Wireless/induction EV charging revolution

Calliban · 2021-11-17 14:02:40

The longer the allowed recharging time, the less the burden on the grid. The optimum strategy would be to allow vehicle range to decline in proportion to the more limited energy density of the batteries and swap the battery and allow the spent battery to recharge over a longer period of time, say 24 hours. A 30-mile range Li-ion battery would weigh a lot less than a tenth as much as a 300-mile battery, because a lot of the charge needed in the 300-mile battery is used to carry its own weight. That is why a 400-mile range electric battery weighs as much as a small car. A 1000-mile battery may even be infinitely heavy, because in the end, almost all energy would be consumed overcoming the frictional forces imposed by its own enormous mass. If you attempt to build a long range vehicle using a low energy density battery, the mass of the battery required DOES NOT scale linearly with increasing range. You ultimately end up with a singularity. In practical terms, a 300 mile battery weighs a lot more than 10x as much as a 30 mile battery. This is why it makes no sense trying to engineer long range battery electric vehicles. The thing ends up running up its own arse. To be affordable, range must decline in proportion to energy density. So a 30-mile range battery would probably weigh something like 15kg, as the car would weigh a lot less with a smaller battery.

A 15kg mass battery is small enough to remove and replace by hand. If the car has a range of 30 miles, say, then the number of additional batteries needed in a nation, is roughly equal to the number of journeys greater than 30 miles each day, multiplied by the average journey length, divided by 30.

It would make travel a bit more cumbersome, but it would appear to be the only way of allowing low energy density batteries to meet a long range requirement affordably, without placing absurd power demands on the grid. It is a more elegant solution than fitting every car with a 400 mile battery, because the number of batteries the car uses is always proportional to journey length and most car journeys are short. As most journeys are shorter than 30 miles, the average person could be served by a 30-mile range electric car, provided that there remained the option of swapping batteries for longer journeys.

The other option is for the average person to have a 30-mile range electric car for every day use. At the end of each journey, they can remove the battery and recharge it by plugging it into an ordinary socket in their house or place of work. An 8-hour recharging time would be quite acceptable, if the charging is overnight or during a workday. If they need to drive further, then they hire a petrol or diesel fuelled car for that purpose.

A compressed air vehicle might be a better form of stored energy vehicle. We can build 30-mile range compressed air vehicles with ordinary steel pressure tanks. And we can store compressed air in pre-stressed concrete tanks at filling stations. Compressed air can be transfered to the tanks far more rapidly than a battery can be charged. And the tanks will not wear out in the lifetime of the vehicle.

One final point to think about. EVs have been the work horses of mass transit in many nations for over a century. They are affordable, fast and their burden on the grid is small. They just don't run on batteries. They draw power directly from grid. It wouldn't be easy to power a car in that way. But it already works for trains, trams and some buses. If we are headed into an electric vehicle future, this is what it is likely to look like.

Last edited by Calliban (2021-11-17 14:44:23)

louis · 2021-11-17 15:41:48

Calliban wrote:

The longer the allowed recharging time, the less the burden on the grid.

I don't see how that could be. Or are you arguing that there will be peak charging times. Surely the answer is to use differential pricing. If, say, nighttime electricity was offered at 50% of daytime cost, I think most people would charge their cars overnight on home induction pads. In the UK, we do have a problem in that maybe something like 25% of motorists don't have off-street parking.

The optimum strategy would be to allow vehicle range to decline in proportion to the more limited energy density of the batteries and swap the battery and allow the spent battery to recharge over a longer period of time, say 24 hours. A 30-mile range Li-ion battery would weigh a lot less than a tenth as much as a 300-mile battery, because a lot of the charge needed in the 300-mile battery is used to carry its own weight. That is why a 400-mile range electric battery weighs as much as a small car. A 1000-mile battery may even be infinitely heavy, because in the end, almost all energy would be consumed overcoming the frictional forces imposed by its own enormous mass. If you attempt to build a long range vehicle using a low energy density battery, the mass of the battery required DOES NOT scale linearly with increasing range. You ultimately end up with a singularity. In practical terms, a 300 mile battery weighs a lot more than 10x as much as a 30 mile battery. This is why it makes no sense trying to engineer long range battery electric vehicles. The thing ends up running up its own arse. To be affordable, range must decline in proportion to energy density. So a 30-mile range battery would probably weigh something like 15kg, as the car would weigh a lot less with a smaller battery.

I would recommend the video on the other thread I started (The EV Battery Revolution) which suggests the 300 mile range battery may not be as out of reach as you suggest. But I take your point and it seems to me it's a lot cheaper to install induction coils (assuming the work as planned) and feed electricity to smaller battery packs in EVs rather than building lots and lots of batteries which, as you observe, then have to carry their own weight. Whether a 30 mile range battery will be acceptable in terms of "range anxiety". Probably 90% of the population live within 10 miles of an A road. Things might eventually settle down so people who live in remote areas (plenty of those in places like the USA, Canada, and Australia for instance go for 300 mile range, people living in rural areas might opt for 100 mile range and people living in urban settings might be happy to settle for 30 miles.

A 15kg mass battery is small enough to remove and replace by hand. If the car has a range of 30 miles, say, then the number of additional batteries needed in a nation, is roughly equal to the number of journeys greater than 30 miles each day, multiplied by the average journey length, divided by 30.

It would make travel a bit more cumbersome, but it would appear to be the only way of allowing low energy density batteries to meet a long range requirement affordably, without placing absurd power demands on the grid. It is a more elegant solution than fitting every car with a 400 mile battery, because the number of batteries the car uses is always proportional to journey length and most car journeys are short. As most journeys are shorter than 30 miles, the average person could be served by a 30-mile range electric car, provided that there remained the option of swapping batteries for longer journeys.

I'm not a fan of battery swapping these days. It was something that was supposed to be happening in Israel but never did.

The other option is for the average person to have a 30-mile range electric car for every day use. At the end of each journey, they can remove the battery and recharge it by plugging it into an ordinary socket in their house or place of work. An 8-hour recharging time would be quite acceptable, if the charging is overnight or during a workday. If they need to drive further, then they hire a petrol or diesel fuelled car for that purpose.

I'm beginning to think you're taking the mickey! lol Remover the battery!! No way, Jose. Electric roads will provide charging that is an improvement on the 4 minute wait filling up you petrol tank. Likewise with stationary induction pads at home.

A compressed air vehicle might be a better form of stored energy vehicle. We can build 30-mile range compressed air vehicles with ordinary steel pressure tanks. And we can store compressed air in pre-stressed concrete tanks at filling stations. Compressed air can be transfered to the tanks far more rapidly than a battery can be charged. And the tanks will not wear out in the lifetime of the vehicle.
One final point to think about. EVs have been the work horses of mass transit in many nations for over a century. They are affordable, fast and their burden on the grid is small. They just don't run on batteries. They draw power directly from grid. It wouldn't be easy to power a car in that way. But it already works for trains, trams and some buses. If we are headed into an electric vehicle future, this is what it is likely to look like.

The video on the other thread indicates Tesla are getting towards the million mile battery - a battery that comfortably exceeds the lifetime of the vehicle. There was a guy in the UK developing a compressed air vehicle. No doubt the technology is feasible but I think there are a lot of issues.

I do recommend the video on the other thread. It explains how really the Tesla Revolution is very profound. I can't see petrol vehicles surviving for more than 10 years at this rate. Why would you buy a vehicle that is more costly than an EV, costs more to run and has higher maintenance bills, plus a shorter life?

Calliban · 2021-11-17 16:02:06

louis wrote:

Calliban wrote:
The longer the allowed recharging time, the less the burden on the grid.
I don't see how that could be. Or are you arguing that there will be peak charging times. Surely the answer is to use differential pricing. If, say, nighttime electricity was offered at 50% of daytime cost, I think most people would charge their cars overnight on home induction pads. In the UK, we do have a problem in that maybe something like 25% of motorists don't have off-street parking.

So let me get this straight. You have a 200 mile journey ahead of you. You leave the motorway ready to use that wireless recharging technology only to find that differential pricing has increased the cost of power to £1/kWh. Are you really going to wait until 2am, so that you can use the wireless charger to recharge your car in 6 minutes? At what point do you get real about this?

Electric roads? You really think that governments are going to be able to afford to embed induction coils in hundreds of thousands of miles of roads, all around the world? Wake up to reality. Government deficits are exploding. Unfunded future liabilities of all kinds are growing far more rapidly than tax revenues. Government debt is following an exponential curve. You remember the final salary pension? How many people in their 40s have one of those now? What proportion of people in their 20s can afford to run a car compared to twenty years ago? While you fantasise about things like this, the world is collapsing around you.

Last edited by Calliban (2021-11-17 16:14:25)

kbd512 · 2021-11-17 16:12:27

Calliban,

Zero Pollution Motors Air Pod

To your point, the AirPod is a 4 seat and 4 wheel urban vehicle, better known as "a real car". It uses a 7kW / 10hp air motor and achieves a range of 130km/80mi to 150km/93mi. It can travel at speeds of up to 50mph. It has a curb weight of 280kg / 617lbs. The most luxurious model sells for $10,880 USD. You could either use the expanding / cold air as air conditioning and mount a solar panel to the roof to provide fan power. Their vehicle uses a CFRP chassis (CF fabric over a PE foam, sandwich core construction) and CFRP air tanks, which is why it costs so much. If mass manufacturing can cut the cost of batteries, then it can certainly cut the cost of CFRP compressed air tanks.

It takes 3 minutes to fill the tank using a service station air compressor and uses $2USD worth of electricity. The CFRP tanks are rated for 20,000 refill cycles (1.6 million to 2 million miles of driving). The air tank has sufficient capacity for a 100mile range when driven at 25mph or less speeds, so your cost per mile is $0.02USD to $0.025USD (2 to 2.5 pennies). No electric or gasoline powered car will ever beat that cost of ownership. Atmospheric air is also the only kind of alternative fuel that doesn't require extreme technology, that can refill in mere minutes without bringing down the entire electric power grid. Going faster is a matter of adding more tanks and an additional air motor.

The air motor does require 0.85 quarts / 0.8L of lubricant oil and requires 50,000km oil changes. The onboard air compressor can recharge the car in 3 to 4 hours using a standard 120V AC wall outlet. Since there's far less danger of burning your house down, you can probably leave the vehicle in your garage unattended while it's "charging".

Calliban · 2021-11-17 16:53:29

Compressed air has efficiency problems if it is stored at high pressure and expanded adiabatically. So either we accept lower pressure, short range and reduce vehicle weight and top speed, or we employ compressed air as part of a hybrid concept. The above concept appears to achieve good efficiency by keeping weight and air resistance losses as low as possible and recovering braking energy. It is a neat solution.

If employed as part of a hybrid, efficiency is much better, because the waste heat from the engine can be used to heat the air during expansion. Capital cost will be greater. Recovering braking energy in compressed air is substantially more efficient than recovering it as electrical energy. A vehicle running on relatively low pressure compressed air in alloy steel tanks, would be relatively cheap to build and would not wear out in the way batteries do, but would have very limited range. Adding a small single-cylinder diesel engine and making it a hybrid, would boost range, whilst retaining a lot of the efficiency benefits. I suspect that this would be the preferred option.

I begin to wonder what we are trying to achieve with all of this. Is the goal to allow life as usual with lower CO2 emissions? The problem with this is that the deteriorating energy dynamic is making life as usual unaffordable to an increasing proportion of the population. Most of the electric vehicle schemes make this problem worse rather than better. I suspect that the best solution is highly fuel efficient diesel or petrol fuelled vehicles, with hybrid options chosen to reduce fuel consumption, without raising capital costs beyond what people can afford. Compressed air or hydraulic accumulators could do this by allowing braking energy recovery and launch assist. Electric cars could be more affordable if people were to accept the range limitations. But a lot of expectations around rapid charging, 500 mile range or electric roads, are out of touch with the reality of what is going to be affordable in the years ahead.

What we really need is transportation options that will be cheaper, rather than more expensive. Most people will sacrifice a lot of added gadgetry and power hogging stuff like seat heaters and air conditioning, if it makes the difference between being able to afford a car or not. I don't see how this wireless, fast charging infrastructure helps us achieve that goal at all. If we had very cheap electricity and expanding prosperity, then this sort of thing might be an affordable overhead. But electricity has grown continuously more expensive. All kinds of costs are rising faster than the average man's pay. Governments are flirting with bankruptcy. The problem that needs to be solved is not how we design an expensive electrical system that matches the performance of petroleum vehicles, but how we produce a transportation solution that will be affordable to people whose incomes are shrinking?

As I have noted before, our problem is not running out of fossil fuels, but that deteriorating EROI is making those fuels more expensive to produce. Because of the underlying energy intensity of transportation, this cannot be reflected in higher prices for very long, without causing recession. What is the best thing to do in that situation? We need solutions that hold down costs for consumers, whilst allowing producers to remain profitable. Improvements in fuel economy would do that. But it must be done in ways that avoid inflating the capital cost of vehicles. What people can afford is declining. A petrol / diesel compressed air hybrid, may turn out to be an optimal solution. Assuming idiot governments don't start banning anything with an engine in it.

Last edited by Calliban (2021-11-17 17:22:53)

louis · 2021-11-17 17:36:35

Calliban wrote:

louis wrote:
Calliban wrote:
The longer the allowed recharging time, the less the burden on the grid.
I don't see how that could be. Or are you arguing that there will be peak charging times. Surely the answer is to use differential pricing. If, say, nighttime electricity was offered at 50% of daytime cost, I think most people would charge their cars overnight on home induction pads. In the UK, we do have a problem in that maybe something like 25% of motorists don't have off-street parking.
So let me get this straight. You have a 200 mile journey ahead of you. You leave the motorway ready to use that wireless recharging technology only to find that differential pricing has increased the cost of power to £1/kWh. Are you really going to wait until 2am, so that you can use the wireless charger to recharge your car in 6 minutes? At what point do you get real about this?
Electric roads? You really think that governments are going to be able to afford to embed induction coils in hundreds of thousands of miles of roads, all around the world? Wake up to reality. Government deficits are exploding. Unfunded future liabilities of all kinds are growing far more rapidly than tax revenues. Government debt is following an exponential curve. You remember the final salary pension? How many people in their 40s have one of those now? What proportion of people in their 20s can afford to run a car compared to twenty years ago? While you fantasise about things like this, the world is collapsing around you.

Yes, it will make a difference. People will make sure their cars are charged up before starting on a Motorway. In fact for the vast majority of people this won't be an issue as they simply park over their home induction pad. I think with digital technology, you can in all likelihood make this very subtle in terms of pricing. So every user could have an initial allowance - let's say 1000 miles at the lower rate. So this might cover 3 or 4 major trips to see relatives in a year. But after that you would be paying the higher rate to use electric roads. So that might catch some regular commuters who will certainly maximise the cheap rate nighttime charge but may still use daytime charging on the motorway. You would probably find that with fleet cars where people are doing high mileage every day they might opt to use big battery cars rather than rely on electric roads because they can charge overnight.

IIRC the cost of inserting induction coils as part of a motorway maintenance programme was something like £1 millon a mile. So 100s of thousands of miles would mean 100s of billions of pounds but that would be over decades and across the whole planet - affordable. We have 2300 miles of motorway in the UK. If my remembered figure is correct, then if say we had 1 in every 4 miles of motorway fitted with induction coils that would be 575 x £ 1 million every 5 years perhaps - only about £100 million per annum. Even if every single mile was covered that would still only be £400 million per annum. And of course you can recoup that cost through charging (as in money!).

louis · 2021-11-17 17:47:11

There's something telling me Musk would have gone down this route if it was the best path. Is there any mention of noise? How noisy is a compressed air vehicle? I'm think how noisy anything like a leaf blower or a vaccuum cleaner is where air is blowing through.

EVs are already outperfoming petrol vehicles in many respects e.g. acceleration, pollution and fuel cost. The point is that we are still right at the beginning of the modern EV iteration...Musk's plans are realistic and if he can achieve his aims then ICEs are going to be a thing of the past.

kbd512 wrote:

Calliban,
Zero Pollution Motors Air Pod
To your point, the AirPod is a 4 seat and 4 wheel urban vehicle, better known as "a real car". It uses a 7kW / 10hp air motor and achieves a range of 130km/80mi to 150km/93mi. It can travel at speeds of up to 50mph. It has a curb weight of 280kg / 617lbs. The most luxurious model sells for $10,880 USD. You could either use the expanding / cold air as air conditioning and mount a solar panel to the roof to provide fan power. Their vehicle uses a CFRP chassis (CF fabric over a PE foam, sandwich core construction) and CFRP air tanks, which is why it costs so much. If mass manufacturing can cut the cost of batteries, then it can certainly cut the cost of CFRP compressed air tanks.
It takes 3 minutes to fill the tank using a service station air compressor and uses $2USD worth of electricity. The CFRP tanks are rated for 20,000 refill cycles (1.6 million to 2 million miles of driving). The air tank has sufficient capacity for a 100mile range when driven at 25mph or less speeds, so your cost per mile is $0.02USD to $0.025USD (2 to 2.5 pennies). No electric or gasoline powered car will ever beat that cost of ownership. Atmospheric air is also the only kind of alternative fuel that doesn't require extreme technology, that can refill in mere minutes without bringing down the entire electric power grid. Going faster is a matter of adding more tanks and an additional air motor.
The air motor does require 0.85 quarts / 0.8L of lubricant oil and requires 50,000km oil changes. The onboard air compressor can recharge the car in 3 to 4 hours using a standard 120V AC wall outlet. Since there's far less danger of burning your house down, you can probably leave the vehicle in your garage unattended while it's "charging".

Calliban · 2021-11-17 18:48:38

Regarding the whole 'electric cars are cheaper' thing:

A modern diesel will get 60mpg in average driving conditions, which equates to around 25.5km/litre. One litre of diesel contains 32-40MJ of energy, say 36MJ on average. So that's an energy expenditure of 1.4MJ/km. The Tesla 3 will get 350km range on a 50kWh battery, so that's 0.51MJ/km.

On the face of it, the electric vehicle has much lower energy consumption. But...Electricity must be generated. Often this involves burning fuel. It may be coal in boiler or more likely, methane in a gas turbine. Roughly two units of fuel must be burned to produce one unit of electricity. Then there are losses of 10% in transmission. So that's 2.2 units of fuel per unit delivered to the vehicle. Then there are charging losses in the battery: another 10%. So the Tesla actually consumes 1.27MJ energy per km. But remember the significant embodied energy of the battery, which has an effective life of around 6 years? Adding this in and the Tesla will have about the same lifetime energy consumption as a modern diesel.

How the heck can this be? The energy consumption of a vehicle is driven by a combination of air resistance and rolling resistance. Two similarly sized and shaped vehicles of the same mass, will require about the same driving energy consumption all else being equal. The Tesla 3 has lower air resistance than most other vehicles of its size range due to lower drag coefficient. This has nothing to do with electric propulsion, it depends upon aerodynamic shape.

How do they compare on running cost? One litre of diesel (36MJ) sells for about £1.30 in the UK, so thats 3.6pence per MJ. At 60mpg, our car will have fuel cost of 5 pence per km. Electricity retails at £0.3/kWh, so the Tesla 3 comes in at 4.72 pence per km, inclusive of a 10% loss in charging. That is marginally cheaper. But what about tax? About two-thirds of the cost of diesel is attributable to tax. Electricity is hardly taxed at all. Overall taxation levels for electricity are about 1/10th those on road vehicle fuels on a MJ basis.

So before tax, the Tesla 3 has energy costs nearly three time higher than an equivalent diesel powered vehicle. Battery electric vehicles are no more energy efficient than diesel vehicles and before tax, they are no cheaper to run. In fact, they are considerably more expensive - almost 3x more per km travelled. Tax of course, makes all the difference. The question is, how much longer the UK exchequer can continue to exclude road used electricity from taxation? If they were to levy the same level of tax on road used electricity as they presently receive from fuel, then the cost of electric vehicle travel per km, would roughly double. Presumably, this will need to happen, eventually.

Why would electric vehicles be so much more expensive to operate, prior to taxation effects? Electricity production requires a long line of infrastructure, with heavy embedded energy costs at each point. A gas turbine is marginally more efficient than a diesel engine. But that energy must be transmitted and sold with profit margins. Electricity suppliers are obliged to purchase renewable energy, in addition to maintaining fossil fuel and nuclear powerplants. So they are paying for two sets of capital and operating costs instead of one.

Electric vehicles appear to be almost cost competitive with diesel powered vehicles, provided that purchase is subsidised by government. But all cost advantages disappear if both sources of energy are taxed at the same rate and electric will be substantially more expensive. The cost of electric power could of course be reduced substantially by ceasing renewable obligations and building a fleet of dependable baseliad coal or nuclear powerplants. But governments don't want to do this either. One wonders what future historians will make of the folly that we are forced to endure in the name of green political idealism.

Last edited by Calliban (2021-11-17 19:05:02)

SpaceNut · 2021-11-17 19:02:43

Luois, for you post 27; I gave you battery range in post 22 and in post 23 you called it not relative to technology but that is what the technology is attempting to have inroads into. You can not charge a vehicle unattended as that's going to be a problem such as your home burning down....no amount of safety shut downs will work if the battery ignites and they do. Having a charge RF system does not change this...

Kbd512's post on the air car can actually extend its range with a solar roof powered air compressor to fill it a portion of its use and while its setting still parked for the day to top it off for the next use.

Calliban · 2021-11-17 19:58:41

kbd512 wrote:

Calliban,
Zero Pollution Motors Air Pod
To your point, the AirPod is a 4 seat and 4 wheel urban vehicle, better known as "a real car". It uses a 7kW / 10hp air motor and achieves a range of 130km/80mi to 150km/93mi. It can travel at speeds of up to 50mph. It has a curb weight of 280kg / 617lbs. The most luxurious model sells for $10,880 USD. You could either use the expanding / cold air as air conditioning and mount a solar panel to the roof to provide fan power. Their vehicle uses a CFRP chassis (CF fabric over a PE foam, sandwich core construction) and CFRP air tanks, which is why it costs so much. If mass manufacturing can cut the cost of batteries, then it can certainly cut the cost of CFRP compressed air tanks.
It takes 3 minutes to fill the tank using a service station air compressor and uses $2USD worth of electricity. The CFRP tanks are rated for 20,000 refill cycles (1.6 million to 2 million miles of driving). The air tank has sufficient capacity for a 100mile range when driven at 25mph or less speeds, so your cost per mile is $0.02USD to $0.025USD (2 to 2.5 pennies). No electric or gasoline powered car will ever beat that cost of ownership. Atmospheric air is also the only kind of alternative fuel that doesn't require extreme technology, that can refill in mere minutes without bringing down the entire electric power grid. Going faster is a matter of adding more tanks and an additional air motor.
The air motor does require 0.85 quarts / 0.8L of lubricant oil and requires 50,000km oil changes. The onboard air compressor can recharge the car in 3 to 4 hours using a standard 120V AC wall outlet. Since there's far less danger of burning your house down, you can probably leave the vehicle in your garage unattended while it's "charging".

Reading this again, it is certainly impressive. One thing that makes it altogether more sustainable is the fact that we can store compressed air in pressure vessels before filling the vehicles. This allows a more constant load on the grid. Steel pressure vessels do not wear out. Within design factors, they have effectively infinite stress cycles. The same is true for concrete pressure vessels pre-stressed with steel tendons. They will still be good a century from now. There is even the possibility of storing compressed air n flexible bags under the sea or in underground chambers. The CFRP isn't quite so forgiving. But 20,000 refill cycles is still over 50 years if you refill once per day. This looks like a sustainable option from an embodied energy viewpoint. The tanks probably aren't easily recyclable. But they would last 10x longer than batteries.

One thing that would improve overall energy efficiency is to locate compression stations close to large heat loads and use waste heat for heating purposes. Alternatively, hot water on the vehicle could raise the efficiency of the air engine and could carry around 0.5MJ/kg through a combination of latent and sensible heat. All considered, the efficiency of CAES could reach 70% if heat could be employed in this way. It may turn out to be more efficient to recover breaking energy as heat, which then increases the expansion energy of the air during acceleration. Interesting stuff.

I don't honestly know why Musk did not opt for this instead of Li-ion. In the words of Gandalf: "Even the wisest cannot see all ends". Musk took his best shot with the knowledge he had.

Last edited by Calliban (2021-11-17 20:04:23)

SpaceNut · 2021-11-17 20:02:07

Here is the topic we have on Running on Compressed Air?

I believe air car is in there...

kbd512 · 2021-11-17 20:25:45

Louis,

louis wrote:

There's something telling me Musk would have gone down this route if it was the best path. Is there any mention of noise? How noisy is a compressed air vehicle? I'm think how noisy anything like a leaf blower or a vaccuum cleaner is where air is blowing through.

Vacuum cleaners and leaf blowers are noisy because they're accelerating air to high velocities using a turbine wheel connected to an electric motor or combustion engine. An engine extracting power from compressed air is the opposite of a leaf blower. If expanded air has very little energy left in it as it exits the engine, then it won't make much noise, because air velocity directly affects noise levels.

Air tools, the better analogy I think you were after, are moderately noisy because they're very inefficient. Air tool manufacturers are far more concerned about power density per unit weight than extracting as much power from the compressed air as they can. The air coming out of an air powered drill, for example, is still moving at significant velocity.

louis wrote:

EVs are already outperfoming petrol vehicles in many respects e.g. acceleration, pollution and fuel cost. The point is that we are still right at the beginning of the modern EV iteration...Musk's plans are realistic and if he can achieve his aims then ICEs are going to be a thing of the past.

Acceleration is a function of power-to-weight ratio. All combustion engine powered vehicles designed for performance easily beat battery powered vehicles. The major manufacturers don't build street cars to produce better track times than other street cars, because street driving is not a race, even if some dimwits insist on racing in the street.

To that point, there is no such thing as an EV that outperforms a combustion engine powered vehicle, except on emissions, and even that is very misleading and often provably false. Emissions don't begin and end with the operating of the vehicle itself.

Exhibit A:

The 2021 Tesla Model 3 weighs 4,250 pounds and has 430hp. A few software tweaks boosted that to 543hp. Well, zippity-doo-dah. That's still lame as hell compared to LS engines plucked out of the junk yards.

The 2008 Pontiac GTO weighs 3,750 pounds and has a 400hp LS V8 engine. As performance vehicles go, the last generation of "The Goat" is none to remarkable, as it was made for luxury as much as performance. An eBay turbo from China can easily boost that to 800hp. With a little bit bigger turbo, I can make up to 1,000hp on stock internal parts in the LS engine. The transmission will have to be upgraded, but this is a 10+ year old car that I paid peanuts for and I'm re-building it to show another ignorant EV owner how basic physics works. With a "built" LS that I pay around $20K for, I can reliably make 1,500hp on pump gas. By "reliably", I don't mean for a few seconds, but for hours on end. The number of shade tree mechanics who have turned stock LS engines into 600hp to 1,000hp tire shredders is absolutely incredible.

I can keep adding boost to keep making more power, without adding more than 100 pounds of weight to my vehicle, because my choice of "fuel" has 31X greater energy density per unit weight, when compared to the 400Watt-hour/kg Tesla 4680 Lithium-ion batteries that still don't exist in any Tesla vehicles on the road. The 100 pounds I added can be taken out by removing the boat anchor seats and replacing them with race buckets and 5-point harnesses, as mandated by a NHRA tech inspection for any car faster than 11 seconds.

I don't care if you paid a million dollars for a Tesla Model BS Edition, I'll beat your your 60 foot time, your 0-60 time, you 1/8 mile time, and your 1/4 mile time, every single time. If you try to drag race with me using a car that weighs substantially more and makes substantially less horsepower, then you're doomed to lose every single time, because that's how physics works.

People were turning in the same track times of the latest Teslas using Pro Stock cars, before I was born. This was years before EFI was present in the street cars of the time.

Since you like YouTube so much, please learn something about racing:

THE FIRST 15 YEARS OF NHRA PRO STOCK: A QUICK LOOK

These are literal stock cars purchased off of dealership showroom floors in 2021 (turning in better 1/4 mile times than battery electronic junk that cost more than 10 times as much):

NHRA U.S. NATIONALS 2021 - THE REAL FACTORY HOT RODS, FACTORY STOCK SHOWDOWN

Take note that a $80,000 Hemi powered Dodge Challenger and a LS powered Chevy Camaro both turned in a better quarter mile time than a $2.4M Rimac Nevera battery electric snail. These are stock steel cars. The hood is Carbon Fiber because they come that way from the factory. They're also using stock size tires.

To add insult to injury, we have 6,000 pound Cummins 12-valve trucks turning in track times less than 1 second different than a Tesla Model S Plaid:

TRIPLE Turbo Cummins - 9 Second TRUCK!?

The Cummins has the additional benefit of sounding a lot like a fighter jet taking off, rather than obnoxious whiny electric motors.

ICEs will never be a thing of the past, so long as there are refrigerators. Since every single Tesla is an over-priced refrigerator, an appliance on wheels, they'll keep whomping the snot out of BEVs until the ignorance has been overcome.

kbd512 · 2021-11-17 21:15:35

It's almost as if boilerplate physics isn't even tangentially affected by anyone's ideology or personal preferences for motor vehicles, and that all the forces in the universe are simply doing what they've always done and always will do, totally oblivious to any human ideas that a handful of people use to try (and mostly fail, thankfully) to convince everyone else that physics isn't real.

Enter a Tesla Model S Plaid into NHRA's Factory Stock showdown and watch it lose every single time to any given Dodge Challenger or Chevy Camaro or Ford Mustang in the race that doesn't suffer a driver-induced failure.

Enter that same Tesla Model S Plaid into a NASCAR race and watch it magically transform itself into a flaming puddle of goo, long before the race is over.

Now watch what happens when a 840hp Dodge Demon races a 1,020hp Tesla Model S Plaid:

This is why Dodge is going Electric * Demon vs Plaid Tesla 1/4 Mile Drag Race

The Dodge Demon is a brick of a car (4,255lbs), very nearly as heavy as a Tesla Model S Plaid (4,766lbs).

Who could have ever predicted that the car with more torque and horsepower would win a drag race?

Well I could, for starters, because I accept basic physics. There's no magic going on here. More power wins races... all... the... time.

Turn up the boost to get 1,020hp from that Dodge Demon and watch the lighter car smoke the heavier one, provided that both drivers do their best, every single time.

Can anyone make a battery powered race car as light and powerful as a combustion engine powered race car?

Not on this planet. Not using any current or projected technology.

Does any of that make batteries or battery powered car useless?

Nope. No effect on their utility. However, the physics of batteries imposes hard limitations on range, weight, and carrying capacity.

Again, none of this is about what I want. It's 100% about "what is", and acceptance of "what is".

SpaceNut · 2021-12-24 23:00:38

tahanson43206 wrote:

For SpaceNut .... this report on research toward re-charging while driving could go in many topics ...
I'll start it off here because this topic is active right now, and the Italian research might prove useful in the US.
https://www.msn.com/en-us/autos/motorcy … hp&pc=U531
Italy’s Inductive Charging Highway Project Moves Into Testing
Dustin Wheelen - 10h ago
Never plug in again?
Many European governments continue to expand their electric infrastructure to support a shift away from fossil fuels. As a result, many countries have charging station goals to meet by the next decade. However, Italian automotive group Stellantis believes they can retrofit the current infrastructure for on-the-go EV charging.
Similar to wireless smartphone charging, Stellantis plans to use inductive charging technology to power both parked and in-motion electric vehicles. By installing the company’s Dynamic Wireless Power Transfer (DWPT) tech under the roadway, the system wirelessly charges all-electric vehicles with Stellantis’ special receiver. The project now moves into Phase 3, where the firm will test the charging system at a closed-circuit built near Italy’s A35 autostrada.
external_image
Labeled the Arena del Futuro (Arena of the Future), the project consists of a 1,050-meter (0.65-mile) track powered with a 1-Megawatt DWPT system. In the trial phase, a Fiat 500 Electric and an Iveco E-Way Bus will test the roadway's dynamic inductive charging capabilities. While stationary wireless charging is a step in the right direction, powering cars on the move would be a giant leap for the EV industry.
“This is a cutting-edge solution to provide a concrete answer to the issues of range and charging, both of which customers are concerned about,” noted Stellantis’ Head of Global E-Mobility Anne-Lise Richard. “We’re accelerating our role of defining the mobility of the future and, in this sense, DWPT technology seems to us to be in line with our desire to offer a concrete response to customers’ requirements. Charging vehicles while they are on the move provides clear advantages in terms of charging times and the size of their batteries.”
To provide the utmost safety, the Arena del Futuro also features 5G connectivity and IoT (Internet of Things) technology to ensure optimal communication between the vehicles and roadways. While the project is an exciting prospect for EV owners, Stellantis is investing €30 billion in further electrification and software development. Initial reports may be "more than encouraging", but we can’t wait to see where Stellantis takes the Arena del Futuro next.
This is a technology Louis was forecasting.
I'm glad to see signs someone is investing in trials.
The efficiency of charging while moving may be poor, but if the method saves time for customers, it might end up improving over all efficiency.
(th)

Mars_B4_Moon · 2022-08-11 01:20:09

Chinese automaker Wuling to start selling a 300km range compact EV for less than $5,000

https://www.licarco.com/wuling-hongguang-air-ev

Mars_B4_Moon · 2022-08-26 14:38:06

New Aluminum-Sulfur Battery Tech Offers Full Charging In Under a Minute

https://news.mit.edu/2022/aluminum-sulfur-battery-0824

tahanson43206 · 2022-08-26 17:22:55

For Mars_B4_Moon re #41

Thank you for finding and posting this (to me remarkable) report on research at MIT (and numerous other institutions)!

The new technology is already the basis for a new spinoff company called Avanti, which has licensed the patents to the system, co-founded by Sadoway and Luis Ortiz ’96 ScD ’00, who was also a co-founder of Ambri. “The first order of business for the company is to demonstrate that it works at scale,” Sadoway says, and then subject it to a series of stress tests, including running through hundreds of charging cycles.

Aluminum, Sulfur and a "molten" salt that works at about the boiling point of water, and which destroys dendrites when they try to form is a combination that I would ** think ** will show up on the home market soon.

If there were anyone in the forum membership who is an entrepreneur, this sure looks (to me at least) like a good place to make an investment.

For Mars_B4_Moon ... please keep a watch for any further news on this technology!

(th)

SpaceNut · 2022-08-26 19:35:47

Interesting image of the shot glasses with left to right Aluminum ground up, a liquid sulfur followed by molten salt electrolyte
MIT-Aluminum-Sulfur-Battery-01-PRESS_0.jpg?itok=SIwLGjq1

The salt is not NaCl only but something different and the same with the electrodes.

Abstract on Fast-charging aluminium–chalcogen batteries resistant to dendritic shorting

molten-salt electrolyte composed of NaCl–KCl–AlCl3

It appears to be a liquid battery type...

Calliban · 2022-08-31 16:07:46

I wonder how practical it would be to power a car using some sort of conductor rail embedded in the road? If we assume that the average production car has engine power of 200HP (150kW), then maximum power is about 1/20th that of a subway train. Such a system would need to operate at low voltage to prevent excessive losses to ground. For cost reasons, probably only highways would be elecrified in this way. Because of voltage drop in the rail, transformer stations would be needed every several hundred metres.

RobertDyck · 2022-08-31 20:29:35

Calliban wrote:

I wonder how practical it would be to power a car using some sort of conductor rail embedded in the road?

As I posted in Car-free cities?, we could design the community for the vehicles, rather than trying to use existing roads. If the vehicle requires a rail, make it a rail vehicle, no rubber tires, no concrete road. I suggested an underground subway beneath back lanes for computer driven rail taxis.

An alternative is overhead wires like a trolleybus. Wires use less metal than rails. Overhead wires will not lose power to the ground, and no danger of someone stepping on it. When I was a preschooler, buses like this operated in Winnipeg. Occasionally the conductor poles would fall off the overhead wires; the driver would have to get out and put them back on. Only major down side is trucks with a tall load can not drive on roads with overhead wires.

New Flyer XT60 in Seattle.

Diagram of a 1947-built Pullman Standard model 800 trolleybus, a type still running in Valparaíso (Chile).

kbd512 · 2022-09-01 05:07:19

The major limitation is the energy required to operate the transportation system. Buses do poorly on that metric except when filled to capacity. Most of the time when I see metro buses while driving around town, there are very few people are in them. The exceptions are during rush hour, and then you normally see a fair number of people on board. An electric light rail train system, provided it's actually filled with people over some significant percentage of the time, is about as efficient as you're going to get in any practical sense. Steel-on-steel produces roughly 1/9th the rolling resistance of air-filled rubber tires. We have one light rail system downtown near the stadium and medical area, and those are normally jam-packed with people, which makes them an excellent energy and money trade.

Talk of light rail connecting Austin / Dallas / Fort-Worth / Houston is very popular with local politicians, but if ever approved for construction it's permanently stuck in an endless cycle of litigation (almost entirely frivolous in nature) or approvals from other government agencies (everybody and their dog has to put in their $0.02, despite knowing nothing about it). Years or decades later, dependent upon how you count it, there's still no light rail. If there was light rail, then students, vacationers, and job seekers could freely travel between the cities for reasonable cost. We wouldn't want any of that to happen, though. It'd be nice to have train from at least Omaha to Corpus Christi.

kbd512 · 2022-09-01 11:31:20

They're asking people not to charge their EVs at home in California, and the government estimates that a family with a pair of EVs will roughly quadruple their electricity usage per month.

SpaceNut · 2022-09-01 21:41:43

California EV charging request points to electrical capacity and quite possibly a fire reduction by lowering the vehicle's trying to charge at one time.

kbd512 · 2022-09-02 07:04:57

California is banning gasoline powered cars. Meanwhile, their electrical grid can't take the demand presently placed upon it. Their own estimates say they'll be using about 4X more electricity every day to charge a pair of Tesla EVs at home. You have to be deliberately obtuse not to see the obvious problem there.

Vehicles are not really "objects of affection" for me. They're pretty much tools to be used. However, some are clearly better than others at certain tasks. It's grossly inappropriate to use a dump truck as a "grocery getter", which is why no one does it. The same could be said of mandating electric vehicles in a state experiencing severe electricity shortages due to gross mismanagement under their dumpster fire of a Democrat, Governor Gavin Newsom.

SpaceNut · 2022-09-02 18:41:42

If you think that is bad how about Colorado utility company locks 22,000 thermostats in 90 degree weather due to 'energy emergency'

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