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Fossil Fuels Are 40% of Freight Shipping Tonnage, but Half Its Fuel Use

cleantechnica.com

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Re: Fossil Fuels Are 40% of Freight Shipping Tonnage, but Half Its Fuel Use

#31

Post by lukevp »

bryanlarsen wrote: post #27

The top graph makes it seem much more dramatic than it is. Maritime shipping is very efficient, and consists of a very small fraction of overall petroleum usage. Road transportation uses about 20x as much fuel as ocean shipping, planes use about 2x as much, and trains about the same amount. The typical rule of thumb is that about 40% of the energy in a barrel of petroleum is lost before it goes into your gas tank. An…

Why is the EV better? Because electricity transmission is more efficient than gas? What about the losses in the electricity transmission and the batteries and the conversion to motive force in the motor? Is it way less than that 40%? And wouldn’t there be more than 0% losses because refinery -> power plant shipping?

I’m pro EV by the way, I just want to understand your point better. Being able to go all the way to transportation using clean energy is an obvious benefit of EVs. The “dirty electricity” angle is less obvious to me.

Re: Fossil Fuels Are 40% of Freight Shipping Tonnage, but Half Its Fuel Use

#32

Post by bruce511 »

lukevp wrote: post #31
bryanlarsen wrote: post #27

The top graph makes it seem much more dramatic than it is. Maritime shipping is very efficient, and consists of a very small fraction of overall petroleum usage. Road transportation uses about 20x as much fuel as ocean shipping, planes use about 2x as much, and trains about the same amount. The typical rule of thumb is that about 40% of the energy in a barrel of petroleum is lost before it goes into your gas tank. An…

Why is the EV better? Because electricity transmission is more efficient than gas? What about the losses in the electricity transmission and the batteries and the conversion to motive force in the motor? Is it way less than that 40%? And wouldn’t there be more than 0% losses because refinery -> power plant shipping? I’m pro EV by the way, I just want to understand your point better. Being able to go all the way to tr…

In an EV about 90% of the energy used is converted into motion. About 10% goes to heat. [1][3]

In an ICE engine about 30% of the energy becomes motion. About 70% is heat.[2]

In other words electric motors are about 3 times more efficient than ICE.

[1] an interesting side effect of this is that in cold climates you can't just harvest waste heat to heat the cabin (or batteries. ) So you end up using some battery energy if you need heat.

[2] ICE motors vary in effeciency a lot. 20-30% is typical. The Carnot formula comes into play here.

[3] because there is so little heat generated, the cooling systems (EVs still have them) are much smaller. And simpler (for example, no fan, 'cause there's no heat when standing still.)

Re: Fossil Fuels Are 40% of Freight Shipping Tonnage, but Half Its Fuel Use

#33

Post by tsss »

bruce511 wrote: post #32
lukevp wrote: post #31

Earlier quoted context omitted.

Why is the EV better? Because electricity transmission is more efficient than gas? What about the losses in the electricity transmission and the batteries and the conversion to motive force in the motor? Is it way less than that 40%? And wouldn’t there be more than 0% losses because refinery -> power plant shipping? I’m pro EV by the way, I just want to understand your point better. Being able to go all the way to tr…

In an EV about 90% of the energy used is converted into motion. About 10% goes to heat. [1][3] In an ICE engine about 30% of the energy becomes motion. About 70% is heat.[2] In other words electric motors are about 3 times more efficient than ICE. [1] an interesting side effect of this is that in cold climates you can't just harvest waste heat to heat the cabin (or batteries. ) So you end up using some battery energy…

Who cares about motor efficiency when you can only take 10% as much fuel. At the end of the day, cost is the only metric that matters.

Re: Fossil Fuels Are 40% of Freight Shipping Tonnage, but Half Its Fuel Use

#34

Post by bruce511 »

lukevp wrote: post #31
bryanlarsen wrote: post #27

The top graph makes it seem much more dramatic than it is. Maritime shipping is very efficient, and consists of a very small fraction of overall petroleum usage. Road transportation uses about 20x as much fuel as ocean shipping, planes use about 2x as much, and trains about the same amount. The typical rule of thumb is that about 40% of the energy in a barrel of petroleum is lost before it goes into your gas tank. An…

Why is the EV better? Because electricity transmission is more efficient than gas? What about the losses in the electricity transmission and the batteries and the conversion to motive force in the motor? Is it way less than that 40%? And wouldn’t there be more than 0% losses because refinery -> power plant shipping? I’m pro EV by the way, I just want to understand your point better. Being able to go all the way to tr…

>> The “dirty electricity” angle is less obvious to me.

A power plant typically gets about 60% of energy from a fossil source. A car does about 30%. So even if the electricity comes from say coal, it's still more efficient than buying gas in a car engine.

Of course, these days, it's likely that a substantial portion (up to 100% in some cases) is not "fossil electricity" but rather comes from solar, wind, hydro etc. Ie "clean" electricity.

Re: Fossil Fuels Are 40% of Freight Shipping Tonnage, but Half Its Fuel Use

#35

Post by hedora »

The headline is only surprising if shipping is the majority of fuel use.

It isn’t. In the limit, if it were 100% of fuel use, then we’d be burning 1.2 gallons of fossil fuel to deliver 1 gallon, which clearly wouldn’t work.

A much better question is “what percentage of the embodied carbon for this good is from freight shipping”? The answer is almost always very low because last mile shipping dominates, and so does manufacturing the item. For fossil fuel, those things dominate, and so does the step where the customer burns the fuel.

Basically, the entire article is confused because it doesn’t start with the fossil fuel equivalent of Amdahl’s Law.

Re: Fossil Fuels Are 40% of Freight Shipping Tonnage, but Half Its Fuel Use

#36

Post by bruce511 »

tsss wrote: post #33
bruce511 wrote: post #32

Earlier quoted context omitted.

In an EV about 90% of the energy used is converted into motion. About 10% goes to heat. [1][3] In an ICE engine about 30% of the energy becomes motion. About 70% is heat.[2] In other words electric motors are about 3 times more efficient than ICE. [1] an interesting side effect of this is that in cold climates you can't just harvest waste heat to heat the cabin (or batteries. ) So you end up using some battery energy…

Who cares about motor efficiency when you can only take 10% as much fuel. At the end of the day, cost is the only metric that matters.

The cost of EV energy (to the driver) is about half that of the cost of gas energy. And that's if you buy electricity at charging stations [1].

If you charge at home it gets less. If you have solar at home it approaches zero.

Yes, the cost of the car itself is a factor, but even there prices are dropping all the time.

>> when you can only take 10% as much fuel

effeciency makes all the difference when we discuss % of fuel. 90% of 100 mj is the same as 30% of 300 mj. So already the "fuel" can be 66% less. Generally though the raw amount of mj isn't a very important number. A better measure (which takes effeciency, and tank size into account) is "range". But even that is somewhat meaningless. At some point range is "enough". For daily commutes that may be 50 miles. For long-distance it might be 500 miles.

In only a very few cases would a pickup with 2000 mile range be more useful than one with 1000 mile range.

Plus you can also factor in maintenance costs. The cost of ownership of an ev, from a service and maintenance point of view is a lot lower.

[1] ymmv somewhat. Although electricity prices vary a lot, so do gas prices. The 50% saving (at worst) is a pretty good rule of thumb though.

Re: Fossil Fuels Are 40% of Freight Shipping Tonnage, but Half Its Fuel Use

#37

Post by [deleted] »

tsss wrote: post #33
bruce511 wrote: post #32

Earlier quoted context omitted.

In an EV about 90% of the energy used is converted into motion. About 10% goes to heat. [1][3] In an ICE engine about 30% of the energy becomes motion. About 70% is heat.[2] In other words electric motors are about 3 times more efficient than ICE. [1] an interesting side effect of this is that in cold climates you can't just harvest waste heat to heat the cabin (or batteries. ) So you end up using some battery energy…

Who cares about motor efficiency when you can only take 10% as much fuel. At the end of the day, cost is the only metric that matters.

[deleted]

Re: Fossil Fuels Are 40% of Freight Shipping Tonnage, but Half Its Fuel Use

#38

Post by kortilla »

lukevp wrote: post #31
bryanlarsen wrote: post #27

The top graph makes it seem much more dramatic than it is. Maritime shipping is very efficient, and consists of a very small fraction of overall petroleum usage. Road transportation uses about 20x as much fuel as ocean shipping, planes use about 2x as much, and trains about the same amount. The typical rule of thumb is that about 40% of the energy in a barrel of petroleum is lost before it goes into your gas tank. An…

Why is the EV better? Because electricity transmission is more efficient than gas? What about the losses in the electricity transmission and the batteries and the conversion to motive force in the motor? Is it way less than that 40%? And wouldn’t there be more than 0% losses because refinery -> power plant shipping? I’m pro EV by the way, I just want to understand your point better. Being able to go all the way to tr…

Grid loss is maybe 5%.

The important driving factor is that generation becomes more efficient when you can use natural gas to turn turbines directly and then capture the waste heat to boil water and turn turbines with steam. This is called combined cycle if you want to google it to learn more.

Another thought exercise, if generating electricity with fossil fuels wasn’t more efficient at scale, why would we bother building a grid in the first place? Every house would just have a gas generator.

Re: Fossil Fuels Are 40% of Freight Shipping Tonnage, but Half Its Fuel Use

#39

Post by ectoloph »

lukevp wrote: post #31
bryanlarsen wrote: post #27

The top graph makes it seem much more dramatic than it is. Maritime shipping is very efficient, and consists of a very small fraction of overall petroleum usage. Road transportation uses about 20x as much fuel as ocean shipping, planes use about 2x as much, and trains about the same amount. The typical rule of thumb is that about 40% of the energy in a barrel of petroleum is lost before it goes into your gas tank. An…

Why is the EV better? Because electricity transmission is more efficient than gas? What about the losses in the electricity transmission and the batteries and the conversion to motive force in the motor? Is it way less than that 40%? And wouldn’t there be more than 0% losses because refinery -> power plant shipping? I’m pro EV by the way, I just want to understand your point better. Being able to go all the way to tr…

As I understand it, it's a mix of factors.

Charging Lithium, and converting to motive force in motors are both pretty efficient. (Both >90%).

An ICE vehicle has an upper limit on efficiency that is lower than what a modern fossil fuel plant can reach, and the ICE is less likely to sit at peak efficiency all the time. The world record, set this year was 48%. Previously, it was 41%.

Power plants are much more likely to be kept at or near their peak efficiency and have the space for systems like heat recovery (to recapture waste heat) and emissions controls. For a gas turbine plant, I think the record is ~64% sustained.

Re: Fossil Fuels Are 40% of Freight Shipping Tonnage, but Half Its Fuel Use

#40

Post by olivermuty »

tsss wrote: post #33
bruce511 wrote: post #32

Earlier quoted context omitted.

In an EV about 90% of the energy used is converted into motion. About 10% goes to heat. [1][3] In an ICE engine about 30% of the energy becomes motion. About 70% is heat.[2] In other words electric motors are about 3 times more efficient than ICE. [1] an interesting side effect of this is that in cold climates you can't just harvest waste heat to heat the cabin (or batteries. ) So you end up using some battery energy…

Who cares about motor efficiency when you can only take 10% as much fuel. At the end of the day, cost is the only metric that matters.

My xpeng g9 goes about 570km in summer. Less in winter, like 480 maybe. Longest range ICE i had was a mercedes wagon that went 1050km on one tank of gas.

Filling the wagon today would cost me like 170 euro. Filling my xpeng happens overnight and is about 7-9 euro depending on grid pricing.

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