Hi, Guys,

I've been involved with some of this and it's absolutely essential that you absorb the momentum and apply it against the starting inertia. Use batteries for moving down the highway. Starting and stopping will kill you.

Think of it as a 3-phase process: 'Starting' costs are canceled by 'Stopping' assets. 'Running' is separate account.

Good luck!

Hydrogen is very expensive to use in terms of CO2 production at the source. Hydrogen is expensive to store and to transport. There are other technologies that do not release even water and are expensive too, but they can provide more miles. The pretense that there is only water in the exhaust is over worked. Any electricity used to produce hydrogen is much more efficiently used in battery vehicles. ZEBRA Batteries are available for long bus runs at much lower cost than hydrogen fuel cells and storage equipment. NGK make sodium sulphur cells that can be adapted to busses as well. Very clean burning of diesel even can be done with Capstone turbines. Every live body in the world breathes out CO2, so there is no reason why buses can not. A version of the Capstone turbine puts out cleaner air on California's busy roads than it takes in except for a little more CO2 and water added.

A diesel engine with a large flywheel and Artemis pumps and motors will get much higher efficiency, well to wheel, and cost less. And yes there are good filters for the exhaust. Use bio-diesel to pretend that the fuel is carbon neutral. NGK makes fuel cells that can run on gases made from charcoal. Charcoal is more carbon neutral than bio-ethanol and clever gas producers can be made with long known techniques. ..HG..

Um nope. As a fuel cell bus using h2 from nat gas uses less nat gas then either a nat gas powered bus or a bev bus with power from a nat gas powered powerplant it makes for less co2 per mile.

And the fuel cells are getting better every generation.

@wintermane,
I've seen a couple of people claim that you can use less natural gas for H2 production/use than using the natural gas itself.

I am not saying this is not true, but I find it very hard to believe and would love to see some scientific, INDEPENDENTLY VERIFIED, numbers to back this up. Do you have any pointers?

As I said, I'm not saying it's impossible because I might be missing something. But on a simple common sense test It seems unlikely that we could derive H2 from natural gas and somehow get more energy out of the resulting H2. Is this because of the "higher efficiency" of the fuel cell compared with burning the nat gas in an ICE engine?

If so, is this with real world fuel cells rather than theoretical maximums the fuel cell COULD reach?

Does it take into account that you only get 70% efficiency of the energy when you reform the nat gas to get H2? Does it take into account the compression, storage and transport of the H2 and the losses of H2 as it goes through all these stages (we all know that H2 is the tiny and it is notoriously bad about "leaking/bleeding off" and losing a lot of the H2 while it's just sitting around waiting to be used).

Like I said, I'm willing to be educated, but I want to see some actual data from an independent party that shows true "well to wheels" numbers.

Try toyota and friends they came up with the numbers have been known for a long time too.

Remember alot of the boring tech behind h2 has improved greatly over the years. Also lot of the "facts" people have are totaly bull. For instance alot of people talk bout the cost of compression but it only costs 2% more well to tank to use 10k psi h2 then 5k psi h2. A fact even I was surprised by.

Hydrogen only beats BEV if you use <40% efficient natural gas power plants. Plants are being built today at 60% efficiency so BEV's win.

WRT HFCV V NGV an ICE can reach 30-40% which is comparable to a fuel cell (~50%) using hydrogen from steam reformed natural gas (~60%)

Fuel cells running on natural gas for distributed CHP is a good idea. Hydrogen fuel cells for automotive use are not such a good idea.

Well remember the steam reformer is 70% eff now and will be better in the future. They have 75% versions.

As for the fuel cell they span from 40% to 60% and they expect to get 75% before 2015.

As for bev... remember we are talking long range large trucks. Thats one HEAVY battery and that alone hits eff quite a bit. To make matters worse many larger trucks use non lithium ion batteries and they are far less eff then lith ion. Nimh batteries for instance are only 66% eff add in the rechargers losses and your losing nearly half the power.