It requires energy to accelerate a mass to a given velocity,it also requires energy to de- celebrate a mass. In the case of a motor vehicle that can be through friction losses, airodynamic losses or energy converted to heat by braking. Now if we want to accelerate that mass again, as in the real world of motor vehicles, we have to provide more energy Where does that energy come from? Simples.
Braking a motor vehicle uses energy.
Braking a motor vehicle uses energy.
Hybrids recover energy during braking. I can't imagine that the Leaf does not do this too.
G²
Once one has defined the losses and resistances to movement, by the shape and weight of the vehicle, the only cheap way to improve the range of a battery powered, or Hybrid vehicle is to "recover" energy that would otherwise be wasted during slowing down and/or braking.
If an existing hybrid manages to recover 50% of the energy that would other wise be wasted in slowing down and stores that at an efficiency of 70% and then re-uses that recovered/stored energy at an efficiency of 75%, then the total recovery to re-use efficiency will be around 26%. That's from guesses on my part, I have not seen data from the manufacturers.
If one could get the recovery and storage and reuse efficiencies upto 90% each, then the total recovery to re-use efficency could be around 73%.
That's a massive increase from ~26%
I suspect the manufacturers are constantly looking at the cheapest ways to get from 26% to 73%.
I further suspect it will takes decades to get close and maybe they will never get to that target.
In the meantime, accelerating up to the required cruising speed is expending useful work.
Cruising along with minimal losses is useful work.
Slowing down and braking is wasting fuel/energy, unless that waste can be reduced by energy recovery.
If an existing hybrid manages to recover 50% of the energy that would other wise be wasted in slowing down and stores that at an efficiency of 70% and then re-uses that recovered/stored energy at an efficiency of 75%, then the total recovery to re-use efficiency will be around 26%. That's from guesses on my part, I have not seen data from the manufacturers.
If one could get the recovery and storage and reuse efficiencies upto 90% each, then the total recovery to re-use efficency could be around 73%.
That's a massive increase from ~26%
I suspect the manufacturers are constantly looking at the cheapest ways to get from 26% to 73%.
I further suspect it will takes decades to get close and maybe they will never get to that target.
In the meantime, accelerating up to the required cruising speed is expending useful work.
Cruising along with minimal losses is useful work.
Slowing down and braking is wasting fuel/energy, unless that waste can be reduced by energy recovery.
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Bill, Andrew is correct. You came looking for a semantic argument. Driving doesn't waste energy, as driving is what we want to do with the energy, slowing down bins off energy as wasted heat and excess friction. You can argue the toss all you like over energy vs fuel as a semantic point, but it won't make you right.
Finally you get it right.
The second law, she is a biatch. Whatever you do, you lose. Otherwise you would have a car you could charge once a month.
From a physics viewpoint that is very wrong. Braking a vehicle converts kinetic energy into something else, generally heat. You cannot 'use' energy.
Using petrol in an otto engine has 30% efficiency 70% is heat.
Air resistance converts to heat and stands for approx 50% of the (30% useful petrol energy). Road friction 30% and 20% is start/stop in city traffic.
Cruising in 75km/h is much more efficient than driving in 130 km/h since the efficient air resistance is increasing with speed^2.
Air resistance converts to heat and stands for approx 50% of the (30% useful petrol energy). Road friction 30% and 20% is start/stop in city traffic.
Cruising in 75km/h is much more efficient than driving in 130 km/h since the efficient air resistance is increasing with speed^2.
Braking converts kinetic energy (that was chemical potential (aka fuel) 5 mins ago) into heat. Accelerating to increase speed again uses more fuel.
The fuel you're talking about is the fuel you burnt 5 minutes ago to get up to speed.
The fuel Bill is talking about is the fuel you need to burn to get up to speed again.
Chris
For the OP...the Leaf is an all electric vehicle without a combustion engine. To range extend it you need to configure an auxiliary battery pack of either the same system voltage as the Leaf or interface a lower voltage auxiliary pack through a DC-DC converter. In either case the key will be to find someplace for this pack to reside. It is hard to envision a solution which does not either seriously degrade the utility of the vehicle by filling all spaces with batteries, or by hitching a trailer behind it. In all cases given the complexity of safely engineering a large lithium ion pack a serious element of risk will result. It would undoubtedly be cheaper to drive the Leaf to the nearest Tesla dealer and trade it on a Model S!
Returning now to our previous entertainment:
Bill: "Ïs too!"
Andrew: "Is not!"
Bill: "Ün-huh!"
Andrew: "Nuh-uh!"
...
Returning now to our previous entertainment:
Bill: "Ïs too!"
Andrew: "Is not!"
Bill: "Ün-huh!"
Andrew: "Nuh-uh!"
...
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