining in more detail.
A 500litre compressed air tank, charged to 20MPa (3000psi) will carry 53MJ of energy if the air expands isothermally.
https://tribology-abc.com/abc/thermodynamics.htm
We may be able to approach isothermal conditions if our engine is a multistage expander with reheat in between expansion stages. Essentially, this would look like a gas turbine with heating fins in between stages. Elon Musk's Tesla 3 uses about 0.5MJ of battery energy per km. So assuming that an air car has similar energy requirements, the 500 litre tank should give it a 100km range. So from a technical perspective, this can work.
The weight of the tank is significant, but not excessive. Let us assume a steel with yield strength 600MPa and a design factor of 3. Assume also a spherical pressure tank. For an internal volume of 500 litres, inner radius works out to be 0.5m. Required thickness is 2.5cm (1"). Assuming a steel density 7800kg/m3, weight works out to be 613kg. The air inside the tank would add another 125kg.
If we again use the Tesla 3 as a comparison, its standard curb weight is 1752kg. It's batteries have energy density of 150Wh/kg. So a 50kWh battery would weigh 333kg. About half as much as our air tank, and one-fith the mass of the car. So can air car would weigh 20% more. The Tesla battery carries about 3.5x as much energy, so allows 3.5x more range. But that only matters if people can afford it and care about the range. If your daily commute is 50km, then both the Tesla and the air car will do exactly the same thing and the air car weighs only slightly more.
https://en.m.wikipedia.org/wiki/Tesla_Model_3
Air receiver tanks have a practically unlimited service life provided they are protected from corrosion, impacts and are not pushed over their pressure rating. So it shouldn't be a problem building an air tank that lasts as long as the car, which could be decades. Batteries by contrast are likely to require replacement after 2000 charge cycles. This would limit their life to about 5 years.
On the infrastructure side: Air pipes are bulky compared to power cables for the amount of power carried. But air pipes are steel, not copper, so resources are less of a problem. It can take quite a long time to fill an air tank and can generate high temperatures. On the other hand, an air charging station can actually store air in stationary pressure vessels. This could reduce the required filling time. Energy density could be a problem for transmission of compressed air. At 40 bar(a), air contains 14.76MJ/m3 if expanded isothermally. So a 1m diameter air main, with an internal flowrate of 30m/s, would carry about 350MW of power. If you needed to transmit compressed air long distances across country, the amount of pipework needed would be high. To understand the relative economics we would need to look at the cost of transmission lines and the amount of steel and aluminium needed to make those.
In terms of required air storage volumes: The US transportation system icurs about 3 trillion vehicle miles per year.
https://www.bts.gov/content/us-vehicle-miles
Let us assume that 80% of that traffic is light vehicles. Assuming that filling stations boost air pressure from 40 bar to 200 bar, how much air do we need to store at 40 bar, to meet 1 week of driving demand? Let us assume that these are air vehicles which consume 0.5MJ/km, or 0.8MJ/mile. A week of driving would be 60 billion miles. That would require 30 billion MJ of stored air. That amounts to 2 billion m3 (2km3) of air at 40bar(a). There is ample space in the great lakes and off the continental shelf to store that much air.
Storage would be in thin walled concrete tanks which are ballasted with dredged materials to counteract bouyancy. How much concrete would we need? This is tough to guage. Let us assume that air is stored in underwater concrete cylinders that are 10m wide and 20m tall, with a wall thickness 0.1m. Each container would require 62.8m3 of concrete and would contain 1440m3 of air when full. Each cubic metre of air requires 43.6 litres of concrete. So total concrete needed would be 87.2million m3, or about 200 million tonnes. In 2020, some 14 billion m3 of concrete were produced. So building offshore air storage capacity capable of powering the US vehicle fleet for a week would require about 2.3 days of global concrete production.
https://gccassociation.org/concretefutu … the-world/
There are about 280 million light vehicles in the US, almost one per person.
https://www.statista.com/statistics/183 … ince-1990/
Fitting each vehicle with a steel air tank would require some 172 million tonnes of steel. Assuming an average vehicle lifetime of 20 years, that requires a turnover of 8.6 million tonnes per year. But most of it is recycled. This is a negligible addition to global steel production.
A compressed air based transportation system does not seem to stretch global resources. And it could do most of what an oil powered transportation system would do. We would need more filling stations and a lot of steel pipe to get the air to where we want it. The economics are uncertain, but initial analysis suggests that resources won't be a problem for implimenting this.
Last edited by Calliban (2023-11-18 17:47:38)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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If we needed to store large quantities of compressed air on land, then beyond a certain vessel size it makes sense to use composite steel and concrete pressure vessels.
https://asmedigitalcollection.asme.org/ … essels-for
As pressure vessel volumes increase, wall thickness increases. The point is reached where it is no longer practical to fabricate steel vessels beyond a certain volume and wall thickness. Welding many segments introduces multiple failure points. Weight becomes too excessive to forge the vessel in even a few large pieces. So large vessels are typically made from concrete with steel liners and steel pre-stressing tendons taking the pressure load within a concrete shell. These composite concrete pressure vessels can be built to an almost arbitary size.
Another option for huge vessels is a gravity pressure vessel. This type of vessel would be carved from solid rock, either deep underground or within a mountain. The internal pressure is balanced by the weight of overburden. To store air at a pressure of 40 bar(g) requires some 400 tonnes of overburden per square metre of roof. More overburden may be needed to stabilise vessel walls. A gravity stabilised vessel that is cut into a mountain could be hundreds of metres in diameter. Whilst it would be expensive to build, its working life would be practically unlimited, because the walls would not deform under stress cycles and should not therefore experience fatigue. Parts of the country that are a long way from the coast or great lakes, could build gravity or concrete pressure vessels to store compressed air. The construction of a gravity vessel is essentially a quarrying operation. The quarried material would have value which could help pay for construction.
Last edited by Calliban (2023-11-18 18:43:54)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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Information all good for
The compressed mars air can also be used here Running on Compressed Air?
Also in storage of energy as well.
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SpaceNut,
You posted another fact-free MSN article, which is itself a re-post of an article which also does not include any details. There's no citation of the specific study used in the article (Ashley Nunes and Lucas Woodley have multiple studies published on EVs in Nature and ResearchGate), no inclusion of the methodology used to make that determination, and not one lousy sentence about the scope of the study.
Do you understand why making such claims without evidence doesn't convince people of anything, or at least why that doesn't help the cause of the people who want EVs?
It may sound counterintuitive but you probably don’t drive enough, says grad’s research
Note how the Harvard Gazette actually publishes LINKS TO SOURCES OF STUDIES!:
Woodley’s first big research project, published last year in Nature Sustainability with Nunes as lead author, found EV buying incentives often fail to deliver on the government’s investment. Not only do U.S. subsidies flow to the well-off, with new EVs still averaging nearly $12,000 more per vehicle in 2022 than those powered by fossil fuels, but it turns out tax credits (up to $7,500 in 2023) can incentivize the wrong buyers. Many are led to increase their carbon footprint.
“If you’re somebody who drives a fair amount then you are likely well-suited to drive an electric vehicle,” Woodley said. “If, on the other hand, you’re someone who seldom drives, and the vehicle is mostly going to sit in the garage, then you may counterintuitively be better off owning a gasoline-powered vehicle.”
This is because the batteries that power EVs are responsible for an outsize share of emissions during the manufacturing process. Because EVs are dirtier to build but cleaner to drive, Woodley explained, they must meet certain mileage thresholds before environmental advantages are realized. In the U.S., the typical non-luxury EV needs to log between 28,069 and 68,160 miles before netting any emissions benefits.
...
Woodley used his thesis to investigate the economic impact of the very tax credits for which he and Nunes had advocated. In the end, Woodley concluded that most of the value of used EV tax credits accrued to individuals selling their cars, Stock explained.“Lucas started off in a different place, with the much more conventional view that tax credits would benefit people with lower incomes. After a lot of hard work and analysis, he had quite a different conclusion.”
...
This fall, when he enters Harvard’s Kenneth C. Griffin Graduate School of Arts and Sciences to pursue a Ph.D. in psychology, Woodley will turn his focus to another long-time research interest — intergroup conflict resolution — with Professor Joshua Greene. But first, Woodley has more research to finalize with Nunes, including a paper (still under review) centered on his analysis of EV emissions benefits in all 50 states, given how the country’s patchwork of electricity grids incorporates varying rates of green energy. Among the questions they are asking: In what states do investment in EVs do the least good? And how do the emissions benefits of EVs compare to that of hybrids?The goal is not to discourage EV ownership, Woodley said, but to improve policymaking and maximize emissions reduction per public dollar spent. “Like a lot of people my age, I’m concerned about climate change,” he said. “For me, there’s always the question of how to improve environmental sustainability while recognizing the associated political and financial realities.”
What is a "typical non-luxury EV"?
Teslas aren't being purchased by a bunch of poor people, so we can assume those kinds of EVs require even more driving before there's any emissions benefits.
Last but certainly not least, building an EV and then plugging into a grid that is predominantly powered by hydrocarbon fuels does very little, if anything at all, to reduce emissions. Just like batteries, photovoltaic panels and wind turbines are certainly not "zero emissions" when they're built.
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When young Lucas Woodley belatedly discovers that the US electric grid is almost entirely powered by hydrocarbon fuels, and that electrons produced by "green energy" go to all sources of demand at the instant they're actually producing (963.6 to 2,920 hours of the 8,760 hours in a calendar year), and not just EVs, I think he's going to be shocked and dismayed by how little potential, let alone a demonstrably actualized benefit, there is to driving an EV. EVs are something you build AFTER the entire electric grid isn't burning something to generate electricity, and lasts long enough to actually reduce the emissions associated with re-creating large chunks of the grid every 15 to 25 years.
If the entire US electric grid was powered by reliable nuclear reactors, then it would make a lot more sense to build cars that can plug into that electric grid. We will need to at least double and possibly quadruple the grid's capacity before all 250 to 300 million vehicles on the road can be electrically powered. I guess everyone else will still be driving cars with combustion engines because there won't be enough Lithium or Copper left over for them to use, but at least we can pontificate to them about how clean we all are here in America, as their own CO2 emissions continue to rise. Maybe we can partition off the atmosphere over the US. I can see it now, we'll hang a sign in the sky, that reads as follows: "You are now entering the CO2-free atmosphere of America. Check your CO2 at the door when entering."
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An EV contains some 183lb (83kg) of copper.
https://www.visualcapitalist.com/how-mu … c-vehicle/
To produce 1 billion electric cars we would need 83m tonnes of copper. This doesn't include the copper in chargers or the extra transmission infrastructure. The cars alone require 3.8 years of global copper production.
https://www.zerohedge.com/commodities/a … ualization
An electric car contains 15kg of cobalt and 40kg of nickel. So 1 billion EVs would require 15mt of cobalt (79 years of production) and 40mt of nickel (12 years of production).
https://www.iea.org/data-and-statistics … ional-cars
A compressed air powered car with a 100km range would require a 613kg carbon steel tank. One billion vehicles would therefore need an additional 613 million tonnes of steel. That is 0.24 years of supply. If the average car has a 20 years life, this would increase global steel demand by about 1%. If recycling is used, the additional demand becomes negligible. With 1 billion cars each with a 613kg pressure vessel, some 30.6 million tonnes of pressure vessel steel will require recycling each year. This is enough to justify having a dedicated electric furnace for pressure vessels. This should allow a close to 100% recycling rate.
The economics of CAES improve with increasing scale.
https://www.sciencedirect.com/science/a … 4722007259
At 20MW power, the levelised cost of storage outperforms all battery systems except Na-S. For large grids, we need GW of power.
These results are based upon a system that uses electric power for compression. Better sustainability can be achieved if the compressors are directly driven by the prime movers. This means having wind turbines, solar plants or steam turbines directly coupled to air compressors instead of generators. This eliminates all of materials and complexity associated with production of electricity. Compressors also produce heat as the gas is compressed. This could either be stored to preheat the air prior to expansion or used for another purpose. The temperature of this heat depends upon the amount of compression achieved between intercooling. We could actually design the compression cycle to produce heat that meets the needs of specific industrial users, that could be clustered around the compressor station.
According to the IEA, some 75% of industrial heat needs require a temperature <400°C.
https://www.iea.org/commentaries/clean- … r-industry
As air expands, it cools as internal thermal energy is converted into work. Air can be heated prior to expansion in order to boost work recovery. Or we can make use of the cold produced by the expansion. Ambient heat could be used to heat the air, but this would require multi-stage expansion, with reheat between each stage.
Last edited by Calliban (2023-11-20 13:41:39)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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This explains why heat pumps aren't exactly cornering the heating market.
https://www.zerohedge.com/energy/heatin … ity-us-eia
An August report by the DOE revealed that natural gas is a far cheaper energy source than electricity. The cost of electricity was calculated to be $46.19 per million British thermal units (Btu). Natural gas cost only came to $13.97 per million Btu, which is 3.3 times cheaper than electricity.
The actual COP of a heat pump is highly variable and depends upon the air temperature, ground temperature, the indoor temperature and the delta between the radiator and indoor air temperature. But this link makes it clear that unless COP exceeds 3, there are no cost benefits associated with an electric heat pump. Indeed, the high installation cost requires a COP substantially greater than 3 to break even financially. For air source heat pumps, that is highly unlikely. For ground source, it may be achievable under certain conditions. But the need for a temperature drop across heat exchanging surfaces and other losses not accounted for in simple Carnot based calculation, make the determination of actual COP highly dependant upon specific arrangements.
Last edited by Calliban (2023-11-20 18:02:56)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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Registered passenger vehicle count for select western countries, as of 2021 or 2022:
278,064,000 US
26,200,000 CA
32,200,000 UK
36,700,000 MX
253,000,000 EU
626,164,000 total registered passenger vehicles, as of 2021 or 2022
Proposed air / water powered truck / cross-over SUV weight:
2,445kg (same as the Tesla Model X, a mid-sized crossover SUV)
Yes, modern vehicles are chonkers, for both NHTSA approval and sheer weight of components.
2000kg - steel; primary construction material for frame / chassis, body panels, suspension / brakes
445kg - other materials (Aluminum wheels - 15.06kg/ea for 20" Tesla Model X Slipstream style, interior plastic, rubber seals, seats and belts, dash panel, AC / heating ductwork / air bags / etc)
We could replace plastic with veneer wood to avoid using oil / non-recyclable plastics.
As it was explained to me by our local wheel and tire guy, for heavier vehicles with thin wall tires, which is pretty much all of them now, forged Aluminum does a better job of providing stiffness than steel. Some trucks and SUVs still use steel, but most do not. Aluminum does not corrode as fast as steel, irrespective of type or special coatings, and personal observation confirms his assertion. Ford appears to have learned the hard way that Aluminum frames and body panels don't provide enough strength and stiffness for the chassis frame rails or body panels, so steel is required. Tesla uses giant but very expensive Aluminum forgings as major structural parts of their vehicle chassis, to reduce total parts count and fastener count. For a heavy duty vehicle that someone with hand tools must be able to disassemble, that is a non-starter, regardless of what Sandy Munro thinks. He may be a brilliant engineer, but he's a poor excuse for a repair tech, and thinks the customer is supposed to buy a brand new vehicle if a chassis structural component is damaged. Maybe that was fine for planned obsolescence, but it's not okay now.
2,200kg (steel) * 626,164,000 vehicles = 1,377,560,800,000kg / 1,377,560,800t
75.3kg (Aluminum) * 626,164,000 vehicles = 47,150,149,200kg / 47,150,149t
137,756,080t of steel and 4,715t of Aluminum per year, over 10 years. We're not making half a billion vehicles in less than 10 years, not even ones mostly made from steel, even when they're stupidly simple.
Source for Tesla Model X Aluminum Wheel Weights:
Unplugged Performance - Tesla Wheel and Tire Gudie
Tesla Model X 100kWh long range battery weighs 771kg.
197kg estimated weight for a 275L internal capacity Type IV H2 tank, holding air
224kg estimated weight of air compressed to 70MPa
421kg of combined storage tank and compressed air weight
126,108,300J of energy, 1,224,000J of energy consumed per mile
99C - 20C = 79C
79C * 4,186J/kgC = 330,694J/kg of water heated to 99C
126,108,300J / 330,694J/kg = 381.35kg / 100.62 gallons of water heated to 99C
802.35kg for the hot water, air storage tanks, and air
Vehicle range is just over 100 miles. Yes, that still looks pretty good to me. Air and water are very low energy density. The fact that we can get that kind of range from the vehicle is pretty good.
The other option is hot water and a CO2-based refrigeration loop to draw the heat out of the water using an atmospheric heat exchanger, but then you only get half as much energy, at best, because now you're running a heat engine, as opposed to using the energy from isothermal gas expansion.
What if we only used hot water at 99C and only converted 35% of the thermal energy in the hot water to mechanical work output?
330,694J/kg * 802.35kg = 265,332,330.9J of energy
265,332,330.9J * 0.35 (35% efficiency) = 92,866,315.815J of energy
What if we went to a 200C system pressurized to 225.52psi?
(200C-20C) * 4,186J/kg = 753,480J/kg
753,480J/kg * 0.35 = 263,718J/kg
122,400,000J (100 miles of range) / 263,718J/kg = 464kg / 122.5 gallons of water at 200C
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Kbd512, what you have presented looks like a practical solution. It is at least possible from a materials viewpoint and a 100-mile range is something most people could live with. The hot water that is needed can be provided by sustainable sources. The compression process itself, concentrated solar heat, a mechanical windmill with a friction brake, geothermal heat, biomass, an SMR, reistance heaters powered by curtailed wind electricity, etc. There are a lot of options. Aluminium-magnesium alloys have been used in ship frames. This is every bit as harsh an environment as a road vehicle chassis has to face. Wave action continuously flexes the hull, but they seem to do OK.
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Peter Zeihan explains that the global lithium resource is in no way adequate to meet the needs of an EV transition. There is enough in Australia to allow an attempt to be made in the US, but it isn't a winning bet for anyone.
https://m.youtube.com/watch?v=af3_0CrnH7o
This is frankly old news for us now, but it is important to keep stressing the point because the world at large still hasn't cottoned on. Lithium is only one of the material resources whose global production must literally explode to make an EV future possible. Zeihan doesn't mention these in this short clip, but is well aware of them.
Greentech enthusiasts still havn't realised how a high interest rate environment changes the investment climate compared to what they got used to between 2009 and 2021. That 12 year period really was unprecedented in history. It happened to coincide with the Chinese infrastructure driven expansion model and the shale revolution. Interest rates are now back to historical averages, the Chinese economy is shrinking as percentage of global GDP (a trend that is accelerating), Russia is dropping out as a global commodity supplier and US shale production is no longer growing at the rates neccesary keep a lid on energy inflation. This means that all of the factors that played in favour of greentech since 2009 have gone into reverse.
Capital intensive renewables could still have a place in this environment, if the infrastructure is impressively long lived. If that is the case, then whatever capital flows into this sector is cumulative and the infrastructure can build slowly over time. That isn't really doable with PV systems or wind energy as it is presently configured. But there are systems that can be built once and will last for decades or centuries with a competant maintenance regime. We have discussed some of these before. Solar thermal based systems, geothermal heat mining, wind power using recyclable and low energy materials. If we can figure these things out, then hopefully lots of other people are simultaneously reaching the same conclusions.
Last edited by Calliban (2023-11-21 03:26:52)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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Most towns will not be able to afford district heating.
Why do you think this? We could afford to build out the infrasatructure for town gas and water to homes when we were far poorer than we are now. I don't see why we couldn't afford to provide district (or neighborhood?) heating, especially if we can salvage materials and potentially already built infrastructure to do it (catabolic collapse!).
But a town can be provided with a heated sitting room, that also functions as a library, with a cafe. This would be attached to an interseasonal heat store.
Now this is something we could plausibly start building out right now. Churches, schools, civic buildings could be persuaded to go intraseasonal geo heat pumps, and with that in place we have fallback centres for surviving shocks. And serve as the anchors for building neighbourhood heating around them, if overbuilt...
Use what is abundant and build to last
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Most towns will not be able to afford district heating.
Why do you think this? We could afford to build out the infrasatructure for town gas and water to homes when we were far poorer than we are now. I don't see why we couldn't afford to provide district (or neighborhood?) heating, especially if we can salvage materials and potentially already built infrastructure to do it (catabolic collapse!).
But a town can be provided with a heated sitting room, that also functions as a library, with a cafe. This would be attached to an interseasonal heat store.
Now this is something we could plausibly start building out right now. Churches, schools, civic buildings could be persuaded to go intraseasonal geo heat pumps, and with that in place we have fallback centres for surviving shocks. And serve as the anchors for building neighbourhood heating around them, if overbuilt...
Consider how dysfunctional Britain has become. The British government is a joke and is unable or unwilling to defend its borders as barbarians arrive on our beaches. Consider their recent record on infrastructure projects. It has so far cost £25bn and 11 years to build a 3.2GW nuclear power station. The London cross rail project cost £130bn and never finished. These projects are small compared to building heat distribution systems covering every street of every town an city. Maybe I am being cynical, but I have no confidence at all in the abilities of the UK government and industry to pull off a project of this scale. I would be happy to be wrong.
Building an interseasonal heat store with some buildings clustered around it is a far more modest project. It can be done without state level resources. Which is why I propose it here. This is a fall back plan of sorts. How to keep life tolerable if the government is as useless as I think it is.
Last edited by Calliban (2023-11-22 14:04:27)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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