What does Toyota see in "Fool" Cells?

[JRP3]

He's also still taking the 65% efficient FCV figure from Toyota as if it's accurate in the real world, but not using the most efficient NG generating plant numbers. I'd bet Toyota is using their best number, not average.

Using 60% generating efficiency and a 90% charging efficiency, (my car charges between 92-94% efficiency now), gives us a 43.8% efficiency today.

 

[TheTalkingMule]

My thought has always been that if hydrogen production efficiency is 70% and fuel cell efficiency is 65%, then all you have to worry about is taking hydrogen down to a small enough container and then back up safely and reliably. That can't be too difficult for mankind to figure out within 10 years or so.

Put a 10kW systemn on your roof, top off your garage-based hydrogen production every day and then feed excess to the grid. So long as you can produce and store your hydrogen onsite, then all you have to do is come up with a way to get it into the vehicle. Shouldn't be the hardest thing in the world, hydrogen is fairly flexible.

Why would you ever bother with all this transmission and distribution nonsense? Just make hydrogen and put it in your car.

 

[Johan]

My thought has always been that if hydrogen production efficiency is 70% and fuel cell efficiency is 65%, then all you have to worry about is taking hydrogen down to a small enough container and then back up safely and reliably. That can't be too difficult for mankind to figure out within 10 years or so.

Put a 10kW systemn on your roof, top off your garage-based hydrogen production every day and then feed excess to the grid. So long as you can produce and store your hydrogen onsite, then all you have to do is come up with a way to get it into the vehicle. Shouldn't be the hardest thing in the world, hydrogen is fairly flexible.

Why would you ever bother with all this transmission and distribution nonsense? Just make hydrogen and put it in your car.

PV-generated electricity -> hydrogen -> fuel cell -> electricity -> electric motor

vs

PV-generated electricity -> battery -> electric motor

Which is simpler? Why bother with the added complexity especially in your own garage and your own solar? The only theoretic merit of FCV is exactly the possibilty of refueling at a station.

 

[Reykjavik]

Okay, as you insist on looking at the efficiency more closely, let's look at the chain from well to wheel. And for good measure, let's look at the current tech vs overseeable future-tech.

Electric car, current situation:

Natural gas distribution to power plant: 96.5%
Power plant efficiency: 42.45%
Power grid distribution: 93.5%
Charger efficiency: 85%
EV efficiency: 90%

Total efficiency: 29.3%

FCV, current situation:

Natural gas distribution to steam reformation plant: 96.5%
Hydrogen production: 70% efficiency
Hydrogen compression: 90% efficiency
Hydrogen distribution: 90% efficiency
Hydrogen fueling: 98% efficiency
FCV efficiency: 65%

Total efficiency: 34.8%
...
So, my numbers suggest that when starting with natural gas, FCVs are more efficient than EVs, both now and in the overseeable future.

Natural gas distribution to steam reformation plant: 96.5%
Hydrogen production: 70% efficiency
Fuel cell power station with cogeneration: 85%
Power grid distribution: 93.5%
Charger efficiency: 85%
EV efficiency: 90%

Total efficiency: 41%

If you have a fuel cell power plant that is stationary, you can run a turbine using the waste heat to generate electricity, which can bring your efficiency up as high as 85%. I wasn't able to find real world numbers for the efficiency, but if you assume all of your numbers are accurate, you need just over 72% efficiency at the fuel cell power plant for the EV to be more efficient overall.

 

[JRP3]

Why would you ever bother with all this transmission and distribution nonsense? Just make hydrogen and put it in your car.

Why bother with a highly explosive element that is difficult to contain and takes complex and expensive machinery to create, store, and compress, when what you really want is electricity? Daytime solar charging at work means you use the PV output directly, at home you'd need a battery bank of course if you aren't there during the day. Since the average daily miles driven is less than 40 miles figure about a 12kWh battery bank at home, plus or minus depending on your needs. We know Tesla is charging $280/kwh retail for the price difference between the 60 and 85 kwh cars so similar pricing would put that 12kWh pack at $3,360. Since energy density is less important for stationary storage you could easily use a less energy dense and less expensive battery. I'd be willing to bet the equivalent equipment needed to produce, store, and compress a similar amount of hydrogen would be quite a bit more, and less durable since you have high pressure seals that wear out and leak and a high power compressor that needs maintenance.

 

[jerry33]

Which is simpler? Why bother with the added complexity especially in your own garage and your own solar? The only theoretic merit of FCV is exactly the possibilty of refueling at a station.

How is that a benefit? I thought that would be a reason to avoid FCVs.

 

[richkae]

Why would you use a 42.45% efficiency number for natural gas powerplants?

If you are comparing against a theoretical hydrogen production system that doesn't exist you should at least compare with the best natural gas combined cycle powerplants that exist now.
Instead of building hydrogen boondoggle plants, we could just build more efficient natural gas powerplants.
This is already happening as new 60% efficient plants are built:
GE Secures $1.2bn in New Orders for Environmental Leader
Irsching Power Station - Wikipedia, the free encyclopedia

Over a 10 year period from 2001 to 2010 California has improved its natural gas generation efficiency by 31% by replacing old plants with new ones.
That will continue and hydrogen will never catch up to that.

Plus in the future natural gas will allow us to improve the 93.5% efficiency cited for the distribution system by making more smaller plants closer to the consumers of the electricity.

 

[Johan]

How is that a benefit? I thought that would be a reason to avoid FCVs.

It is IMO but one could argue that it's one of the theoretically positive aspects of hydrogen, that BEVs lack.

 

[anticitizen13.7]

PV-generated electricity -> hydrogen -> fuel cell -> electricity -> electric motor

vs

PV-generated electricity -> battery -> electric motor

Which is simpler? Why bother with the added complexity especially in your own garage and your own solar? The only theoretic merit of FCV is exactly the possibilty of refueling at a station.

This is exactly why I think Hydrogen cannot win. The infrastructure is very costly to buy and disruptive to install.

BEV charging is already in place at many houses. Supercharger stations are relatively inexpensive to build.

 

[strider]

PV-generated electricity -> hydrogen -> fuel cell -> electricity -> electric motor

vs

PV-generated electricity -> battery -> electric motor

Which is simpler? Why bother with the added complexity especially in your own garage and your own solar? The only theoretic merit of FCV is exactly the possibilty of refueling at a station.

+1. I assume you're proposing to crack water to get the hydrogen. That takes an INSANE amount of energy. Why would you waste all the energy to crack water when you could be using that energy to drive or run your oven or whatever?

Also, cheap hydrogen from nat gas will run out at some point. It's a finite resource. A BEV allows you to drive on electricity from any source, be it nat gas, nuclear, solar, wind, geothermal, whatever. So why not have the most flexible transportation system possible?

 

[widodh]

+1. I assume you're proposing to crack water to get the hydrogen. That takes an INSANE amount of energy. Why would you waste all the energy to crack water when you could be using that energy to drive or run your oven or whatever?

Also, cheap hydrogen from nat gas will run out at some point. It's a finite resource. A BEV allows you to drive on electricity from any source, be it nat gas, nuclear, solar, wind, geothermal, whatever. So why not have the most flexible transportation system possible?

You forget one major thing here. With a BEV you as the end-user get the freedom to use any power source. As long as it's electrical energy you can charge your car and drive.

Hydrogen is something you will have to buy from somebody. That's a whole chain of companies and governments who can control it, make a profit and tax it. So you are depending on them again instead of getting freedom.

They just want to "replace" petrol or diesel with something else they can control. They don't want you to have control. It's all about the money. Capitalism first, environment second.

 

[stopcrazypp]

Okay, as you insist on looking at the efficiency more closely, let's look at the chain from well to wheel.

Not sure where you pulled those numbers, but here's what Argonne National Labs' GREET Model (used widely by the US Department of Energy) says for well to wheel (numbers are in Btu/mi).

Hydrogen Fuel Cell vehicles:
Distributed NG SMR: 3937
Distributed Electrolysis: U.S. Mix: 7506
Distributed Electrolysis: CA Mix: 6282
Central NG SMR: 3875
Central Biomass: 4615
(NG SMR = Natural Gas Steam Methane Reformation)

EVs:
U.S. Mix: 3136
CA Mix: 2636
Coal: 4282
NGCC: 3065
Biomass: 7268
(NGCC = Natural Gas Combined Cycle)
http://greet.es.anl.gov/results

As you can see, the only pathway where hydrogen is more efficient is biomass. Unfortunately, the ANL does not have a line for conventional natural gas generation, but it does have NGCC. You can kind of work out average natural gas by using Coal = 32.5%, NG = 42.4% (2012 numbers from EIA) and you get 3282 Btu/mi for average natural gas, still significantly lower than hydrogen from natural gas.

This result is kind of surprising to me too. Previously I did comparisons of hydrogen vs EV and in the natural gas pathway hydrogen is slightly better. But I use the more optimistic assumptions provided by the hydrogen side and the real world efficiency numbers for the EV side. I guess ANL is using less optimistic numbers for hydrogen.

 

[Yggdrasill]

He's also still taking the 65% efficient FCV figure from Toyota as if it's accurate in the real world, but not using the most efficient NG generating plant numbers. I'd bet Toyota is using their best number, not average.

A hydrogen fuel cell runs at constant load pretty much always. The (typically NiMH) hybrid-battery absorbs any excess power production and provides extra oomph when needed. That means peak efficiency will be pretty close to real life efficiency.

Using 60% generating efficiency and a 90% charging efficiency, (my car charges between 92-94% efficiency now), gives us a 43.8% efficiency today.

You're probably charging at 220V with cooler ambient temperatures. I assumed a more average efficiency, with a significant percentage charging with 110V and using A/C to keep the battery cool.

- - - Updated - - -

Natural gas distribution to steam reformation plant: 96.5%
Hydrogen production: 70% efficiency
Fuel cell power station with cogeneration: 85%
Power grid distribution: 93.5%
Charger efficiency: 85%
EV efficiency: 90%

Total efficiency: 41%

If you have a fuel cell power plant that is stationary, you can run a turbine using the waste heat to generate electricity, which can bring your efficiency up as high as 85%. I wasn't able to find real world numbers for the efficiency, but if you assume all of your numbers are accurate, you need just over 72% efficiency at the fuel cell power plant for the EV to be more efficient overall.

This is possible, but it assumes fuel cell use in power stations becomes financially viable, something that hasn't happened yet. Maybe at some point in the future all the NG power plants will be using fuel cells, but in that future, I also posited that the efficiency of the FCV wiuld have risen to 42.7%.

- - - Updated - - -

Why would you use a 42.45% efficiency number for natural gas powerplants?

If you are comparing against a theoretical hydrogen production system that doesn't exist you should at least compare with the best natural gas combined cycle powerplants that exist now.
Instead of building hydrogen boondoggle plants, we could just build more efficient natural gas powerplants.
This is already happening as new 60% efficient plants are built:
GE Secures $1.2bn in New Orders for Environmental Leader
Irsching Power Station - Wikipedia, the free encyclopedia

Over a 10 year period from 2001 to 2010 California has improved its natural gas generation efficiency by 31% by replacing old plants with new ones.
That will continue and hydrogen will never catch up to that.

Plus in the future natural gas will allow us to improve the 93.5% efficiency cited for the distribution system by making more smaller plants closer to the consumers of the electricity.

The average US NG power plant in 2012 had 42.45% efficiency. I used 55% effficiency for the future scenario, which assumes 60% efficient NG power plants in real life conditions. (Median NG power plant age is around 20 years, and aging affects efficiency. Many NG power plants are frequently started up/shut down or run at a suboptimal load to follow demand.)

- - - Updated - - -

Not sure where you pulled those numbers, but here's what Argonne National Labs' GREET Model (used widely by the US Department of Energy) says for well to wheel (numbers are in Btu/mi).

Hydrogen Fuel Cell vehicles:
Distributed NG SMR: 3937
Distributed Electrolysis: U.S. Mix: 7506
Distributed Electrolysis: CA Mix: 6282
Central NG SMR: 3875
Central Biomass: 4615
(NG SMR = Natural Gas Steam Methane Reformation)

EVs:
U.S. Mix: 3136
CA Mix: 2636
Coal: 4282
NGCC: 3065
Biomass: 7268
(NGCC = Natural Gas Combined Cycle)
http://greet.es.anl.gov/results

As you can see, the only pathway where hydrogen is more efficient is biomass. Unfortunately, the ANL does not have a line for conventional natural gas generation, but it does have NGCC. You can kind of work out average natural gas by using Coal = 32.5%, NG = 42.4% (2012 numbers from EIA) and you get 3282 Btu/mi for average natural gas, still significantly lower than hydrogen from natural gas.

This result is kind of surprising to me too. Previously I did comparisons of hydrogen vs EV and in the natural gas pathway hydrogen is slightly better. But I use the more optimistic assumptions provided by the hydrogen side and the real world efficiency numbers for the EV side. I guess ANL is using less optimistic numbers for hydrogen.

Your numbers say nothing about efficiency. How can we know that the assumed vehicle energy requrements are the same for FCV and EV? Often you see that research institutions assume that EVs are small city cars while hydrogen FCVs are full-sized family cars. A larger vehicle will naturally use more energy per mile.

 

[JRP3]

I'd say that's a rather wild assumption on your part. More likely the people who obviously put a lot of time into researching these numbers know enough to use similar vehicles for comparison.

 

[evme]

The energy required to compress 1 kg of hydrogen from 1 bar to 700 bar is 2.37 kWh. With a 60% efficient compressor, that means that the required energy is about 3.95 kWh. 1 kg of hydrogen contains about 40 kWh, so that works out fairly accurately to 90% efficiency.

What about the hydrogen content loss during compression? And that 3.95 kWh to run the compressor is generated from an NG powerplant that is 42.45% efficient?

10-30 years into the future. (Coming with an accurate number is impossible. It's easier to say what will happen than to say when.) As I mentioned earlier 60% is under ideal conditions. Real life does not equal ideal. Plus there will of course be older plants still in operation.

In 30 years, all the current NG powerplants would already be swapped to newer 60% efficient ones. In 30 years, the 60% powerplants will be the oldest powereplants and the newer ones will be even more efficient. This is assuming that we still use NG by then and have not swapped to something better by then. This is why it is important to consider the time scale.

 

[Yggdrasill]

I'd say that's a rather wild assumption on your part. More likely the people who obviously put a lot of time into researching these numbers know enough to use similar vehicles for comparison.

That would have been great. But in my experience, many experts often use ridiculous assumptions which have no basis in reality. You need to know their assumptions to have any way of assessing the validity of their conclusions. And I couldn't find their assumptions on the linked site.

 

[Yggdrasill]

What about the hydrogen content loss during compression?

There's no loss. 1 kg before compression is still 1 kg after compression.

And that 3.95 kWh to run the compressor is generated from an NG powerplant that is 42.45% efficient?

I can live with that assumption. Okay, so you need 9.3 kWh of natural gas for the compression.

That means that if at the end of the compression you have 1 kg of Hydrogen or 40 kWh, you would need to have inputed 50/0.7 + 9.3 = 66.4 kWh of natural gas. The total efficiency for hydrogen production + compression would be 40/66.4 = 60%. And the efficiency for the compression would be 86%, as 0.86 * 0.7 = 0.60. The corrected numbers would be:

Electric car, current situation:

Natural gas distribution to power plant: 96.5%
Power plant efficiency: 42.45%
Power grid distribution: 93.5%
Charger efficiency: 85%
EV efficiency: 90%

Total efficiency: 29.3%

FCV, current situation:

Natural gas distribution to steam reformation plant: 96.5%
Hydrogen production: 70% efficiency
Hydrogen compression: 86% efficiency
Hydrogen distribution: 90% efficiency
Hydrogen fueling: 98% efficiency
FCV efficiency: 65%

Total efficiency: 33.3%

And assuming the power for the compressor came from a 55% efficient power plant, the numbers would be:

Electric car, some time in the future:

Natural gas distribution to power plant: 97%
Power plant efficiency: 55%
Power grid distribution: 94%
Charger efficiency: 90%
EV efficiency: 90%

Total efficiency: 40.6%

FCV, some time in the future:

Natural gas distribution to steam reformation plant: 97%
Hydrogen production: 75% efficiency
Hydrogen compression: 88% efficiency
Hydrogen distribution: 95% efficiency
Hydrogen fueling: 98% efficiency
FCV efficiency: 70%

Total efficiency: 41.7%

Now, was it really important to do those calculations? I would say no, the conclusion is unchanged.

In 30 years, all the current NG powerplants would already be swapped to newer 60% efficient ones. In 30 years, the 60% powerplants will be the oldest powereplants and the newer ones will be even more efficient. This is assuming that we still use NG by then and have not swapped to something better by then. This is why it is important to consider the time scale.

The US has over 100 GW of natural gas power plants that are older than 30 years. This is about 25% of all natural gas power output. Thus it seems unlikely that all the generating capacity now less than 30 years old will be retired in 30 years.

Also, as I mentioned, the 60% efficiency number is at ideal conditions. Power plants rarely operate in ideal conditions.

 

[Reykjavik]

This is possible, but it assumes fuel cell use in power stations becomes financially viable, something that hasn't happened yet. Maybe at some point in the future all the NG power plants will be using fuel cells, but in that future, I also posited that the efficiency of the FCV wiuld have risen to 42.7%.

Yet you are happy to assume that Fuel cells will be economically viable if you have the additional costs of packing it down into a car, and designing it to pass crash tests.

According to the numbers you presented, if you can gain 7 points of efficiency (an increase by a mere factor of 1.11) by centralizing your fuel cell power production, you improve your efficiency overall by switching to electric grid distribution. If you want to talk about costs, you will lose there too. Go find the cost per mile for hydrogen fuel, compare it to the cost per mile of a battery electric vehicle. Then compare the costs of the actual vehicles.

 

[Yggdrasill]

Yet you are happy to assume that Fuel cells will be economically viable if you have the additional costs of packing it down into a car, and designing it to pass crash tests.

No. I do not. Fuel cells are a dead end. I am merely saying that using natural gas in a FCV would be more efficient than using natural gas in an EV.

EVs will prevail because they use every other fuel more efficiently than a FCV, they are convenient in that you never need to visit a fueling station and they and the associated infrastructure is cheaper to manufacture.

According to the numbers you presented, if you can gain 7 points of efficiency (an increase by a mere factor of 1.11) by centralizing your fuel cell power production, you improve your efficiency overall by switching to electric grid distribution.

As your own calculations showed, the EV still failed to beat the FCV in your hypothetical future.

 

[Reykjavik]

As your own calculations showed, the EV still failed to beat the FCV in your hypothetical future.

I didn't do a calculation for the future. I did a calculation using your numbers for the present. If you look at the future numbers, the electrical distribution and motor combined are 92.9% as efficient as the distribution alone of hydrogen. If you start with hydrogen, a stationary fuel cell power plant has to be 1.07 times as efficient as the one in the car to be as efficient overall, assume the "future" numbers, 1.11 times as efficient if you assume the "present" numbers.

Not to mention that your numbers are wildly skewed in favor of hydrogen. According to http://en.wikipedia.org/wiki/Fuel_cell#In_practice, fuel cell vehicles are closer to 36% efficiency in real world conditions.

If you start with hydrogen, the best thing you can do is put it straight into a highly efficient stationary fuel cell and transmitting the power through the grid to a BEV. That is how good BEVs are, they let you run any power source more efficiently and more flexibly than by using it to directly fuel the car.