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E-M:/ Hydrogen is the future ...



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Enviro-Mich message from "Lowell Prag" <lprag@mail.msen.com>
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Was: Re: E-M:/ Where to find alternative fuel stations in Michigan ...

Rane Curl said:

... see below ...

Hello Rane,

I don't agree with your argument against the economics of hydrogen for use
in fuel cells to create electricity, as you have left out some key
factors.

First though, you are correct in pointing out that strictly speaking,
hydrogen is not a fuel but rather, an energy carrier, in the same sense
that electricity is not a fuel but rather, an energy carrier.

Also, it is important to note that there is no free lunch with hydrogen,
as it takes as much energy to extract hydrogen from water, as you end up
with.

With those points in mind, let me briefly address two issues, while also
keeping in mind that hydrogen is the perfect "fuel", as it is completely
renewable and also completely non-polluting, as the only two by products
when used in a fuel cell to create electricity, are pure water from which
you can get more hydrogen, and heat which can also be captured and reused.

The economics of hydrogen extraction:
-------------------------------------

If one uses solar photovoltaic electrolysis for the extraction of hydrogen
from water, the energy cost of the process is zero, as the Sun's energy is
free and with the advancements in solar photovoltaic concentrators using
lenses to amplify the sunlight, the efficiency of extraction rises upwards
to over 100 times that of standard photovoltaic electrolysis.

i.e. if one has a photovoltaic cell rated at x watts with 1 Sun and you
amplify that to 100 Suns with a solar concentrator, you will then get
(x watts) times (100) = 100x watts from that pv cell.

These types of pv cells are called multijunction and they can not only
take the heat produced in such a process but also, are inherently much
more efficient than standard pv cells, as they utilize the energy within
the full spectrum of sunlight.

Spectrolab, http://www.spectrolab.com/ and others have perfected these
multijunction pv cells and they are now off the shelf items.

In short, the energy from the sunlight falling on the USA, far exceeds the
btu content of all of our fossil fuel consumption and it is a relatively
simple matter to use that free energy for the production of hydrogen.

The economics of hydrogen distribution:
---------------------------------------

The major advantage of hydrogen as an energy carrier, is that there is no
lose of energy in distribution. Whereas with electricity as an energy
carrier, one can only distribute it for relatively short distances, due to
the resistance in the transmission wires.

For all of the nay sayers, I can only say wait and see.

Within 25 years, we will create giant photovoltaic Sun farms in the USA,
for the production of hydrogen, and we will build the infrastructure to
distribute the hydrogen nationwide, for use not only in fuel cell powered
cars and trucks but also, fuel cell powered homes and factories, to create
electricity directly at the point of use.

Regards,

Lowell Prag

Rane Curl said:

> -------------------------------------------------------------------------
> Enviro-Mich message from Rane Curl <ranecurl@engin.umich.edu>
> -------------------------------------------------------------------------
>
> On Thu, 29 Jun 2006, Lowell Prag wrote:
>
> ...snip...
>> In the long term, only a hydrogen based fuel economy will solve those
>> problems, as hydrogen can easily be obtained from water, not fossil
>> fuels
>> or other hydrocarbons, and the only by product of using hydrogen in fuel
>> cells, is pure water and heat.
>>
>> Two problems with hydrogen though, producing it from water in a manner
>> that does not also produce CO2, and over coming the oil lobby in
>> Washington, in order to build a nationwide hydrogen delivery
>> infrastructure.
>
> "The term 'H2 economy' is a misnomer. Our present economy is based on
> fossil fuels with a small contribution from nuclear energy. H2 is an
> inefficient energy carrier, not an energy source. For the next foreseeable
> 20-30 years, we will still depend on fossil fuels, so what use would H2
> achieve? Conversion of fossil fuels to H2 inherently involves a large
> irreversible energy loss. The best lower heating value (LHV) efficiency of
> a H2 plant from natural gas is 65%, and of a coal plant is 55%. There is
> no available energy conversion device based on H2 that has a sufficiently
> large advantage to compensate for this loss, and conversion of nuclear or
> solar electricity to H2 makes no sense. The electricity alone to produce
> one million BTU would be about $50, while its market value as hydrogen
> would be only $16."
>
> from "Demystifying the Hydrogen Myth" by Prof. Reuel Shinnar (2004).
> http://csauth.ccny.cuny.edu/ci/cleanfuels/upload/Hydrogen-Myth.pdf
>
> As I have pointed out before, the current fuel crisis is because the world
> is running out of oil ("peak oil"), but the world ran out of hydrogen
> billenia ago. It would have to be manufactured, and that is inefficient
> compared to using the electricity necessary for electrolysis directly. All
> hydrogen can be is a less efficient way than electricity to distribute
> energy from a nuclear or solar generating station.
>
> Prof. Shinnar does not address the best option for a future transportation
> fuel, which would be cellulosic alcohol(s) (currently being discussed
> primarily in terms of ethanol, but not restricted to that). This is an
> alternate way of capturing solar energy, but only useful if it is self
> supporting - the efficiency being made high enough so that no fossil fuel
> is necessary in its cultivation and processing. No adequate research
> program for accomplishing this is yet on the table.
>
> --Rane L Curl
>
>
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