BioFuel

[Satanic Mechanic]

Ijuin,
Yes converting gasoline to electricity is not very effecient.  The reason why we call it a hybrid is the best of both worlds of gasoline/diesel and electric propulsion.  We are trying to migrate people from ICE (Internal Combustion Engine) to the E.V.  The easiest way and cheapest way for car manufacturers to do this is through the hybrid.  Eventually we will be driving Electric Vehicles but it is a long road ahead.
One of the reasons why we are not driving electric vehicles now is car manufacturers do not want to invest in battery technology and battery manufacturing.  They know that whoever builds batteries first is going to lose money.  The battery technology is out there, like Lithium Polymer cells, this is the "300 Mile Battery" that everyone is looking for.
In the early 1990's the DoE, the U.S. Big 3 auto makers, battery companies and universities go together to form the U.S. Battery Consortium ( or Company, forgot what the C stood for).  Lots of money went into research and development, some advances were made but one of the car makers, Chrysler if I remember correctly, withdrew from the group which caused its collapse.  After one auto maker left, the rest followed.  They do not want to spend the money on battery production, they want to buy it off the shelf with no R&D costs.

SM

[Satanic Mechanic]

It can be more efficiently transmitted, it can be stored, and it can be used directly in portable engines such as  in cars.

Unfortuantely storing hydrogen is very expensive.  Metal Hydride tanks cost a lot of money. 
I have read many books from Hydrogen pioneers like Billings and I always wanted to make a hydrogen car.

SM

[DonPMitchell]

Yes, but storing electricity is even more expensive.  It's probably cheaper to store bulk hydrogen as LH2.

[ijuin]

Ijuin,

The following information comes from hazy memories of Year 12 physics, and may be out of date or simply incorrect.  But this is the basis for my idea

The transfer of energy from petrol to motion was something like 25 -35% efficient.  The transfer in a generator was in the order of 60 -70%(although if you could use a jet APU, I believe that's in the low nineties!), and an electric motor about 80%.  So if these figures are right, you could expect to have a more efficient conversion in a hybrid.

You are suggesting the conversion chain fuel-->electricity-->motion. However, unless you're using a fuel cell, then whence comes the motion to turn the generator? In a hybrid, it comes from the petrol motor! Thus, a hybrid has the conversion chain fuel-->motion-->electricity-->motion. The "35% efficiency" is the efficiency from gasoline to crankshaft. The 70% efficiency for electricity is from crankshaft to power line, NOT from fuel to power line. What's turning your car's internal generator, if not a petrol motor?

[Ispaced]

With a little search I found this site, it must be the one I surfed before
because the links on the page are outlined like I have. But it does show
it's cost, not bad less than a buck a gallon. Here's the page!

"http://journeytoforever.org/biodiesel_make.html"

[Johno]

You are suggesting the conversion chain fuel-->electricity-->motion. However, unless you're using a fuel cell, then whence comes the motion to turn the generator? In a hybrid, it comes from the petrol motor! Thus, a hybrid has the conversion chain fuel-->motion-->electricity-->motion. The "35% efficiency" is the efficiency from gasoline to crankshaft. The 70% efficiency for electricity is from crankshaft to power line, NOT from fuel to power line. What's turning your car's internal generator, if not a petrol motor?

I think I failed to communicate three things.
1)  A mechanical transmission system (especially automatic) is terribly inefficient.  If this can be eliminated and replaced with an electrical transmission system, there are immense efficiency benefits. 

2) A petrol engine needs to be overpowered to overcome the inertia of mechanical gears.  If you can eliminate these, you can use a smaller petrol engine.

3) If you are using a mechanical gearbox, your engine must be throttled to control the speed of the vehicle, and a petrol engine can only be truly efficient at certain speeds (cruising).  In a hybrid, you can always run the engine at its optimum speed, because the speed of the vehicle is controlled independently.

[ijuin]

So then you are implying that the conversion of motion to electricity and back to motion again has LESS loss than the transmission of crankshaft motion directly to the wheels? Do you have any numbers on transmission losses in a typical automatic transmission?

[Satanic Mechanic]

Yes, but storing electricity is even more expensive.  It's probably cheaper to store bulk hydrogen as LH2.

It is funny you mention that, storing electricity.  Last Friday I was talking to the president of the local utility and the subject came up about their fuel cell research.  He told me the best way to store electricity is in very large pools of water called lakes.    When they need more electricity to meet demand, they let more water through the turbines at the dams.I know Don that you live on the otherside of the state and that are state is blessed with an abundance of hydroelectric power. 
Back to the hydrogen- I also remember about reading about replacing transmission lines with hydrogen transmission lines.  Less losses and low maintenace on the pipes.

SM

[Satanic Mechanic]

To answer some questions:
A gasoline APU, burning regular unleaded has an effiecency of 13%.  It is higher for diesel.  The idea for using an APU is the motor, if ran, can run at it most efficient range.  When I was working on the project, we developed a "voltage clamp" in which the voltage was constant, the RPM were fixed and we met all the emission standards.

An automatic transmission is not used because you lose a minimum of 20% going through the torque converter.  The losses through a standard transmission are very small.  One way around the automatic transmission system is a direct drive system, the motor or motors are connected to the axle.

SM

[DonPMitchell]

Yes, we have huge hydroelectric resources in Washington state.  The question every summer is what to do with the water:

1. Save it

2. Sell electricity to California

3. Open the fish ladders for the salmon to get upstream

The general concensus among Washington residents is that salmon rate higher than Californians. 

[spacecat27]

Lots of 'thread drift' here- but it's informative!
Leads to multiple questions, keeping in mind I'm in the service & maintenance loop and quite a few decades removed from the R&D loop---
Is it still correct to say AC motors are favored in EV's for their higher efficiency- and is that efficiency of a magnitude that it justifies the inherent losses of going DC to AC through an inverter?  I guess the 'big picture' question is- (with a nod to Tesla) are AC motors always more efficient than DC?  I was under the impression that DC motors have come a long way, recalling the bushless 'pancake' motors I once worked with on big ol' Honeywell tape drives (yeah, that dates me! 

All this leads to some real 'ancient history' questions--- I guess because of their higher efficiency, AC motors have been used in aircraft electrical systems for many years- even the Mercury spacecraft ran DC from its batteries through low-current inverters to drive AC ventilation fans.  ( The only 'new' thing about the inverter I worked on for SkyLab was that it was 'high-current' for its time.)  The AC 'standard' for aircraft electrics seems to be 400 Hz, 3-phase; but I've never found anybody who could explain how and why that came about?  Have wondered if it was just a product of high-RPM alternators or APU's?  Even old Air Force guys from prop days didn't have an answer other than to say, 'well, that's what we've always used.'

[DonPMitchell]

This looks like good work.  Apparently some species of algae are almost 50 percent oil!

http://www1.eere.energy.gov/biomass/pdfs/biodiesel_from_algae.pdf

[Ispaced]

Thanks that will keep me busy!

[Satanic Mechanic]

Lots of 'thread drift' here- but it's informative!
Leads to multiple questions, keeping in mind I'm in the service & maintenance loop and quite a few decades removed from the R&D loop---
Is it still correct to say AC motors are favored in EV's for their higher efficiency- and is that efficiency of a magnitude that it justifies the inherent losses of going DC to AC through an inverter?  I guess the 'big picture' question is- (with a nod to Tesla) are AC motors always more efficient than DC?  I was under the impression that DC motors have come a long way, recalling the bushless 'pancake' motors I once worked with on big ol' Honeywell tape drives (yeah, that dates me! 

All this leads to some real 'ancient history' questions--- I guess because of their higher efficiency, AC motors have been used in aircraft electrical systems for many years- even the Mercury spacecraft ran DC from its batteries through low-current inverters to drive AC ventilation fans.  ( The only 'new' thing about the inverter I worked on for SkyLab was that it was 'high-current' for its time.)  The AC 'standard' for aircraft electrics seems to be 400 Hz, 3-phase; but I've never found anybody who could explain how and why that came about?  Have wondered if it was just a product of high-RPM alternators or APU's?  Even old Air Force guys from prop days didn't have an answer other than to say, 'well, that's what we've always used.'

E.V. question- Yes the AC inductive motor is the most efficient.  When I took my high voltage systems class in college, I learned there were over twenty different types of motors.  We had to remember there voltage, current and torque curves for a test.

400Hz question- I always wondered that too.  I looked it up and found this: http://www.aerospaceweb.org/question/electronics/q0219.shtml
That makes sense since they are trying to save weight with lighter power supplies.  On a side note, in the late 90's car makers tried to get away from the 12V system and go with a 48V or 60V system for smaller gauge wires.

SM

[spacecat27]

Thanks, SM-
Funny, awhile back when I was snooping around for an answer on the 400 Hz, I came across that same link but remember on the day I looked at it, only the first paragraph and photo displayed (server problems?  who knows?) so I didn't get the complete explanation.

I've been aware of the push for higher voltage in automotives & such since the late '90's.  I think it's happening slower than was expected because of the manufacturing changes it would place on the big accessory market- stereos and all-- and mechanics have not been happy about it cause face it, if you're leaning across a fender and brush a positive terminal, you really have to be hot and sweaty to feel 12V.  48 or 60 would knock you on your tail!