OT: need some help with fuel cells

[Technomage-hawke]

On Thursday 24 April 2008, koder wrote:

>
> Recreational vehicles and yachts use solar panels to power some decently
> sized storage batteries. If you put up enough of them you can run a
> computer system.
batteries are all fine and good, but require frequent replacement (every 1-2 
years down here in the desert), and have hazardous materials in large 
quantities.

>
> Unfortunately the cost of solar is escalating. My original system cost
> under a thousand dollars. Today it would probably be twice that.
yep. that makes it harder for those on a fixed income to get anything 
worthwhile out of such systems as well (cost higher than cash available).I am 
sure I could build a full sized panel over time (by adding smaller modules to 
it).

>
> Of course when I build the next one I will ask it to do more with the
> additional expense.
>
> My wish list consists of more panels, bigger batteries, and a wind
> powered generator for cloudy days.
same here, except I would like to build all my stuff from easily available 
materials. call it a poor man's energy policy. :)

>
> There are a number of sites in the net dealing with the topic of solar
> direct to batteries. They are far from complete. You will have to
> supplement with written material.
I'm already getting that and worse. a lot of the diagrams online for any fuel 
cell are of the simple overlay type that are meaningless to those of us who 
want to build such a unit. so far, I have found NO technical diagrams or even 
any materials lists for something as simple as a PEM fuel cell. Now I have 
found plenty of places that sell individual parts for such (such as the 
backing plates, the PEM material itself and the field flow plates).

>
> This is some different from the fuel cell systems you asked about, but
> the fuel cells are using battery and solar and adding in the
> inefficiency of the hydrogen. The hydrogen is great for energy
> containment and transportation such as powering your car, but the
> equipment is a bit pricey.
actually, from my reading, hydrogen is very efficient (unless you "burn" it in 
a system similar to internal combustion engines, then you are stuck with the 
waste heat, mechanical losses, etc). Direct conversion to electricity is 5-6X 
more efficient at a minimum (unless you are having to convert carbon heavy 
fuels using a reformer, then it drops below 50%). 

>
> Cost will be directly related to how much electric you intend to use and
> store. You can start with part of it and expand as budget, knowledge and
> goals expand.
well, from what I have been able to determine, one can get (from a properly 
designed fuel cell) approximately 3 watts/cm^2 of fuel cell surface area. 
that means that you don't need something monstrous to power a house. a fuel 
cell stack made up of plates 10x10 cm 10 cm deep will give you roughly 3 KW 
of usable energy. This is not theoretical, its the same type of units they 
use on the space shuttle. 

>
> If you want to go further let me know. There are several people in the
> area working on this.

I definitely do. hey, if it means getting a paying job to do this as well, I'm 
all in!