Prime's Charge Mode - Fast Charge?

Yeah, but this forum is about just one BEV. I'm comparing driving in each mode on the Prime, not to other cars.

 

This map is from 2 years ago, and based upon the average efficiency of the Leaf and Model S.

So the Prime will be better than the 34mpg equivalent CO2 emissions. Either way, a plugin will likely emit less CO2 than an equivalent ICE car in the US. Aside; what is powering Alaska's grid, hydro?

A proposal @austingreen has presented here would use the proceeds of a petroleum tax to reduce payroll(S.S. and Medicare) taxes.

 

but that will give back too much money to higher income earners.

 

The full report can be found here; Life Cycle Electric Vehicle Emissions (2015) | Union of Concerned Scientists. It is newer than the map I posted, and Colorado is now rated 35mpgCO2eq.

My deduction is based solely on the Prime being more efficient than the Leaf and Model S in EV mode. Using less electric means less CO2 emissions from the grid for the same distance.

The Prius sold, IIRC, 110k to 120k units last year(2015), and it is selling less this one. The Corolla sold in the 300k's and the Camry in the 400k's. The F150 did over 700k. With plugin buyers coming from a mix of vehicle types, and not just hybrids or other high efficiency models, it is disingenuous to use the high outlier of the Prius as the measuring stick. At best, it diminishes the impact plugins have in reducing the fleet carbon emissions. At worst, it discourages someone from considering a plugin.

In short, if everyone was buying cars as efficient as the Prius, calling out plugins on not being low enough in carbon emissions is fair, but the majority isn't being such efficient cars. That is why the average new vehicle sold is around 27 to 28 mpg, and actual car is 35mpg. Remember, those averages include the Prii sold.

Depends on the details. Social Security taxes are a regressive tax with a flat rate. As such, they hurt lower income people more, and thus a reduction in the percentage rate they pay helps them more than those with higher incomes. Plus, there is that max income limit on what is taxed, so real high incomes won't benefit greatly.

Or we could go with reducing the payroll tax by a flat dollar amount. Then everyone gets the same reduction amount. Those on the lower end might even get more than they would normally have paid in. This would be like what Alaska pays their residents from the oil profits.

Going through S.S. taxes for reducing the higher fuel cost burden will likely mean less overhead losses than coming up with some other scheme of doing so.

 

To be clear, what I was analyzing was whether it was "better" to run a Prius Prime on gas or on grid power from the point of view of CO2 emissions. It wasn't for any other wider purpose.

 

And I was sharing a source that agreed with your assessment.
And I also took the opportunity to point out that the majority that drive standard ICE cars would likely reduce their CO2 emissions switching to a plugin. They can also do so by getting a plain Prius, but I think most that are willing to take that path have already done so.

 

You mean if you drive an efficient car and make more money a fuel tax will let you keep more of the money you earned? Yes that is exactly what I am after.

Why should the young,poor, and efficient be heavily subsidizing the old (with little means testing) and the people that use a lot of extra fuel. I've heard the politicians say because that is more fair. You know to over tax someone with big student loans so that those retired and rich don't need means testing, or and can drive whatever they want.

Oh wait. Its politics. The old and the inefficient vote. It does not matter what is good for the country. Donald trump pays little or no taxes because he is smart, those that are trying to pay back student loans need to have high medicare and social security taxes to be fair to those that are older, even though they will probably get nothing back.

Get rid of the special deductions for the rich, and lower the tax rates for the rest of us. But all this is off topic. In the US with low oil prices and low gas taxes, people are encouraged to buy less efficient vehicles. If that is what you want we can continue doing it.

 

i'm not ashamed to admit that i didn't understand a word you wrote. but i read it all.

 

How is the CO2 emissions of using an ICE car vs a BEV charged by the grid a different subject than the CO2 emissions of a PHEV in hybrid vs EV mode?

 

Some more math. I been playing with some ICE as a generator numbers and the charge mode/EV Assist concepts based on the Gen. 3 2zr-fxe. Not necessarily how the Prime works.

230grams/kWh BSFC for ICE
Brake specific fuel consumption - Wikipedia
4.5 kW for 80% of EV SoC
estimated 25% electrical generation/ battery charging loss. ( Open for review)
0.5 hour charge mode time

Engine performance technical documentation and graphs (2012)
The renewed 4-Cylinder Engine Series for Toyota Hybrid System
Mr. Shouji ADACHI, Mr. Hikomasa HAGIHARA,
TOYOTA MOTOR CORPORATION, AICHI JAPAN
http://www.mp.haw-hamburg.de/pers/Gheorghiu/Labor/SKM/Anlagen/Prius_2_plus.pdf

Required ICE output for 30 minute charge 6.0 kW (6.0 kW - 25% = 4.5 kW) or 12 kWh.
6 kW x 230g/kWh x 0.5h = 690g fuel consumption
690g = 1.522 lbs = 0.2533 gallons of gas @ 6 lbs/gal. (0.51 gph)
Surprisingly this matches Toyota's stated minimum value for charge mode of 1/4 gallon of gas.

The charging "C" rate is a little over "1" (9 kWh/8.8 kWh). On the high side as 0.35 to 0.7 is what is usually recommended.

If you follow the 12 kW contour to its intersection with the "best efficiency operating line" (fig. 25, right diagram) you see that this point is just a few hundred rpm above "idle speed" just into the 220g/kWh consumption area. In theory the generator would be providing the necessary charge power as calculated above at this point also. The vehicle does not have to be moving at this point. This leaves with increasing engine speed some 40 kW of power in the best efficiency area available to help drive the vehicle by gear or using excess electricity from the generator to power the traction motor.

 

Agreed. Since Toyota has stated they now monitor all the cells in real time and made them more heat resistant, then I wouldn't find it unusual either. Nice analysis @JamesBurke!



Unsupervised!