They already do. I fly electric model aitrcarft, and the state of the art power output of a modern system is about a brake horspower per pound of power train.
Now that is about a 4 minute flight at that power level admittedly,. but I can certainly fly an average model for an hour on modern batteries. FLY it. Not have it crawling along the ground.
The energy density is ceratinly good enough for at least one project car powered by similar batteries to have been built that had a 300 mile range and out performed a porsche. I think they paid $250k for the power pack though,. :-)
Not quite. But given the appalling efficiency and weight of IC engines, overall it comes close.
State of the art electric powertrains cannot yet match the power to weight of e.g. a racing 5cc model aircraft engine and fuel tank, but they are within 50% of it easily. They exceed 'cooking' IC engine installations easily.
Diesel is about 13 KWH/kg.
My Lithium batteries achieve about 150W/kg. Bigger ones achieve 350Wh/kg.
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if you factor in the overall powertrain efficiencies, and the weight of the IC option, things get far far closer.
Since a diesel engine is, at best, 30% efficient in road going mode whereas a top quality electric motor is 90%, you end up with - in terms of output power - 3.9Kw/kg of diesel and 315Wh/kg for the lithium battery.
Now if you look at power train weights...A 200bhp diesel car probably has about 60% iof a 1.5 tonne weight in terms of all the gubbins associated with making it go...to whit.
Engine Exhaust stystem Gearbox Cooling system Transmission
and so on. ALL of which can be replaced with 4 custom motors, one on each wheel and say a fairly lightweight bank of electronics to drive them.
Thats 900kg of gubbins and about 60kg of fuel, being replaced by 600kg of battery, and four electric motors.
I am seeing about 2Kw/lb or 4Kw per kg (roughly) in terms of motor weight in the stuff I am aquainted with.
So to do 150KW of motors for our 200bhp car, we need about another 38kg of motor(s).
so 900kg for the diesel, 638 kg for the electric, for similar range and power output.
The difference is the diesel power train currently costs about 10,000 quid and refills in 5 minutes, whereas the lithium.electric currently would cost about half a million quid and takes an hour to refill.
Various lihium manufacturers are working to get cost and recharge times down. Irs te reverse of what we do in the model aircraft world - there we accept an hour to recharge and 5 minutes of flight - cars need 5 minutes of recharge and 5-10 hours of travel...
So although its not there yet, the overall engineering of lithium electric cars is possible and competive performance- and range- wise with an average car engine.
The issues are safety, cost, and recharge times.
As I said before Drivel is usually wrong, but in this case randomly, he is not.
I have never driven a car with a 500 mile range. 300 is average, and I have had some that were less thahn 200, and a few that were over 300. None will crack 400 even, let alone 500.
Read my other post. If you factor in the totality of the power train, things look exceptionally rosy for a lithium electric. Its as good as or better than an IC engine. Leccy motors are VERY light and do not need complex gearboxes. If you add in regenerative braking they are even better...
Where it would realluy score is in the urban/subuirban area - a small car with lightweight body, that does at best 50-100 miles a day and gets recharged every night. On off peak electriciity. But is still capable of
90mph and 300 miles on a good day.
This is technically feasible RIGHT NOW. Its not comnmercially viable YET.
Also the overall weight of car is less with an electric car. The IC engines is big and heavy along with transmission and fuel tank. It has to drag all that weight around.
An electric car is a small wheel in hub motor and a set of batteries and no heavy suspension and heavy body to support it either. The power to weight ratio of an electric beats an IC.
In some case they also offer the manufacturer experince with electric transmissions that will pay dividends when the batteries they really need become available.
About 30 % more than the energy you get out in a fuel cell, and about 3 times what you would get out in an internal combustion engine running on hydrogen.
Actually it would be cheaper than oil or gas at todays prices IF two things were to happen
- it wasn't so completely sutrounded with sfatey regulations that are way in excess of what is required for any other industrial activity pro rata to te risk to life involved
- it wasn't effectively taxed with respet to the disposal of its waste material way above what is fair compared with other indistrial activities.
People have been very emotional about nuclear power. i've heard ministers claiming blatint lies to be facts...
Fortunately the game has switched from 'can we afford to take the risk' to 'can we afford NOT to take the risk'
And te short answr is , no we can't. There is a greater risk to UK society from not going ahead with more nuclear plant than from going ahead with it.
Not unless you use nuclear energy or wind turbines or some such there ain't...and there is bugger all non fossil electrc capacity in our grid at the moment/
Try telling that to know-it-alls here. Boy do they think oddly. Richard Cranium, bless him, I know he tries, thinks only the IC engine is worth and all the rest is bunkum. Sad I know. A few were on about hydrogen being produced for next to nothing....as if. That is the holy grail.
With the exception of (the majority of) UK nuclear plants that have specific problems with load changes down and then rapidly up, the installed generating capacity in the UK (even the 500's and 660's coal plants installed in the 60's and 70's) are perfectly capable of being shut down or run on very reduced load overnight and return relatively rapidly to load next morning. They don't like doing it and it is wasteful in some respects - hence why some power stations have in the past bid into the system at zero cost (they got paid the system marginal rate) which works right up until the point at which the load drops unexpectedly, the system marginal bid is zero and nobody gets paid - it has happened!
Batteries on their own will not make a car move, the motor and control system has to be factored in. In any case 250kg is considerably above the weight of even some 15 year old engine gearbox combinations (around the 1.6 litre mark)
It looks to me that an ic engined car achieving 50mpg uses about
0.64kWhr(t)/km. You suggest a battery powered car will manage on a tenth of this, as electrical energy drawn from a battery, seems a tad optimistic.
Ignoring embedded energy in the machines and battery, do we have an overall figure for grid electricity conversion from a thermal plant? What about charge/discharge efficiency?
So to get your 0.062kWhr(e)/km out of the battery what do we need to put in to an average coal plant?
Is it 0.062 divided by 80% battery loss? divided by overall grid efficiency of 33%? => 0.24kWhr(t)/km? Or are there worse losses somewhere in between?
Even so I doubt the appeal will be in the overall efficiency because the proposed new thermal electricity plants will have a very cheap fuel. Also spreading their generating cost over as many hours as possible will favour off peak loading by battery charging.
Blair was on about energy from unstable countries. First the UK must use less energy, and not waste so much as we do. That should be implemented ASAP along with wind, tide, wave, solar. Then it is a matter of sorting out the rest. Nuclear is a quick fix (in politicians eyes). The rest can be mixed, but nuclear way down the list.
But IC engines are getting better all the time and will continue to improve. It's not so long ago all diesels were cast iron, rough, noisy and slow - not so today.
Well yes. If you take state of the art anything and compare it with cooking then what do you expect? You're also assuming the electric power train will improve, but not the IC one.
Err, rather a large gap to overcome? We're not talking about a few percent but an order of some 37 times.
Better at only 12 times... But your 30% figure is rather out of date.
Again, you're not comparing like for like. All those heavy components need not be so heavy. They're built down to a cost. Use the extra cost of the hybrid power train on lightweight materials and the results will be rather different.
Predicting the future is risky. And we've been promised cheap electric cars since I was a kid. But for every development of these we get similar improvements with IC engines.
And, of course, how you generate the electricity to charge them. That is the big fly in the ointment since charging any battery is an inefficient process.
Excuse me? He reckoned there were existing batteries that weighed the same and had the same energy capacity as a tank of petrol. This is just plain nonsense.
How you convert that stored energy into useful power is neither hear nor there.
If you want to predict that there will be batteries in the future that will do, I could equally as well predict there will be some form of IC engine developed that gets to 80% efficiency. But I'd be guessing, same as you.
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