Posted on 02/08/2022 9:05:40 AM PST by rktman
“And yes, regenerative braking recovers some power spent, “
70%.
Nice post.
“My bad, “motor braking”. An EV requires constant input on the ‘gas’ pedal, or the vehicle slows pretty quickly because without input power, the motors want to stop - “
Actually, the regen circuit is a little more complicate. But which EV’s have no regen as you earlier claimed?
“Disadvantage EV. Requiring such massive battery packs, most EVs are HEAVIER than their ICE counterparts (or even mid-size pickups) meaning there’s MORE friction to overcome”
Less friction. The drive train on a conventional car loses over 20% due to friction.
You are missing the point that combustion engines are first law of thermodynamics machines they will NEVER be as efficient as second law machines which am.electric motor is. Every person who passed freshman level physics can do the equations to prove this.
The energy to move a tesla model S over a one mile distance is on average 250 watt hours.
A similarly sized car such as a S60 Volvo that gets a combined 30 mpg takes 1113
watt hours to go the same distance.
The math:
Petrol is 114,000 btu to a US gallon
114,000/30 is 3800 btu per mile
There is 3414 btu to one kilowatt hour
3800/3414 = 1113
The model S is actually a larger car in cubic foot of passager space so the smaller ICE car still loses BADLY.
My S60 gets 30mpg on the motorway with some as in less than 30% city motoring in full city mode its 28 or less mpg even with the start stop mild hybrid system running. It has a 48V belt start system so it never idles it stops the motor at every stop light and fires up when you step off tbe breaks.
“EV. Requiring such massive battery packs, most EVs are HEAVIER than their ICE counterparts”
EV’s regen 70% of the energy needed to accelerate that extra weight.
Advantage EV.
“Every person who passed freshman level physics can do the equations to prove this.”
Thus, the problem here.
The wear and tear of a EV designated as a postal vehicle would be different than the EV that is used as a commuter car.
” it stops the motor at every stop light and fires up when you step off tbe breaks.”
I had a Ford Explorer loaner. It restarts even while holding the brake. AC demand?
The first time it happened I thought the car behind had bumped me.
I have no idea how long a battery would run. They need to do a stimulation of using an EV as a postal vehicle. Estimate how long then battery would last before it needs to be replaced.
So what? Eating seaweed is a lot more efficient than pork.
“I have no idea how long a battery would run. “
Hundreds of thousand miles and decades.
“So what? Eating seaweed is a lot more efficient than pork.”
Non Sequitur
Mine turns back on when the battery volts drop below 11.5 if you are running the heater it waits till that voltage point then will run at high idle till volts hit 14.5 then auto off again. With the A.c.in auto mode it will stay off till the temp out of the vebtst rises what seems to be about 5 degrees then start to run the compressor then shut down again in a cycle that is on for a minute off for three to five with the air on recirculation. In the dead of super summer I turn off the auto stop feature since it cycles off and on every two minutes most of the time when creeping in traffic.individual stops are under a min anyways its dead halt...creep for 50 feet dead halt for 60 seconds creep I used to drive a manual in traffic like this it was infuriating.
That’s the intelligent response?
Point one for any primary source of energy the second law machine will always use it more efficiently.
Example one. A natural gas combined cycle thermal powerplant can approach 70% fuel to HVAC busbar eff. This is very near the theoretical maximum and no internal combustion engine on earth comes close to that level of btu to the joule or watt hour choose a unit. The very best internal combustion engine on earth is a large ship diesel it weights over 2500 tons turns at 100 rpm or less and has a fuel to prop efficiency of just over 50%
The transmission losses from HVAC busbar over 200km of grid through HVAC to 240v transformer and to a class C wall outlet is 3% This means for every 100,000 btu of natural gas you burn at the powerplant you put 65100 btu to the pack of a tesla S or 19.068 kwh which is 19068 watt hours that energy will take a tesla S 76.274 miles
That same 100,000 btu in petrol will take a smaller S60 Volvo already one of the more efficient cars 26.31 miles given 30mpg combined, 114,000 btu gal petrol.
The second point is if you have solar panels on your garage you can fill up a tesla in sunny Texas with twelve 450 watt panels from zero to full in a single 12 hour day at this latitude our shortest day is in January its exacly 10 hours of full sun not imcluding civil.twilight our longest day is in June its 14 hours and 18 min of daylight. No one drives 300+ miles per day every day not even taxi drivers or uber guys. Most people charge a tesla every night to replace the 10 or less kWh they used that day. Why less than 10? Because the avg daily driven distance for the avg American is undee 40 miles roind trip the NHTSA keeps up with this via state registration reported mileages. This means it woukf take two panels in 12 hours pf daylight to replace what the average American uses in the kind of sun we get in Texas. This location has 220+ days of full sun per year.
Having an EV and panels is equal to having a petrol refinery in your back yard. No one has an oil well, a three way gas oil water separator, a fractional distillation tower, followed by fluidic hydrocracker followed by a desulferization unit to meet 15ppm or less in sulfur for 87 RON motor fuel absolutely no one anywhere has that in their backyard let alone back 40. I very few might have a functioning natural gas well for those lucky few they would still need a full EPA approved desulfur and dehydrogensulfide gas clean up system, down to less than 15ppm sulfur and 5ppm or less H2S then 10,000 psi compressors and carbon fiber tanks to hold the methane or a full LNG train with minus 230C rated cryo compressors expanders and double wall insulated cryo storage tanks with all the Hazmat permits to run that LNG train plus storage that can BLVE explode with the force of a small tactical nuke.
Much cheaper and easier to out up.a.dozen panels at $68 each when bought in bulk. Panels can had for 15 cents a watt capacity I have posed a number of times sources for them as soon as the supply chain clears up.
EVs are idiotic for the USA. We have loads more oil and gas reserves to exploit and use for transportation. It is the green nut cases and Democrats who hold us back on this exploration and drilling. So directly burning them in internal combustion engines, instead of burning them (coal) to make electricity for EVs. We have loads of wide open spaces where EVs make no sense. Such as Nebraska and Montana. Most of our Western states. Southern States.
63% of our electricity comes from coal and natural gas, and add another 3% for burning “petroleum”. https://en.wikipedia.org/wiki/Electricity_sector_of_the_United_States#Electricity_generation
China, Korea and Japan are better suited for EVs. Just about all their cities are super congested with traffic. EVs excel in such stop and go traffic. They do not have the vast gas and oil reserves that we have in America. So they can use hydroelectric, solar, wind, nukes and burn coal to send electricity for their EVs if they like. US is a much different case.
Western Europe is densely populated, so better suited for EVs than America. With its vast oil and gas production, Russia should ban all EVs.
Never use wiki its always bunk.
Go right to the people paid to monitor what you are seeking.
https://www.eia.gov/tools/faqs/faq.php?id=427&t=3
Petroleum is 0.4% not even a rounding error in the USA.
I wish people would stop beating the coal horse to death. In the USA coal is under 20% total generated. Coal is equal to nukes OR renewables. Remember this is verified actual megawatt hours delivered to the grid not theoretical. Put this way a EV on the grid in the USA is on average 40% powered by nuclear power and renewables nether of which release air pollution another 40% is clean burning natural gas thats orders of magnitude cleaner coming off a stack at a gas turbine vs a diesel or petrol car on the roads. So 80% of the avg USA EV is zero or low emissions. Less than 20% is coal.
Energy source Billion kWh Share of total
Natural gas 1,624 40.5%
Coal 773 19.3%
Petroleum (total) 17 0.4%
Petroleum liquids 10 0.2%
Petroleum coke 8 0.2%
Nuclear 790 19.7%
Renewables (total) 792 19.8%
It is more efficient to burn natural gas in a modern combined cycle plant and send that electricity to an EV than it is to burn the same amount of gas directly in a ICE engine. The math is solid on it there is a mumber of studies on Google scholar should one look for them.
You will never fuel your internal combustion engine from your back yard legally. No one has an oil well, plus all the petrochemical industry to refine fuel to anywhere close to the minimum legal standards, not even if you grew your own corn made ethanol and distilled it to 95% yourself fedgov will still say no without thousands of.dollars per year in permits and taxes. You can very easily cleanly and cheaply fuel an EV from your roof top. Four panels in the sunny parts of the USA more than covers the yearly average mileage of a person in the USA. If you.dedicated those panels just to.charging no grid tie, inverter or transfer breaker is needed just moderate voltage DC cables. That would be dumb since tbe panels would spin your meter back wards when not pluged in charging the EV.
See #76
“It is more efficient to burn natural gas in a modern combined cycle plant and send that electricity to an EV than it is to burn the same amount of gas directly in a ICE engine. The math is solid on it there is a mumber of studies on Google scholar should one look for them.”
Total bullshit! And if I am wrong then the numbers are very close. Anyways moot because we are rarely burning compressed natural gas in ICE though I would like to see more. This would be ideal for USPS trucks. UPS and Amazon delivery.
EVs are good for nations with lots of stop and go traffic. Same for hybrids. In the USA we don’t need them, though they would be good for congested cities as taxis or second household vehicles.
The large town next to me had a propane refueling station I used to go to to refill my BBQ tanks. They were running many of their town vehicles on compressed NG and propane. Unfortunately they stopped this 10 years ago.
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