3 fuel types, Diesel, Hydrogen, Electric - Mercedes

[ydnas7]

Mercedes sells the B class in Diesel, Hydrogen and Electric variants
Diesel variant from 3.6l/100 km B 180 CDI BlueEFFICIENCY http://www.mercedes-benz.fr/content/fra ... gines.html" onclick="window.open(this.href);return false;
Hydrogen variant from 0.97 kg H2 /100km http://www.mbusa.com/vcm/MB/DigitalAsse ... S_low2.pdf" onclick="window.open(this.href);return false;
Electric variant from 16.6 kWh /100km http://www.mercedes-benz.fr/content/fra ... ation.html" onclick="window.open(this.href);return false;

How do they compare?

(note for forum mods, keep this separate for a while from other threads until its quiet)

[ydnas7]

1 litre of petrol 9.1 kwh 32.6 mJ
1 litre of diesel-oil 10.0 kwh 35.9 mJ
1 kilogram of hydrogen 33.6 kwh 120.8 mJ

but there are refinery/reformation/electrolysis losses

using refinery losses of 25% (diesel) and reformation losses of 45% (hydrogen)

diesel
3.6 x 35.9 x 1.25 = 161.55 mJ or 45 kWh equivalent

Hydrogen (fossil fuel, bio fuel)
0.97 x 120.8 x 1.45 = 169.90 mJ or 47 kWh equivalent

Hydrogen (electrolysis, non fossil fuel)
0.97 x 54 = 52.4 kWh

so for energy equivalent to propel an EV 100km (16.6kWh)
Diesel 36.9 km
Hydrogen 35.3km (fossil fuel)
Hydrogen 31.6km (electrolysis - non fossil fuel)

ie
Diesel is marginally more efficient than Hydrogen
EV is about 3 x more efficient than hydrogen

[ydnas7]

California requires that publicly subsidized Hydrogen infrastructure must be 33% renewable.
typically that is 1/3 from electrolysis and 2/3 from fossils fuel reformation.
How does that compare to its equivalent in diesel and electricity?

[AndyH]

1 litre of petrol 9.1 kwh 32.6 mJ
1 litre of diesel-oil 10.0 kwh 35.9 mJ
1 kilogram of hydrogen 33.6 kwh 120.8 mJ

but there are refinery/reformation/electrolysis losses

using refinery losses of 25% (diesel) and reformation losses of 45% (hydrogen)

diesel
3.6 x 35.9 x 1.25 = 161.55 mJ or 45 kWh equivalent

Hydrogen (fossil fuel, bio fuel)
0.97 x 120.8 x 1.45 = 169.90 mJ or 47 kWh equivalent

Hydrogen (electrolysis, non fossil fuel)
0.97 x 54 = 52.4 kWh

so for energy equivalent to propel an EV 100km (16.6kWh)
Diesel 36.9 km
Hydrogen 35.3km (fossil fuel)
Hydrogen 31.6km (electrolysis - non fossil fuel)

ie
Diesel is marginally more efficient than Hydrogen
EV is about 3 x more efficient than hydrogen

Seems to me that you might want to re-examine your bounds and comparisons.

Where's the energy that created the oil (and thus the diesel and petrol)? What's the source of energy for the H2 electrolysis and what type of electrolyzer was used? What's the H2 pressure and how is that achieved?

We've had proper well to wheels numbers from the DoE and research labs independent of industry for a couple of years now. Why do you not value those?

[ydnas7]

Both diesel and electricity are more efficient than Hydrogen, Energy for CA hydrogen fuel mix would've traveled 2/3s further in EV + Diesel than compared to H2 Fuel Cell Vehicle.

Put another way, since H2 for Vehicles is more fossil fuel intense than current technology. The pursuit of Hydrogen is drawing vehicles to a fossil fuel dependent future.

[AndyH]

Both diesel and electricity are more efficient than Hydrogen,

Unsupported judgement/opinion, not fact.

Energy for CA hydrogen fuel mix would've traveled 2/3s further in EV + Diesel than compared to H2 Fuel Cell Vehicle.

While a diesel vehicle might provide the range and/or load capability, since the mission profile for this exercise is not defined, this, too, is unsupported judgement/opinion and not fact.

Put another way, since H2 for Vehicles is more fossil fuel intense than current technology. The pursuit of Hydrogen is drawing vehicles to a fossil fuel dependent future.

This appears to be derivative of the above two opinions, and therefore it, too, appears to be unsupported judgment/opinion and not fact.

[ydnas7]

Seems to me that you might want to re-examine your bounds and comparisons.

Where's the energy that created the oil (and thus the diesel and petrol)? What's the source of energy for the H2 electrolysis and what type of electrolyzer was used? What's the H2 pressure and how is that achieved?

We've had proper well to wheels numbers from the DoE and research labs independent of industry for a couple of years now. Why do you not value those?

The diesel is refined from oil.
The H2 electrolysis is renewable electricity, as per SunHydro Station 700bar.

Unless the 'proper' well to wheels numbers are comparing like to like (ie the same vehicle), than there is the magican's distraction and sleight of hand occurring. The clear review of the hydrogen lobby promotes such distortion is explained courtesy of Julian Cox. http://cleantechnica.com/2014/06/04/hyd ... not-clean/" onclick="window.open(this.href);return false;

[AndyH]

Seems to me that you might want to re-examine your bounds and comparisons.

Where's the energy that created the oil (and thus the diesel and petrol)? What's the source of energy for the H2 electrolysis and what type of electrolyzer was used? What's the H2 pressure and how is that achieved?

We've had proper well to wheels numbers from the DoE and research labs independent of industry for a couple of years now. Why do you not value those?

The diesel is refined from oil.
The H2 electrolysis is renewable electricity, as per SunHydro Station 700bar.

Unless the 'proper' well to wheels numbers are comparing like to like (ie the same vehicle), than there is the magican's distraction and sleight of hand occurring. The clear review of the hydrogen lobby promotes such distortion is explained courtesy of Julian Cox. http://cleantechnica.com/2014/06/04/hyd ... not-clean/" onclick="window.open(this.href);return false;

Julian Cox is neither an unbiased nor scientific source. You have included the energy to separate water into hydrogen and oxygen via 'electrolysis' even though we are well aware from the hydrogen thread that there are a number of ways to separate water, including heat, membranes, and alkaline cells. Each has a different efficiency and provides output gas at different pressures. This, in turn, directly changes the energy required to compress the gas to 700 bar. You did not, however, begin with oil's raw materials. The 'efficiency' numbers you provide are useless if you provide a 10,000 year head-start for gasoline and diesel.

[ydnas7]

All measurements were in l/100km using NEDC. They are measurements.

Fact - new Nissan LEAF can go 124mile on NEDC.
reality - nobody drives a car NEDC style until they are stranded.

The point is, comparing equivalent, like per like, Hydrogen is more fossil intense than either diesel or electricity

[AndyH]

All measurements were in l/100km using NEDC. They are measurements.

Fact - new Nissan LEAF can go 124mile on NEDC.
reality - nobody drives a car NEDC style until they are stranded.

The point is, comparing equivalent, like per like, Hydrogen is more fossil intense than either diesel or electricity

While you've done a great job repeating what you've already typed, it doesn't appear that you really understand that you're not using the same energy calculation starting point for all of the fuels, and I see no indication that you're listening to my feedback. While you say that 'like per like' is important, you haven't yet actually done it and don't seem to grok that something really large is missing. Here - let me help with that - compliments of the American Association for the Advancement of Science:

http://www.eurekalert.org/pub_releases/ ... 102603.php

Oct. 27, 2003 - A staggering 98 tons of prehistoric, buried plant material - that's 196,000 pounds - is required to produce each gallon of gasoline we burn in our cars, SUVs, trucks and other vehicles, according to a study conducted at the University of Utah.
"Can you imagine loading 40 acres worth of wheat - stalks, roots and all - into the tank of your car or SUV every 20 miles?" asks ecologist Jeff Dukes, whose study will be published in the November issue of the journal Climatic Change.

But that's how much ancient plant matter had to be buried millions of years ago and converted by pressure, heat and time into oil to produce one gallon of gas, Dukes concluded.

Feel free to tally the amount of water and solar energy embodied in 98 tons of biomass that will become a gallon of gasoline. I look forward to your more correct energy balance. Feel free to ignore the energy it took to heat and compress the biomass into crude for now.