Posted on 08/13/2004 6:57:00 PM PDT by TigerLikesRooster
The technology's only at 8% efficiency. It requires 10%.
Question: Why the missing 2%?
Answer: Haliburton.
These technologies are as overhyped as the incessant predictions of the demise of hydrocarbon energy is mistaken.
A more efficient solar cell would be fairly revolutionary in itself. As it stands right now, if you currently pay $.11 or more per kilowatt hour then solar is already cost competitive. That means that for most of us it's still cheaper and easier to rely on the electric company, but if they can bring the costs of the panels down and improve their efficiency enough solar power will become the cheapest way for most homeowners to get their electricity.
Is hydrogen a volatile medium? Think Hindenberg. Think Hindenberg exploding.
| 8 | “At sun radiation at 1 KW/m2 at 10% efficiency the 7m2 cell would provide 700W=1hp during daylight.” |
1. Your estimate of available solar energy is far too generous.
| SOURCE |
(%) |
(W/m2) |
|
|---|---|---|---|
| 1. | solar constant | -- | 1370W |
| 2. | atmospheric loss | 27 | 1000W |
| 3. | cloud loss | 21 | 790W |
| 4. | sun angle loss1 | 50 | 395W |
| 5. | night time loss2 | 50 | 198W |
| 6. | cell conversion loss | 90 | 20W |
| Source Notes: 1. Average for hour-angle, season and latitude (37º N). Increased atmospheric path length was not considered. 2. See link. Continental U.S. average sunshine is 4.8 kilowatt-hours/ square meter/day, or 200 watts/square meter. That value is nearly identical with total losses shown for items 1-5 above. |
|||
2. I realize the syntax used by the author was questionable, but since he spoke of "a seven-metre squared array", rather than "a seven square meter array", I feel pretty confident that the intended meaning was 49 square meters.
3. In testing the reasonableness of the author's energy claims, you can avoid any question or discussion about the automobile's horsepower (whether maximum rated horsepower or operating horsepower) simply by employing the following reasoning.
| gallons of gasoline saved per year (11,000 miles @ 30 per gallon) |
367 gallons |
| energy per gallon | 120E6 Joules |
| total energy savings per year | 44E9 Joules |
| energy savings per second (Watts) |
1,400 Watts |
| energy per second per square meter of fuel cell array | 28 Watts |
| solar energy available per sq meter (see above table) |
20 Watts |
In other words, Dr. Auty's claim that "a solar powered fuel cell array of 49 square meters that is 10% efficient, would produce enough energy to drive an automobile 11,000 miles", is fairly close to reality.
HOWEVER, WHAT IS NOT CLOSE TO REALITY is some of the related claims and fuel cell requirements.
First, according to the article, the conversion process relies on solar ultraviolet radiation, but since UV comprises less than 10% of the total solar radiation, how can he have a cell that is 10% efficient???
Second, there is no such thing as a low price glass that is highly transparent to UV radiation. Just how economic a process will this be when it requires acre upon acre of amorphous quartz (or something equally expensive)?
Third, based on my experience, I would be extremely surprised if they can make such an array cheaper than solar cells (which are not an economically viable source of energy) and those run in the neighborhood of $500 to $1000 per square meter.
If you got lucky and got an 8% interest only loan to pay the cost of capitalizing Dr. Auty's contraption, the fuel cost would not be the $1.80 to $3.00 per liter that Dr. Auty claimed, but rather it would be about $6.24 to $12.47 per liter. (The number of liters per year equals 44E9 J divided by 140E6 J per liter of H2. At a cost of $500 per square meter, capitalization cost for 49 square meters of fuel cell would be $24,500 and the annual interest would be $1,960.)
There is only one way that Dr. Auty's scheme can be made to be economically viable. If you can't lower your own costs, you've got no alternative but to cause your competitors prices to rise. And you do that through government interference with the free market place.
Raise the gas tax, raise the road use tax, and do it both at the state and federal levels. Restrict new drilling for oil. Institute ever more restrictive environmental controls. Don't allow new refineries to be built. Require the use of oxygenated fuels. Institute a carbon tax.
Oh, wait, we're already doing that! Welcome home Dr. Auty, your time has finally come.
--Boot Hill
Thanks for your informative discussion.:)
By the time this type of energy is perfected, someone will find a different way.
Yes and in order to start a business you have to spend allot of money up front... When the technology reaches higher effecincies you can you it to power the process of makin the cells... Its a ways off but dont dismiss it..
Can 50 million Frenchmen be wrong?
You're welcome, but there was an error in the forth paragraph from the bottom of my post that I correct below.
“If you got lucky and got an 8% interest only loan to pay the cost of capitalizing Dr. Auty's contraption, the fuel cost would not be the $1.80 to $3.00 per kilogram that Dr. Auty claimed, but rather it would be about $6.24 to $12.47 per kilogram. (The number of kilograms per year equals 44E9 J divided by 140E6 J per kilogram of H2. At a cost of $500 per square meter, capitalization cost for 49 square meters of fuel cell would be $24,500 and the annual interest would be $1,960.)”In addtion to what I posted in my earlier post, another pitfall to Dr. Auty's fuel cell idea is with the tank that would be necessary to carry the liquid hydrogen. In his example of using this hydrogen to power an automobile, a 12 gallon gasoline tank would weigh about 20 pounds, but a tank for LH would have to hold 45 gallons, to provide the same mileage capacity, and the empty weight of this LH tank would be close to 400 pounds and would be bigger than a 55 gallon drum! (Look at your own car and try to figure where you could hide a 55 gallon drum!)
--Boot Hill
Hydrogen will be carried in an absorptive material inside a tank. Neither high pressure nor cryogenic tanks will be needed.
bump
I addressed the issue of storage as a gas because the article only spoke of that means of storage.
Nevertheless, there is no weight or volume advantage to storing hydrogen in another material. No matter the material you use, you will either drastically increase weight, volume or (more likely) both.
For example (since you didn't identify any specific material), here is what happens when you use a metal hydride as a storage medium for hydrogen: The metal hydride storage will be 20 times heavier and nearly 3 times the volume than an equal energy-quantity of gasoline.
In the example using a 12 gallon gasoline tank, that means your fuel would now weigh more than 1,500 pounds! You'd be better off sticking with the high pressure tanks (gag)!
--Boot Hill
Actually there is a more efficient solar cell being developed utilising the photsynthesis model found in ... of all things spinach. It seems that our current crop of biochemists have discovered that the photosynthesis that occurs in the spinach leaf is the most efficient known.
I think you may have been mislead by an over-reaching "science" reporter. One of the least attractive aspects of the spinach powered bio-solar cells is their efficiency. Even theoretical efficiencies are an order of magnitude below the common silicon solar cell.
--Boot Hill
Quite possible - I have never been much of a science (in the /bio/chem field) buff although the "quip" i was referring to seemed quite intriguing.
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