Electric Truck

[brtecson]

Originally Posted by pvwowk

This leaves us with one technology, battery electric trucks. Granted there are some major issues with range, (about a 100 miles with current battery technology, this is very likely to change). But electricity used in a electric vehicle costs about 1/4 the price of diesel ($0.40/kWh at $4.00/gallon diesel compared to $0.10/kWh electricity).

Your physics is so far off, I don't know where to start.

[brtecson]

Second, a hydrogen fuel cell is far more realistic than a rechargeable battery.

[pvwowk]

Originally Posted by brtecson

Your physics is so far off, I don't know where to start.

Enlighten me. Where did I make a mistake (I just didn't show you all the math).

Hydrogen fuel cells? You know that fuel cells are just a fancy inefficient battery right? It takes electricity to make hydrogen and you only get electricity out. It also requires a whole new multi-trillion dollar infrastructure and fuel cells are currently extremely expensive (with little likelyhood of dropping in price)...

Fuel cells are more political than anything.

[brtecson]

Originally Posted by pvwowk

Enlighten me. Where did I make a mistake (I just didn't show you all the math).

Hydrogen fuel cells? You know that fuel cells are just a fancy inefficient battery right? It takes electricity to make hydrogen and you only get electricity out. It also requires a whole new multi-trillion dollar infrastructure and fuel cells are currently extremely expensive (with little likelyhood of dropping in price)...

Fuel cells are more political than anything.

The beauty of fuel-cells is that you don't lose electrons. You split water and you get two hydrogen atoms and an oxygen atom, then you store them in a container. It isn't really a battery, because you aren't bonding electrons with chemicals. Considering that you dont lose electrons, your complete system is as efficient as the electric motor that you are using, and a typical electromagnetic propulsion is 80% efficient.

With rechargeable batteries, you run electrons through an anode/cathode and you get very few of them to stick. A relatively efficient rechargeable battery is 20% efficient. Of that energy, the 80% efficiency of the motor makes the entire system 16% efficient, one-fifth the efficiency of a hydro fuel cell.

Yes, the infrastructure for hydro fuel cells would be expensive, but more realistic because it only takes minutes to fill up where batteries take several hours to charge. If honda put a 250-mile-worthy fuel cell vehichle in a <3000 lb car, imagine how many miles you could put in a big rig before a refill.

Considering 1hp = 764 watts and you need a couple hundred horsepower to get a rig moving, you need a battery that has a peak potential output over 150,000 watts. With that output, the battery would weigh tens of thousands of pounds.

Originally Posted by pvwowk

But electricity used in a electric vehicle costs about 1/4 the price of diesel ($0.40/kWh at $4.00/gallon diesel compared to $0.10/kWh electricity)

That's correct, but don't forget that a typical electromagnetic propulsion system is 80% efficient and a reciprocating internal combustion engine is less than 10% efficient.

[pvwowk]

Originally Posted by brtecson

The beauty of fuel-cells is that you don't lose electrons. You split water and you get two hydrogen atoms and an oxygen atom, then you store them in a container. It isn't really a battery, because you aren't bonding electrons with chemicals. Considering that you dont lose electrons, your complete system is as efficient as the electric motor that you are using, and a typical electromagnetic propulsion is 80% efficient.

No, they are more like 95% efficient. I'm currently working in the design of an electric motor...

DC series wound motors do get about 80% efficiency, however, ac induction and Brushless DC get about 95% efficiency.

Originally Posted by brtecson

With rechargeable batteries, you run electrons through an anode/cathode and you get very few of them to stick. A relatively efficient rechargeable battery is 20% efficient. Of that energy, the 80% efficiency of the motor makes the entire system 16% efficient, one-fifth the efficiency of a hydro fuel cell.

I don't know where you are getting your numbers, but batteries are MUCH better than 20%. Even lead acid runs between 70-80%. (Granted, lead acids won't work for a truck...) Even lead acids can discharge at rates needed to move a truck, they just won't be able to do it for a long range.

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Newer batteries are more power dense and have higher efficiency.

Originally Posted by brtecson

Yes, the infrastructure for hydro fuel cells would be expensive, but more realistic because it only takes minutes to fill up where batteries take several hours to charge. If honda put a 250-mile-worthy fuel cell vehichle in a <3000 lb car, imagine how many miles you could put in a big rig before a refill.

Considering 1hp = 764 watts and you need a couple hundred horsepower to get a rig moving, you need a battery that has a peak potential output over 150,000 watts. With that output, the battery would weigh tens of thousands of pounds.

With new the new lithium iron phosphate batteries, it will be possible to charge as fast as you can put electricity into the vehicle. It will be limited by the capacity of your plug...

Originally Posted by brtecson

That's correct, but don't forget that a typical electromagnetic propulsion system is 80% efficient and a reciprocating internal combustion engine is less than 10% efficient.

ICEs today are much better than 10%. They are closer to 25% and even get up to 40% during cruise. 80% efficiency I believe is a very close figure if you figure electricity from grid to wheel. 40% efficiency for fuel cells for electricity to wheel.

[L.B.]

Originally Posted by pvwowk

Enlighten me. Where did I make a mistake (I just didn't show you all the math).

Hydrogen fuel cells? You know that fuel cells are just a fancy inefficient battery right? It takes electricity to make hydrogen and you only get electricity out. It also requires a whole new multi-trillion dollar infrastructure and fuel cells are currently extremely expensive (with little likelyhood of dropping in price)...

Fuel cells are more political than anything.

Have you ever considered the "diesel like" engines that run on hydrogen gas?

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Currently used in back up generators. If the hydrogen gas were available. I don't see why this couldn't be a viable option in trucks in the future.

[TLGken]

You could power a truck with a diesel-electric unit like a locomotive, but it would be a weight penalty. The railroads are experimenting with gen-set locomotives to reduce emmisions by running the diesel at constant rpm, when not using all the amperage being produced by the gen-set, the extra electicity is stored in large batteries, using the stored energy to boost the output from the genset.
A truck outfitted like this could use a smaller diesel than trucks use now, using storage batteries to 'launch' the truck from stop signs and help move up hills and grades.
AC vs DC...DC works best for general purpose i.e otr trucks, whereas, AC works best for low speed/constant heavy load.
Trucks using diesel-electric would be several thousand pounds heavier than regular trucks.

The next 10 years of truck powerplant development is going to be very interesting!

[MO family man]

Originally Posted by pvwowk

No, they are more like 95% efficient. I'm currently working in the design of an electric motor...

DC series wound motors do get about 80% efficiency, however, ac induction and Brushless DC get about 95% efficiency.



I don't know where you are getting your numbers, but batteries are MUCH better than 20%. Even lead acid runs between 70-80%. (Granted, lead acids won't work for a truck...) Even lead acids can discharge at rates needed to move a truck, they just won't be able to do it for a long range.

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Newer batteries are more power dense and have higher efficiency.



With new the new lithium iron phosphate batteries, it will be possible to charge as fast as you can put electricity into the vehicle. It will be limited by the capacity of your plug...



ICEs today are much better than 10%. They are closer to 25% and even get up to 40% during cruise. 80% efficiency I believe is a very close figure if you figure electricity from grid to wheel. 40% efficiency for fuel cells for electricity to wheel.

I am so glad we have people with the brains to work this stuff out. I think I got a tumor just reading this.

[Diesel]

Wind Turbine generator electric engines.
Think about it; let’s use a Pete 379 as an example the front grill has a huge surface area for the radiator and engine. Duct it out so the air enters through the grill and into the turbine, and for extra air, put an air scoop on top of the sleeper (think about how the F-117 screen over the air intake wise) and have a wind turbine generator in it and the electric engine below that.
Where the fuel tanks are would be batteries. The batteries would be used for taking off and getting up to speed as well as stop and go traffic.

[MedicineMan]

the problem currently with the truck operating like a train idea is that the electric motors required for the hp and torque are currently too large for use on a truck. you need the motors mounted to the wheels and they are just too large currently but I'm sure this idea will see some use in the future