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BEST-L  September 2005

BEST-L September 2005

Subject:

Re: FW: ASES Meeting - "Hydrogen Production using Solar Energy"

From:

John Hurford <[log in to unmask]>

Reply-To:

[log in to unmask]

Date:

Tue, 20 Sep 2005 16:04:22 -0400

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (116 lines)

The big issue in all of these alternative energy sources is one of true 
energy cost; not just dollars.

 In other words, if you spend a megawatt of power to produce a device that 
can only yield 0.75 megawatts over its lifetime, then the process is 
inefficient. This has been the case with solar photovoltaic panels (this 
according to the late Dr. Howard T Odum of UF's College of Environmental 
Engineering and Sciences). This is also the case with batteries. It is their 
portability that gives them value, not energy efficiency.

 That is not to say that solar photovoltaic panels have no value. When used 
with rechargeable batteries, they are excellent for remote lighting needs 
where providing permanent AC power would be prohibitive, such as blinking 
stop lights on remote rural roads. They are great for many low-power items 
like calculators and clocks. But, thinking that this energy source can 
produce the quantity of electrical power used in this county is na´ve. 

 As an exercise, calculate the number of panels necessary to produce 1100 
megawatts per hour of 240 Volt, 300 Amp service. Eleven hundred megawatts is 
the power rating of just one of the nuclear units at the Crystal River Power 
Station.

 As to hydrogen as a fuel produced from other energy sources, the 
thermodynamic efficiencies quickly indicate the negative energy result. If 
we assume a 50% efficiency for each power conversion ( a generously liberal 
value), we can see that as a primary fuel, Hydrogen is not the way to go. 
Like solar panels; however, hydrogen fuel will have a niche where it's other 
values out way the negative energy condition.

 To illustrate the point, compare the thermodynamic efficiency for producing 
one unit of output power from a hydrogen system and one unit of output power 
from a diesel fuel system. Both system are primarily fueled by diesel oil.

 HYDROGEN SYSTEM: 
 
Fuel 1 Power station 2 Hydrogen generation 3 

 Hydrogen conversion 4 Output

 Four conversion steps at 50% efficiency require 16 units of input power for 
one unit of output power. 
 
DIESEL:
 
Fuel 1 Power station 2 Output

 Two conversion steps at 50% efficiency require four units of input power 
for one unit of output power. 
 
Therefore, for the same amount of useful output power, the direct use of 
primary fuel yields the least consumption of the polluting energy source. 
"Clean" hydrogen actual produces four times the pollution as the "dirty" 
diesel engine.

 Bio-fuels are wrought with all of the same efficiency issues, and yield the 
same green house gases as any carbon based fuel.

 Producing "Green energy" from a waste stream, such as the Archer Southwest 
Landfill, does reduce the amount of fossil fuel a community would consume, 
however, the carbon dioxide issue still exists.

 Conservation and improved efficiencies are the best methods for reducing 
the quantity of fossil fuel.

 This is not the end-all with respect to this subject, but considering the 
issues raised, maybe the researches will consider the most rewarding paths 
to pursue.
 On 9/19/05, Marcelo Dias de Oliveira <[log in to unmask]> wrote: 
> 
> That must be a really nice presentation.
> It combines the use of the most promising renewable source - solar energy, 
> used for producing a fuel that might become very important in terms of 
> environment emissions. Unfortunately I don't have at the top of my head some 
> technical information to emphasize the importance of this approach, what of 
> course will be given during the presentation. But I for sure recommend 
> everyone interested in renewable sources and sustainable fuel production to 
> attend this presentation.
> That is, if my recommendation is worth any attention.
> 
> Regards,
> 
> Marcelo.
> ----- Original Message -----
> From: Brian Becker<mailto:[log in to unmask]>
> To: [log in to unmask]<mailto:[log in to unmask]>
> Sent: Monday, September 19, 2005 5:42 PM
> Subject: FW: ASES Meeting - "Hydrogen Production using Solar Energy"
> 
> 
> -----Original Message-----
> From: American Solar Energy Society at UF [mailto:[log in to unmask]] On
> Behalf Of [log in to unmask]<mailto:[log in to unmask]>
> Sent: Monday, September 19, 2005 4:35 PM
> To: [log in to unmask]<mailto:[log in to unmask]>
> Subject: ASES Meeting - "Hydrogen Production using Solar Energy"
> 
> Dear Members,
> 
> ASES will be holding its first meeting of Fall 2005 tomorrow (Tuesday) at
> the Reitz Union. The highlight of the meeting will be a talk by Dr. Ingley
> on "Hydrogen Production using Solar Energy".
> 
> Date : Tuesday, September 20, 2005
> Time : 6:00 PM
> Place : Reitz Union, #282
> Talk : "Hydrogen Production using Solar Energy" by Dr. Ingley
> 
> 
> We will also discuss about the upcoming Gainesville Solar Home Tour which
> is scheduled for October 2, 2005. For more information about the Tour,
> please visit www.mae.ufl.edu/ases <http://www.mae.ufl.edu/ases><
> http://www.mae.ufl.edu/ases>
> 
> If you have any questions, please contact us at [log in to unmask]<mailto:
> [log in to unmask]>
>

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