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Old 03-26-2018, 03:48 PM   #1 (permalink)
hayden55
Master EcoModder
 
Join Date: Dec 2010
Location: USA
Posts: 1,168

Sport Utility Prius - '10 Toyota Prius II
90 day: 52.98 mpg (US)

300k Sequoia 4WD - '01 Toyota Sequoia Limited 4wd
90 day: 20.19 mpg (US)
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Total Power efficiency between a Hybrid and EV? Who wins?

If you've considered the entire circuit for which energy made it to your gas tank or battery which would be more efficient in my home state of good ole ARkansas? EV or Hybrid? Imagine if energy was charged in price by how efficiently it was utilized at its final destination vs its total exergy available at its source of production.
To the numbers:
For Arkansas power production goes:
Coal: 44% of production @ 38.5% thermal efficiency. (local plants efficiency)
Natty: 26% of production @ 55% thermal efficiency. (averaged number for ngcc )
Nuclear: 24% of production @ 30% thermal efficiency.
Hydro: 3% of production @ 90% efficiency.
Total production efficiency average for Arkansas: 41.14%
Power Grid efficiency: ~92%.
Power to the source: 37.8488%
EV Charging efficiency: 85% (avg between long period charging in hot and cold weather and 120v and 240v charging)
Power efficiency to the battery: 32.17148%
Kwh/mi: 0.28kWh (using 2018 Bolt EV numbers).
Meaning It took around 740Wh to move the EV one mile including efficiency losses of power production.

Now onto the Gasoline car:
Efficiency of factory Supply Electricity: 37.8488% (from above)
Refining gallon of gas: 88.1% efficiency (4kWh = 10.568 kWh at source needed to produce a gallon at the EPA's number of 33.7 kWh in a gallon of gasoline).
Transport: 80,000 pound tanker (11,000 gallons of gas at 6.21lb/gal) ~ 6mpg typically 100 miles (diesel ~ 37.95 kWh/gal) = 16 2/3 gallons of diesel. = 632.5kWh used. Also a full load was considered 11,000 gallons.
Math to get your gallon to the pump: 11,000 gallons produced: 116,248kWh used for production + 632.5kWh for transport.
Production Energy per gallon: 10.6255kWh/ gallon. = 68.47% total efficiency of production.
2018 Ioniq EPA 58mpg: 581kWh per mile.
So that means it takes 848.6 Wh of energy production to move your Ioniq one mile on average.

So the bummer is all the taxes and transportation fees on the gallon of gas, but it looks like the EV is about 14.7% more efficient to drive. A far cry from the "EVs are free" picture the world is trying to paint. An upside though is our area has little to none free charging, but the cost per mile is pretty nice on EVs. Green thumb wise if you are that guy it looks like for my area to break even with the EV you only need to average 67 mpg! lol Still very impressive considering the average mode of fossil fuel transportation not being very efficient
If it wasn't so politically uncorrect to burn gasoline and people realized that most areas are entirely coal or nuclear powered it would probably be a different picture on the subject right now, but its interesting to see in my home state with our abundance of Natty gas and its inherent efficiency of production.
Mazda is the first of the big manufacturers to decide to lower its energy use per mile by creating a more thermally efficient power plant forgoing electrics so it will be interesting to see how the world shapes up in the next five years.
As always if you see any mistakes or have any gripes leave some comments below.

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Last edited by hayden55; 03-26-2018 at 03:58 PM..
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