Puppeteer

Author Topic: Electric car question  (Read 750 times)

38ac

  • Hero Member
  • *****
  • Posts: 2201
    • View Profile
Electric car question
« on: December 27, 2022, 02:00:09 PM »
OK gang, Im not really the mathematical type and certainly have a very light hold on electrical stuff. Have a question that's pretty ambiguous but has to be that way for now.
I keep a little old car around for my local trips. Currently a 2006 Ford Focus. Gets 25MPG or so on short trips and 35 on the road. I will be replacing it in the next year or so and considering a full electric,, not a hybred. Reason being I have a near endless supply of waste oil, plenty of India clones and ST heads. On to my question. Would it be a logical thought to think that a gallon of oil generating power to charge the car would roughly equate to a miles per gallon if used as engine fuel?
Collector and horder of about anything diesel

sirpedrosa

  • Hero Member
  • *****
  • Posts: 807
  • 21NOV2019 - Finally I hear that sound... again
    • View Profile
Re: Electric car question
« Reply #1 on: December 27, 2022, 02:50:12 PM »
Butch, Gentles

Butch... you want to turn to a toaster?

Hellloooo!

I cant belive you gona change LEF profile.  ;D ;D ;D ;D

Im loocking foorward to see that!

It gona be like this! Take a loock!

Have a nice year.
VP

 ;D ;D ;D ;D ;D ;D
By order of firing up:
Bernard 18A - 1968 (mama's water pump - year of my birth)
Petter PAZ1 - Jun 1967, 3HP, sn 416xxxx
Petter PAZ1 - Nov 1979, 3HP, sn 425xxxx
Lister 12/2 - 12651227, the pearl!
Deutz MAH 914, 1952 - Wating for the Zündfix to fire up.

38ac

  • Hero Member
  • *****
  • Posts: 2201
    • View Profile
Re: Electric car question
« Reply #2 on: December 27, 2022, 03:20:02 PM »
If I can generate the charging current with waste oil in an efficient manner its something to consider, If not then I will stay with dino. It does not make sence to me to have the cost pf two systems of power in one vehicle aka hybrid, I would want straight electric,, I think???
Collector and horder of about anything diesel

broncodriver99

  • Sr. Member
  • ****
  • Posts: 431
    • View Profile
Re: Electric car question
« Reply #3 on: December 27, 2022, 04:02:42 PM »
Would it be a logical thought to think that a gallon of oil generating power to charge the car would roughly equate to a miles per gallon if used as engine fuel?

I am sure it is calculable but you would need quite a bit of information to do so.

Is it going to be efficient, I highly doubt it. The most realistic numbers I have seen from power grid operators is that about 35% of the energy in the fuel used to generate electricity actually makes it to one's home with transmission/conversion losses. Their plants operate at close to 100% efficiency.

A listeroid is going to be somewhere around 30-35% efficient at converting fuel energy into mechanical energy, a cheap gen head will be somewhere in the realm of 70% efficient at converting mechanical energy into electrical energy, depending on your battery charger it will be somewhere around 60% efficient at taking said electricity and converting it and charging the batteries with charging losses as I don't believe batteries accept anywhere near 100% of the energy provided during charging.

If you could figure out how much waste oil it takes for you to generate 1kwh of electricity then you may be able to pull the charging data on a specific vehicle and extrapolate an average charging cost and divide that by the average mileage you would get from a charge.

That is one of the reasons the big push on EV charging is for solar, it is about the only way that makes any economical sense. If you were to find an old diesel VW Rabbit or pickup or an old Mecedes diesel and run it on waste oil that would get you orders of magnitude further with less effort.

32 coupe

  • Hero Member
  • *****
  • Posts: 528
  • "Doc Johnson" on call !
    • View Profile
Re: Electric car question
« Reply #4 on: December 27, 2022, 04:08:37 PM »
Short answer.....no


Metro 6/1 turning a ST 7.5 KW gen head
Changfa 1115 turning a ST 15 KW gen head
Ashwamegh 2/25
John Deere 110 TBL
New Holland TC 30

"I was sitting here reading this thinking what an idiot you are until I realized it was one of my earlier posts !"

BruceM

  • Hero Member
  • *****
  • Posts: 3029
    • View Profile
Re: Electric car question
« Reply #5 on: December 27, 2022, 06:14:24 PM »
I think we are painting a darker picture than is warranted.
Using the same fuel in a diesel engine car will only result in 30% efficiency as well, so the IC engine loss is a wash; you lose it either way so it does not count.

A 65% charge/battery charge combined efficiency is often reported.  So the only question is whether that 35% loss is really a loss considering that the fuel is essentially free.  I'd say so.

This also lends itself to adding some solar so that in sunny parts of the year, the oil can be conserved and CO2 reduction is provided. 





38ac

  • Hero Member
  • *****
  • Posts: 2201
    • View Profile
Re: Electric car question
« Reply #6 on: December 27, 2022, 06:21:10 PM »
On the average week I drive the car about a 100 miles.

Once more plenty of assumption and guess required but if I had lets say a Chevy Volt and used a 16/2 Listeroid and ST head to power the charger would anyone like to take a stab at gallons of fuel per week?  Believe me I know I am way out in left field with  theoreticals here but I'm surely not smart enough to do anything but pure guess.
« Last Edit: December 27, 2022, 06:22:42 PM by 38ac »
Collector and horder of about anything diesel

broncodriver99

  • Sr. Member
  • ****
  • Posts: 431
    • View Profile
Re: Electric car question
« Reply #7 on: December 27, 2022, 06:37:37 PM »
Let's look at it this way.

Lets say 1 gallon of fuel = 10 miles of energy conent.

Burning one gallon of fuel in an IC engine vehicle would net 3-3.5 miles of travel.

Burning one gallon in a listeroid would net 3-3.5 miles worth of mechanical energy, then that 3-3.5 miles of mechanical energy is converted into electricity at 70% input effeciency netting 2.1-2.45 miles worth of electricity, then that 2.1-2.45 miles of electrical energy is converted by a charger which has losses as does the process of battery absortion (65% efficiency) so you end up with 1.365-1.5925 miles of travel from that same gallon of fuel. So, 13.5-16% efficiency.

That's a pretty grim reality. Even if everything about the scenario were free, engines, gen head, charger, waste oil, time , maintnance, etc. it is still an extremely poor return for something that has better than double the efficiency when used directly in an IC engine. Like I said that is why the big push for EV charging is solar(and wind) as the perception is that it is free/green. Really though those have capital costs as well as environmental costs and a payback period that is really much longer than anyone wants to admit.

I'm not knocking EVs I just dont think they are the Rainbows and Unicorns that many want to make them out to be. I think that continued investment in IC development as well as alternatives could net just as good or higher gains when EVERYTHING is factored into the equation.

broncodriver99

  • Sr. Member
  • ****
  • Posts: 431
    • View Profile
Re: Electric car question
« Reply #8 on: December 27, 2022, 06:41:32 PM »
On the average week I drive the car about a 100 miles.

Once more plenty of assumption and guess required but if I had lets say a Chevy Volt and used a 16/2 Listeroid and ST head to power the charger would anyone like to take a stab at gallons of fuel per week?  Believe me I know I am way out in left field with  theoreticals here but I'm surely not smart enough to do anything but pure guess.

My best guess would be to find the fuel efficiency of a similar vehicle with an IC engine and double it at a minimum. That would probably get you in the ballpark of the fuel required to charge an EV. And that is being very generous to the home built charging setup.

38ac

  • Hero Member
  • *****
  • Posts: 2201
    • View Profile
Re: Electric car question
« Reply #9 on: December 27, 2022, 07:01:02 PM »
Thanks for that.  So if my little car uses 4 gallons of gasoline to go 100 miles and the electric car is similar weight n size then I would need 8-10? gallons of waste oil to charge the battery for same 100 miles?  Or have I missed something? As I said earlier Im pretty badly challenged when these tbings get past simple, And I still have to deal with the WMO wear in the engine
« Last Edit: December 27, 2022, 07:02:35 PM by 38ac »
Collector and horder of about anything diesel

broncodriver99

  • Sr. Member
  • ****
  • Posts: 431
    • View Profile
Re: Electric car question
« Reply #10 on: December 27, 2022, 07:29:32 PM »
Yes, 8-10 gallons would be my best guess. It's one of those if you already have the facilities and fuel source to produce the electricity and don't mind some maintenece costs and time then why not. Once you factor in the added wear as you said due to the WMO as well as normal wear and tear and oil changes then you have an expense that really may offset any feasibility of the situation.

Another thing I would look at is charge rate. Many of the EVs that come with little 120v chargers are meant to be charged say overnight. So 8-10 hours up to 20 hours on some vehicles at a low rate. You have to step up to one of the higher output chargers to get anything in the 2-4 hour range and I am not sure what the current requirements are for those, they may exceed what you can produce with a CS twin. So, another concern would be run times on your charging setup.

I am not sure if short charging EVs has the detrimental battery effects that it does on most other batteries. If it is something you can do a few hours a week here and there then I would consider that nonproblematic. But if it is something that you need to do for 8-20? hours at a time then I would start to look at that as a chore.

BruceM

  • Hero Member
  • *****
  • Posts: 3029
    • View Profile
Re: Electric car question
« Reply #11 on: December 27, 2022, 07:31:08 PM »
You only need to fudge some additional losses over the standard 35% battery/charger losses for additional ST head losses.  So maybe 55% of total losses over direct diesel car use.  You do gain back energy for regenerative breaking, which can be significant for in town driving.

So if you needed 4 gallons of gas for the car's weekly drive,  you should be around 5-6 gallons of diesel. (Used oil.)

Lithium batteries are way higher in charge/discharge efficiency, over 80%; the 65% figure includes this and charger losses.  38ac's range needs are so low that he can easily stay in the highest efficiency range of battery charge.

Charge efficiency improves at lower charge rates, and you will be operating in the higher efficiency range. 

Bronco is thinking this was a lead acid battery?   There is no penalty for partial charges in lithium batteries, only some penalty for full charging some lithium ion/cobalt batteries.  Not so much for LFP.






« Last Edit: December 27, 2022, 07:35:41 PM by BruceM »

broncodriver99

  • Sr. Member
  • ****
  • Posts: 431
    • View Profile
Re: Electric car question
« Reply #12 on: December 27, 2022, 07:37:54 PM »
You only need to fudge some additional losses over the standard 35% battery/charger losses for additional ST head losses. 

I disagree. AC generators, consumer level heads anyway are in the 70-80% efficiency range. And that is assuming that an ST head is on par with a western produced high quality gen head.

38ac

  • Hero Member
  • *****
  • Posts: 2201
    • View Profile
Re: Electric car question
« Reply #13 on: December 27, 2022, 07:50:38 PM »
While not free the engines, drives and heads are already here. I'm not far enough into this to know about slow or fast chargers. However if I can fully load a 6/1 with a slow charger that would be close to a quart per hour. If it had to run 12 hours for the charge that would be 3 gallons, guessing that a 6/1 isn't going to charge the battery for 100 miles of driving in 12 hours?? As you can see, my thought patterns don't follow science, Electricity is all seat of the pants with me.
Collector and horder of about anything diesel

BruceM

  • Hero Member
  • *****
  • Posts: 3029
    • View Profile
Re: Electric car question
« Reply #14 on: December 27, 2022, 08:09:31 PM »
https://www.caranddriver.com/features/a36062942/evs-explained-charging-losses/

This is a bit more current on actual charger/battery losses.... and they are seeing about 20% losses for charger and battery, which is way better than starting at 35%. 

ST head efficiency is more likely around 80% despite the simplicity and high THD. So add another 20% to the 80% for charger and battery losses, and it's still 60% efficiency.

So 6 gallons of diesel for 4 gallons of gas mileage is reasonable.  Cold weather is another story; the present LFP batteries need heating in cold temperatures which eats into the charge power/efficiency dramatically.  But if the fuel is free that isn't a deal breaker.

The 6/1 is pretty small for car battery charging. 
Many Chevy Bolt drivers see 3.7 miles per kilowatt hour.  Assuming 3Kwh per hour of 6/1 charging, 12 hours of charging would be 12x3kwh =36 kwhrs x 3.7= 133 miles.  If you estimate your full load fuel use for those 12 hours at 0.33 gallons per hour thats 5.2 gallons for those driven 133 miles.   133 mi/5.2 gallons= 25.5 mpg using the CS as generator for an EV.

This is consistent with my previous estimate.  The fuel consumption at 0.33 gallons per hour at 3KW is something you can check yourself as this may be off.  Plug in your own number and see what you get.