alt.energy.homepower

dances_with_barkadas@ wrote:
>> the rather inconvenient temperature that liquid
>> hydrogen requires, it's propensity to leak through near everything,
>> the way it changes materials, it's cost, flammability or explosive
>> nature.
>
> As the reference indicated, I'm talking about gasous Hydrogen. They
> sell the cylinders in the Yellow Pages, it can't be rocket science.
> Liquid H2 is rocket science.

You're suggesting storing heat in hydrogen gas as better than
storing it in liquid water? Hydrogen gas is pretty light. It
seems to me that it'll take a heck of a lot of very light gas
to equal the heat capacity of a few gallons of water.

Why not put some numbers to it? Say you're looking to store
heat for keeping the house warm, around 77F, 25C, 298K.

/
at 25C specific heat is kJ/kgK and density kg/m^3.
This gives us heat storage of 4169 kJ/m^3K.

/
/
at 298K specific heat is kJ/kgK and density is kg/m^3.
Roughly speaking (since I don't want to bother with ideal gas laws
and whatever pressure those S-Mart hydrogen tanks use) this gives
us heat storage of kJ/m^3K.

Which would you rather use? Very cheap water at 4169 kJ/m^3K or very
expensive hydrogen at kJ/m^3K? Let me tell you a secret, one of
them stores 3200 times more than the other. :)

Anthony