Alstom Fuel Cell Train

[Theakerr]

It will be most interesting to see how this concept sells, but it does look rather neat

http://www.alstom.com/press-centre/2016/9/alstom-unveils-its-zero-emission-train-coradia-ilint-at-innotrans/

[4630]

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[jjb1970]

Fuel cells are one of those technologies that have been the coming thing for decades. Fuel cell technology is mature and proven, the problems are the cost, life of fuel cell stacks and the fact that their green credentials rather depend on the fuel source.

[Dagworth]

Fuel cells are one of those technologies that have been the coming thing for decades. Fuel cell technology is mature and proven, the problems are the cost, life of fuel cell stacks and the fact that their green credentials rather depend on the fuel source.

The fuel source is far from environmentally friendly.

 

https://en.wikipedia.org/wiki/Hydrogen_production

[jjb1970]

The fuel source is far from environmentally friendly.

 

https://en.wikipedia.org/wiki/Hydrogen_production

I worked on one project that was proposing to use wind turbines to produce hydrogen by electrolysis of seawater. Ordinarily that is a very inefficient, energy intensive technique but with wind energy and no grid to distribute the electricity from normal wind turbine generators it was quite a neat idea I thought. That said, most fuel cell projects I worked on were high temperature cells using either natural gas or methanol fuel and were not particularly green.

[Edwin_m]

There's a longer article in October's Modern Railways.  This confirms that at least one of the sponsoring authorities has surplus wind power that they can use to generate hydrogen with effectively zero emissions. However it also points out that other parts of Germany are still burning lignite and there would probably be more environmental benefit if the "spare" power replaced that instead. 

[Reorte]

There's a longer article in October's Modern Railways.  This confirms that at least one of the sponsoring authorities has surplus wind power that they can use to generate hydrogen with effectively zero emissions. However it also points out that other parts of Germany are still burning lignite and there would probably be more environmental benefit if the "spare" power replaced that instead. 

If the spare power lines up neatly enough with demand (or the demand can be shifted, which often it can't), which is rather an issue with wind power. At least hydrogen production with spare power is (more) of a "doesn't really matter what time it's done" process, effectively storing excess power for later use.

[Ian Smeeton]

Isn't it normally called a battery?

 

Regards

 

Ian

[jjb1970]

Isn't it normally called a battery?

 

Regards

 

Ian

No, a fuel cell is not a battery, it is a technology in which a supply of hydrogen and oxygen induces a chemical reaction to produce electricity.

[62613]

No, a fuel cell is not a battery, it is a technology in which a supply of hydrogen and oxygen induces a chemical reaction to produce electricity.

A sort of 'Reverse electrolysis', then? How efficient are fuel cells over their whole life?

[jjb1970]

A sort of 'Reverse electrolysis', then? How efficient are fuel cells over their whole life?

There is no simple answer to that one as it all depends on the particular technology (fuel cells are a group of technologies), the system integration (is there any heat recovery if it is a high temperature fuel cell technology?) and the fuel supply arrangements (are they using compressed hydrogen or reforming from a feed stock such as natural gas or methanol?). A typical fuel cell efficiency in isolation is not dissimilar to a diesel engine, as with a diesel engine the efficiency goes right up if waste heat is recovered (although I'm guessing Alstom are using a low temperature PEM type technology) and if there is no need for fuel reforming then that reduces the parasitic power demand and so increases efficiency. In a sense it is a bit like the proverbial length of string.

What is perhaps more relevant is the life of the fuel cell stacks but that is not an efficiency issue. Some of them can be quite short lived and they're very expensive. They can also be degraded by maloperation, reverse power to the stacks can kill them.