Still, it goes a long ways towards demonstrating that certain projects = having the potential of providing huge benefits for all of society are = oftentimes beyond the scope of private enterprize alone, the up-front = costs being prohibitive.
Pretty sure Iggy was primarily looking at the situation from an economic = standpoint, specifically, the out-of pocket cost per mile traveled.
And besides, you failed to come up with anything that would quantify a = diference in the total amount of energy that's actually consumed one way = or the other.
An equally valid argument could be made that the cost of gasoline would = be much higher, were it not subsidized..
if they become popular those taxes will be.
Which would be perfectly fine by me....
Eventual failure and the subsequent replacement of engines, axles, = transmissions and so forth is an "operating cost" with fossil fuel = vehicles as well.
As an aside, if recall correctly, probably the biggest problem with = batteries is that US lithium extraction is seriously underdeveloped at = the moment.
For reasons completely apart from battery performance, typically I use = an extension cord and I also have absolutely no desire whatsoever to own = a laptop.
That said, it's pretty hard to argue that overall, battery performance = hasn't improved quite a bit over the last decade or so
Pretty sure it was someplace on a wiki page where it was mentioned that = a decade or so ago, there was quite a bit of fear that battery life = might possibly turn out to be a HUGE problem but that what actuallly = transpired is that in most cases, battery life has greatly exceeded = initial engineering expectations.
Anyways, here's an article probably that lays out the situation fairly = accurately :
(...)
There's that 300 - million - year delay in turning biomass into oil, too. If time is money, that is a hell of a toll.
--Winston
-Still, it goes a long ways towards demonstrating that certain
-projects having the potential of providing huge benefits for all
-of society are oftentimes beyond the scope of private enterprize
-alone, the up-front costs being prohibitive.
We swing back and forth in an ad-hoc manner on public vs private utility ownership, often after the private ones succumb to greed or the public ones to incompetence or corruption. Both types need the carrot plus the stick.
MITRE was the next attempt, on the same model as the RAND Corporation and Sandia Labs, among many others.
jsw
Not even close. A good Otto-cycle engine gets maybe 13% efficiency at near wide-open throttle. At typical mid-throttle operation, it is much worse, maybe 5-8%. A semi-Atkinson cycle engine like in my Honda Civic Hybrid does better at mid-throttle, as does a Diesel by eliminating pumping losses.
So, a standard gas engine is a lot worse than you might imagine.
Most of the electrical gear is WAY more efficient than that, hence small heat sinks and minimal cooling system are needed.
No, the losses in the electrical system are small compared to the incredibly poor efficiency of the typical gas engine. Any time you have the gas pedal less than floored, you are practically driving with the brakes on! Read up on "pumping loss" if you don't believe me.
Then, look at the VAST amount of heat going out the tailpipe, and the significant amount of heat going out the radiator.
Just being able to drive without these massive heat losses gives some idea of the efficiency of electric vehicles.
Compare the KWH energy loaded into the batteries of a typical EV against the BTU content of a tank of gas, you won't believe the numbers!
Jon
Yup, this is Honda's dirty little secret. It looks like they will be replacing a majority of the battery packs in the Honda Civic Hybrid over the course of their 80K mile warranty in the general US, and probably almost all in California with the 100K warranty. Lots of people are troubled with battery degradation and outright failure. One nice feature is the car can still be driven with a failed battery.
The HCH has no cell balancer system, which I think is a big mistake. Not sure if the Prius has this, but they seem to have a lot better luck with their battery system. In the HCH, they are running 100A through Ni-MH D-cells!
Jon
Modern gasoline engines have a maximum thermal efficiency of about 25% to 30% when used to power a car. In other words, even when the engine is operating at its point of maximum thermal efficiency, of the total heat energy released by the gasoline consumed, about 70-75% is rejected as heat without being turned into useful work, i.e. turning the crankshaft. Approximately half of this rejected heat is carried away by the exhaust gases, and half passes through the cylinder walls or cylinder head into the engine cooling system, and is passed to the atmosphere via the coolant system radiator[1]. Some of the work generated is also lost as friction, noise, air turbulence, and work used to turn engine equipment and appliances such as water and oil pumps and the electrical generator, and only about 25-30% of the energy released by the fuel consumed is available to move the vehicle.
At idle, the thermal efficiency is zero since no usable work is being drawn from the engine. At low speeds gasoline engines suffer efficiency losses at small throttle openings from the high turbulence and frictional (head) loss when the incoming air must fight its way around the nearly closed throttle; diesel engines do not suffer this loss because the incoming air is not throttled. At high speeds, efficiency in both types of engine is reduced by pumping and mechanical frictional losses, and the shorter time period within which combustion has to take place. Engine efficiency peaks in most applications at around 75% of rated engine power, which is also the range of greatest engine torque (e.g. in the 2007 Ford Focus, maximum torque of 133 foot-pounds (180 Nm) is obtained at 4,500 RPM, and maximum engine power of 136 brake horsepower (101 kW) is obtained at 6,000 RPM). At all other combinations of engine speed and torque, the thermal efficiency is less than this maximum.
In the past 3-4 years, GDI (Gasoline Direct Injection) increased the efficiency of the engines equipped with this fueling system up to 35%. Currently the technology is available in a wide variety of vehicles ranging from affordable cars from Mazda, Ford and Chevrolet to more expensive cars from BMW, Mercedes-Benz, VAG.
Improving IC Engine Efficiency
Today?s efficiency situation:
FUEL 100%
PUSHING THE PISTONS 35%
OVERCOMING ENGINE FRICTION AND PUMPING THE AIR AND FUEL
(typical US driving condition) 20%
If you're going to correct someone else, try to get your facts right.
Christopher A. Young Learn more about Jesus
No, it does not.
There are essentially two sources of electric power on the planet: Hydroelectric and coal. There are others, but they are very small.
I doubt it. Diesel and gasoline power cars do pretty well. Electric cars need storage batteries, which are notably ineffecient.
Christopher A. Young Learn more about Jesus
Just came back from the CNC Workshop in Ann Arbor, to St. Louis, approx.
525 miles. I did 46 MPG up and back, running at about 70 MPH most of the way. Around town I can get 56 MPG without the air conditioning, but now that it is hotter, about 52 MPG with the A/C. This is a Honda Civic Hybrid.Jon
My Honda hybrid does the same. As soon as you take your foot off the gas, the fuel is cut off and the intake valves are closed, allowing the engine to freewheel with low losses. As you slow for a stop, at 9 MPH the clutch drops out and the engine stops completely. When you take your foot off the brake, the engine is spun up by the assist motor and the valves are engaged. The motor assists acceleration to cover for the woeful power output of the semi-Atkinson cycle engine. The assist motor also absorbs energy to charge the battery during downhill grades and average braking. So, on Honda Hybrids, the brakes usually last the life of the car.
Jon
Why don't we hear more about thorium reactors?
My 1949 Aircraft Powerplant Handbook puts the typical engine output power at 29.5% of the energy in the fuel at cruise, 60% of rated power.
Ya'but does it make one FEEL good?
Not much point to them. They aren't inherently safer than other fuel cycles, they need a neutron source, they breed weapons-grade uranium, just not much of a bargain.
Oh, well, pardon me.
Except for heat and friction loss, gasoline engines, and diesel engines, and steam engines, and, well, everything -- is 100% efficient.
But in an electric car the motor is going to lose energy to heat and friction, and the battery is going to lose energy to heat when it charges, and then again when it discharges, and the speed controller is going to lose energy to heat when it is running, and the inverter in the charger is going to lose energy to heat when it runs, and the wires that take the 'lectricity to your house are going to lose energy to heat and, and --
Learn to think, pal.
And ioncreases the relative efficiency of bunker fired plants.
Boy, for someone who abjures people to read, it's sure interesting that you went and responded to a statement about the energy efficiency of a system with a document that says nothing about the energy efficiency of the system in question.
Unless I missed it, in which case you can correct me by pointing out where that document says how many Joules* you get out of the car for every 1kJ that you put in?
Correction -- _you_ failed to come up with a figure. The best you could come up with was a multicolor graphic from a bureaucrat written for people who don't understand what energy really is.
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