Quote:
Originally Posted by RobertSmalls
I've got three things better.
24KWh/gal - cost equivalence at $0.12/KWh and $3/gal
16KWh/gal - by CO2 equivalence
15KWh/gal - by life cycle energy content
If I understand miket correctly here, he considers direct BTU equivalence to be an EV-inflating number, and he's proposing cost equivalence in ... Saudi Arabia? ... as an EV-deflating figure. Maybe you should use $3/gal vs. the price of electricity for an off-grid solar customer instead. 
I think that's silly, but if you want an arguably justifiable EV-deflating figure, consider the potential of each fuel for heating a house. The house could be equipped with a furnace with an AFUE of .95 (humor me and pretend it could be run on gasoline), or a heat pump with a CoP of 3.5. You arrive at an unflattering, and perhaps unfair, 9KWh/gal.
So there you go, whether you're heating a house, generating electricity, or turning a shaft, electricity is a form of energy that has been "improved" 2-4 times beyond what its KWh content would suggest.
I would encourage everyone to take any direct BTU mpge figures they encounter and divide by two. |
Your conversions sound fine. In some ways the conversion of electricity cost is not really neccesary since we already pay per kwh and electric cars are listed in miles per kwh.
xprize style mpge isnt technically a lie it makes the mileage 'sound better' and the electricity costs for that vehicle 'sound worse'. Its more heinous for C02 conversions i suppose.
I prefer more intuitive metrics. Miles per gallon implies a fixed number of gallons or a fixed gas budget and people driving more or less miles to burn that gas. Gallons per mile implies a fixed distance and people buying enough gas to drive it. I think the second is more accurate. Gallons per 10k miles is probably the best metric for the average person for a cost and environmental standpoint. Whats more usefull this car gets 50mpg or 200gal/10kmi, 35mpg or 285gal/10kmi 20mpg or 500gal/10kmi, 16mpg or 625gal/10kmi. Notice how it would be much easier for someone to know their gas usage and cost than with mpg. Also assuming fixed distances it shows how taking a truck from 16-20 save alot more than taking a car from 35 to 50mpg even though the latter 'sounds better' in mpg.
Secondly what is the cost in saudi arabia?