Technopete, You make some reasonable points here, but I think you are neglecting a few important factors:
1) You have not taken into account the efficiency of getting power into the batteries of the EV. This is listed on one of my links above (for EV1) at 88%. In your estimate you just multiplied the price/kwh at your meter times the amount of kwh you would need in your battery pack to travel 500 miles.
2) Maybe things are different where you live, but here in America as far as I know there are no widespread dynamic electricity pricing programs for retail customers. Its true that it is much less expensive for the utility to make power from baseline plants than it is for them to turn on their inefficient peak load plants, but they only pass that savings on to wholesale customers. My power costs about $0.10/kwh all the time.
There is lots of talk about dynamic power pricing for retail consumers, but so far it has not been implemented on a large scale. I think it would be great, since then you would have an incentive to turn down your air conditioner when the utility is burning coal at those peak load plants, and you could do stuff like charge your EV at night. But for now most people would not get discounted power by charging their EV at night.
So even in your estimate, if you have 88% charging efficiency and $0.10/kwh power, you end up at $22.72. Better than the $60 quoted for IC, but a lot more than the $9 listed in the story.
I take your point about no large-scale off-peak tariff, but have found a link to the PGE site for California http://www.pge.com/tariffs/pdf/E-9.pdf. Presumably these are the sorts of rates that are likely to be widespread if EV's took off generally in the USA, and I would bet they will, especiallly since oil prices are only going one way with increased demand from India and China. PGE quote rates of between 5 and 7 cents for off-peak depending on whether it is summer or winter (though it is difficult to decipher the tariff), so my 5 cents was not an unreasonable guess.
50% worse efficiency that the Tesla Roadster was probably too pessimistic on my part, so I'll redo the calculation with more realistic figures.
Assume a more middle-of-the-range downgrade to the Tesla Roadster efficiency of 20% rather than 50%, giving 133 * 1.2 = 160 KWH consumed by the EV electric motor per 500 miles. 20% downgrade would seem a reasonable guess for a normal saloon car doing your assumed 25 mpg (USA gallon, not imperial gallon), but an SUV would surely be worse.
The 88% efficiency of the charger and battery is not directly relevant. Tesla motors quotes 86% efficiency split between charge and battery i.e. 94% for each. You were talking about the Eestor ultracapacitor which does not have the same inefficiencies as a battery. There is no chemical energy transformation involved with Eestor, just storage of electric charge. It only loses energy as a result of direct heating of the conductors and this should be negligible, so assume 100%. Assume the charger efficiency is 94% as with the Tesla. So now we have 160 / 0.94 = 170 KWH per 500 miles.
Taking 7 cents from PGE above, then 170 KWH * 7 cents = 12 dollars per 500 miles. If your power company refuses to provide an off-peak tariff then it will cost you 10 cents per KWH still and the cost will be 17 dollars.
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Technopete,
You make some reasonable points here, but I think you are neglecting a few important factors:
1) You have not taken into account the efficiency of getting power into the batteries of the EV. This is listed on one of my links above (for EV1) at 88%. In your estimate you just multiplied the price/kwh at your meter times the amount of kwh you would need in your battery pack to travel 500 miles.
2) Maybe things are different where you live, but here in America as far as I know there are no widespread dynamic electricity pricing programs for retail customers. Its true that it is much less expensive for the utility to make power from baseline plants than it is for them to turn on their inefficient peak load plants, but they only pass that savings on to wholesale customers. My power costs about $0.10/kwh all the time.
There is lots of talk about dynamic power pricing for retail consumers, but so far it has not been implemented on a large scale. I think it would be great, since then you would have an incentive to turn down your air conditioner when the utility is burning coal at those peak load plants, and you could do stuff like charge your EV at night. But for now most people would not get discounted power by charging their EV at night.
So even in your estimate, if you have 88% charging efficiency and $0.10/kwh power, you end up at $22.72. Better than the $60 quoted for IC, but a lot more than the $9 listed in the story.
Holly,
I take your point about no large-scale off-peak tariff, but have found a link to the PGE site for California http://www.pge.com/tariffs/pdf/E-9.pdf. Presumably these are the sorts of rates that are likely to be widespread if EV's took off generally in the USA, and I would bet they will, especiallly since oil prices are only going one way with increased demand from India and China. PGE quote rates of between 5 and 7 cents for off-peak depending on whether it is summer or winter (though it is difficult to decipher the tariff), so my 5 cents was not an unreasonable guess.
50% worse efficiency that the Tesla Roadster was probably too pessimistic on my part, so I'll redo the calculation with more realistic figures.
Assume a more middle-of-the-range downgrade to the Tesla Roadster efficiency of 20% rather than 50%, giving 133 * 1.2 = 160 KWH consumed by the EV electric motor per 500 miles. 20% downgrade would seem a reasonable guess for a normal saloon car doing your assumed 25 mpg (USA gallon, not imperial gallon), but an SUV would surely be worse.
The 88% efficiency of the charger and battery is not directly relevant. Tesla motors quotes 86% efficiency split between charge and battery i.e. 94% for each. You were talking about the Eestor ultracapacitor which does not have the same inefficiencies as a battery. There is no chemical energy transformation involved with Eestor, just storage of electric charge. It only loses energy as a result of direct heating of the conductors and this should be negligible, so assume 100%. Assume the charger efficiency is 94% as with the Tesla. So now we have 160 / 0.94 = 170 KWH per 500 miles.
Taking 7 cents from PGE above, then 170 KWH * 7 cents = 12 dollars per 500 miles. If your power company refuses to provide an off-peak tariff then it will cost you 10 cents per KWH still and the cost will be 17 dollars.
Tesla are quoting "less than 2 cents per mile" using the Californian E-9 off-peak rates on their web site http://www.teslamotors.com which is where $9 for 500 miles comes from. In another place on their web site (http://www.teslamotors.com/efficiency/charging_and_batteries.php) Tesla are saying approximately 1 cent per mile (5 dollars per 500 miles).
So I do think you are being unduly pessimistic in assuming the cost will be over 20 dollars, rather than around the 10 dollar mark. !