Re: Wind-energy customers pay less than those buying fossil-fuel power
- From: pv+usenet@xxxxxxxxx (Paul Vader)
- Date: Wed, 26 Oct 2005 19:24:41 -0000
"JMA" <jmDOTa@xxxxxxx> writes:
>> So, the key dimensions are 630kw, in an 11,686.5 square meter array.
>
>Where did you get those 11,686.5 square meter?
>Only 54 W/m^2 maximum output? From SANYO?
>Look at the figures:
>Total length: 315 m
>Depth: 13.7 m
>The area is about 4,315.5 square meter, which means a
>maximum output of 146 W/m^2.
I was going by the height, 37.1 meters. Since the solar arc is tilted to
point at the sun, neither the height OR the depth actually work for our
purposes, do they? OK, I'm going to have to punt on this part of the
analysis - I don't think I can use the solar ark dimensions this way. Dang
irregular shapes.
I hang my head in shame. Looking at the per-cell figures (using the 18.5%
efficient HIT210 cells), it looks like your original array size isn't all
that far off. So I'll concede the point that you can get something close to
10kw on a 100 square meter array.
>Look at the annual power output: 530,000 kwh.
>How many hours of Sun ? Make it 200 Sunny days during
>8 hours a day. It makes 1,600 hours a Year.
>The average output must be: 530,000 / 1,600 = 331 kw
To keep things simple, let's just divide it out to get an hourly figure:
530,000/365/24 = 60.5 kwh / hour. This is a 630kw array. Your 10K array
will (assuming you do as well as Sanyo) generate a bit under 1kwh / hr. 9
cents worth of electricity per hour, or $788 worth per year. Hey, I wasn't
far off on the payback. At a do-it-yourself build cost of $45,000 and
assuming nothing ever breaks or needs to be replaced, that's 57 years to
pay it back.
So I have to ask - if all your other calculations are right, why go PV to
make your hydrogen? Why not do it right this minute from the grid? What
you're doing is equivalent to telling someone that they have to pay for all
the gas they will use over their entire lifetime the moment they pass their
first driving test.
>>>Your $2.46 figure for 1kg hydrogen could be 10 times out.
>>
>> I came up with that number based on energy content.
>
>Sorry, but there is no known value for energy.
>It depends on the type of energy.
Say what? Of course there's a mesaure of energy content. By the way, I
found some real-world numbers for hydrogen while I was looking around.
Uncompressed hydrogen costs about $0.71/kg. Liquid hydrogen costs about
$2.20/kg.
>Yes. Storing hydrogen is a big problem.
>A figure of 350 bar or 700 bar is very dangerous.
>Not because of the hydrogen. It could be helium instead.
>Helium at 350 bar is dangerous as well.
What's your point? Nobody is using helium as a transportation fuel. Just
to make my point toally clear - I've been using figures for liquid hydrogen
throughout, becuase I think the idea of millions of cars traveling the
country with 10 cubic feet of 800 bar hydrogen each is laughable.
>> Fuel By Volume By Mass
>> Hydrogen 2.6kwh/l 39kwh/kg
>> Gasoline 9.7kwh/l 12.2kwh/kg
>
>You also have a mistake above. The figure for hydrogen by volume at
>STP must be 2.6 wh/l, not 2.6 kwh/l (a commume mistake I believe).
I thought I was being clear that I was using liquid hydrogen throughout.
STP hydrogen is good for nothing other than a zeppelin - you would need
6000 cubic feet of storage in your car to hold enough to get gas car range.
Heck, if you had a gas bladder that big I think you *would* be a zeppelin.
Nah - it would only lift 190 kilograms.
>The storage of hydrogen and the re-fuel is a problem.
>Cannot play with hydrogen like people used to play with gasoline.
>People simply cannot play with hydrogen and so it must be
>respected very carefully. So it could become safe.
It will become safe because people will treat it like it's dangerous? Wha?
>OK. The hydrogen storage will be bigger and much heavy.
>But the engine will be much smaller.
Debatable. A traction motor isn't exactly tiny, and again, not a
significant factor affecting mileage.
>No gearbox needed, no differential needed.
Hybrids have no transmission either (and they have a smaller engine). The only
way you can do without a differential is if you're using wheel motors. I
*love* wheel motors, but there's a lot of tricky engineering to do to make
that work. Expect to see an axle and difs on most electric vehicles for a
long time - it's a lot simpler.
>Electrical motors directly on the wheels.
>It is not the same car at all.
I'm getting the impression you think I have a problem with electric
vehicles. I think electric vehicles are the real future. I expect that over
the next 20 years, hybrids will get larger and larger batteries, and
smaller and smaller gas engines, until finally we have battery tech that
facilitates rapid charging, and the gas engine just goes away.
>Bad for storage tank, good in many other aspects.
Throw out all this hydrogen crap, and get on the hybrid electric
bandwagon. That's the way out of this mess.
>Not liquified.
>Hydrogen cannot be liquified because it is to much expensive.
>Liquid hydrogen costs money every hour it is stored and
>hydrogen that boils off must be released. It will be lost if not used.
And gaseous storage is better? I don't think so!
>Like the old cars about 100 Years ago.
You seem to be of the impression that fuel cells are new. They're more than
150 years old. Older than the gasoline internal combustion engine!
>Nope. Unless people lies the actual fuel cells efficiency is of
>about 50% and has an economical potential up to 70% (as
>electrolysis clearly shows).
70% is simply not going to happen, and electrolysis has nothing to do with
it.
>You must understand that a fuel cell is an electrochemical device
>and all electrochemical devices are by far much more efficient then
>simple heat devices.
You keep saying that, and it keeps being wrong.
>Yes. Fuel Cells costs are exhorbitant and they don't last forever.
>Fuel Cells must be replaced, like batteries must be replaced.
Today's current fuel cells as seen in test vehicles cost a huge amount more
than a gas engine, and tend to die in well under 10,000 miles (most demo
vehicles have been lucky to go half that before needing to be 'upgraded').
>A gasoline motor costs about $5,000 (only the motor).
What gave you that idea?
>Why not?
>Actually the energy content of 1 kg of hydrogen to produce electricity
>to drive a car costs me the gasoline equivalent of 20 Euros.
We've just been through that. It's a bogus assertion.
>Actually I will save money because won't be driving a 165 kw
>gasoline beast and I should be driving a modest 50-65 kw economic
>no-pollution car.
If you're going to play that game, you have to compare your hydrogen car to
an economical hybrid car. You can pick and choose crappy gas vehicles (such
as an oversized SUV) that do worse than the fuel cell prototypes, but guess
what - Toyota and Honda have moved the bar. A LOT. And they're going to keep
moving it.
>Unfortunately there won't be any fuel cell formula 1 racing cars.
That's because fuel cells are klunky, inefficient, and heavy, and are
handicapped by heavy complex fuel storage. Electric vehicles on the other
hand, can blow the doors off of gas vehicles.
The point here is simple. Nobody's saying we should stay on gas forever,
but hydrogen isn't anywhere near a viable alternative. What should be
happening is that everyone should be buying hybrids. Doing that would cut
fuel use more than in half right off the bat, and with all the auto makers
working to squeeze more and more out of them as demand increases, oil use
will go down every year. Hydrogen is an excuse to do nothing. *
--
* PV something like badgers--something like lizards--and something
like corkscrews.
.
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