Speak EV - Electric Car Forums banner

1 - 7 of 7 Posts

·
Registered
Joined
·
701 Posts
I'm really not convinced by Hydrogen technology.

I'd like to see an energy analysis before anything else. As I read that it is a hydrogen storage mechanism.
I'd be a bit concerned about stability to 50C and 1g -> 1l - that reads to me explosive :)
 

·
Registered
Joined
·
3,837 Posts
There are so many applications of differing technologies where final unit cost can be ignored, and so many where it cannot. It may be that a pellet driven drone can be justified at a high cost, but I am more interested in the cost per mile of a car, and the associated environmental costs.
 

·
Registered
Joined
·
3,066 Posts
I was reading earlier that JDM i-miev's could be ordered with an SCiB battery pack - effectively giving greatly increased range (I think 1.7 times was mentioned, compared to li-ion). I wonder why we haven't seen it adopted over here?
 

·
Registered
Joined
·
7,948 Posts
This has been knocking around for quite a while now but it is still relavent IMO...

hydrogen-vs-electric-flow-diagram.jpg


It is from a paper by Ulf Bossel from 2006...

http://www.industrializedcyclist.com/ulf bossel.pdf


What it shows is that it is not efficient to use hydrogen.

However, I suggest that efficiency is not the most important factor when considering hydrogen. It is important right now and will remain so for the foreseeable future because we have no way to create hydrogen that does not use fossil fuels... well, not in any quantity. Once we find a way to create it on a commercial scale using renewables then efficiency becomes less important. If the energy to create it is free then it becomes cheaper than even the most efficient power station run on gas or nuclear.
 

·
Registered
Joined
·
5,596 Posts
Discussion Starter #6
...............we have no way to create hydrogen that does not use fossil fuels... well, not in any quantity. Once we find a way to create it on a commercial scale using renewables then efficiency becomes less important. If the energy to create it is free then it becomes cheaper than even the most efficient power station run on gas or nuclear.
The report at the start of this thread ( Drone flight powered by lightweight hydrogen-producing pellets ) indicates that hydrogen was manufactured on demand using pellets made from proprietary chemicals. They are said to be stable to 50C and need a small amount of heat to activate them.

The big issue is whether this system is scalable to produce sufficient hydrogen to run a motor large enough to run a car at adequate performance. On a small scale it is capable of replacing existing battery technology for a small aeroplane. As such, the indication is that scaled up it would be lighter than existing vehicle power systems with like for like power output.

Dispensing with the need for a heavy pressurised tank is attractive. And on the face of it, re-fueling by adding pellets would seem to be a rapid process. Of course that report leaves many questions to be addressed such as just how stable are the pellets, and what residue is left to be disposed of after use. But surely the potential here is worth investigating on a larger scale.
 

·
Registered
Joined
·
7,948 Posts
The question I would ask is how and from what are the pellets made?

If, as I suspect, they are made using a process that uses a lot of fossil fuels then we are no further forward. Without knowing the answer to that and many other questions we might have if is just another hope in the hydrogen story :)
 
1 - 7 of 7 Posts
Top