Displacing the Carbon energy economy with long term PV.. just the facts..
T.Keating
ONLY the most up to date current and future trends. (Inefficient,
wasteful, and obsolete technologies have no place in our energy
future.)
Modern PV cell tech uses silicon wafers with thicknesses under 200um.
Density of Si is around 2.33g/cm^3
The standard PV cell dimensions are 125mm *125mm * thickness..
Thus a kilogram of silicon yields a square block approximately
12.5cm (W) * 12.5cm(L)* 2.75cm(H).. "
some prelim calc figures..
or 27.5 mm (H) / 0.3mm == 91.6 cells (10.9g per cell)
or 27.5 mm (H) / 0.2mm == 137.5 cells (7.3g per cell)***
or 27.5 mm (H) / 0.15mm == 183.3 cells (5.45g per cell)
Notes:
12.5cm^2 solar cell is exposed to 15.6 watts at std
isolation(1000W/m^2 ) *.15(15% conversion eff) == 2.35 watts..
Ribbon process doesn't involve any wafer splitting.
Ignot source requires wafer cutting, but wafers thickness is down to
150 to 200um range, with cutting process consuming 70 to 100um of Si
material(recycled).
***Using mid range tech of 0.20mm cell thickness, (recycling waste Si)
2.35watts per cell * 137.5 == 323watts per kg.
===========
Average flat panel solar flux for the US lower 48 angled at latitude
is 4.6 kWh/M^2/day.
http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/colorgifs/208.GIF
(Flat Plate Tilted South at latitude.)
Only a fool would construct them in a location with below average solar
flux or mount them in horizontal flat orientation. (Covering maximum
surface area is NOT a requirement NOR is it desirable).
The following chart/map when compared to the others demonstrates how
much energy production one would loose by making a substandard mounting
decision.
http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/colorgifs/325.GIF
(Flat plate oriented horizontally with the earth.. no tilt)
A significantly better location for large scale PV energy production is
the desert SW with 9 to 10kWh/M^2/day of tracked solar flux(annual).
(323 watts of PV @ 9kWh/M^2/day == 2.9kWh day/kg of Sit.
http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/colorgifs/169.GIF
(Flat plate with dual axis tracker.)
(Notice the large area in the SW with 8 to 10 kWh/M^2/day production.)
In the end.. the energy payback for the initial SiO2 ->mgSi step using
tracked PV in desert SW is somewhat less than a week.. (3 to 5 days
depending on tech used)...
Wasteful, ultra pure IC grade silicon used for PV production is being
phased out for cheaper alternatives. (It's really not needed
anymore).
=====
As for carbon consumption..
To replace the 3883 billion kWh (2003) of electricity generated in
US(2003) would require a ONE TIME investment of 3883e+9 kWh/ 365 /
(2.9 kWh/kg) == 3.6 Million metric tons of refined Si..
Carbon (coal) needed to refine this amount of SI from SiO2 would be
3.6e+9 kg /28 * 12 == 1.5e+9 kg C or 1.5Million metric tons..
1.5 Million metric tons of C represents..(0.026%) or less than ONE
THOUSANDTH of the US's annual carbon consumption.
http://www-cta.ornl.gov/data/tedb25/Spreadsheets/Table11_04.xls
"U.S. Carbon Emissions from Fossil Energy Consumption"
2003..... 5,781.4 Million Metric tons of Carbon.
Imagine that... Just ONE day's worth of carbon usage dedicated towards
PV manufacturing could chop US annual carbon emissions by more than
40%. A little conservation(*) and transitioning to EV's could chop
off another 40%. (Using 15% of 3883B kWh PV output would propel 150
Million EV's for ~20K miles per year. (@~194wH per mile) ).
Notes:
Huge amounts of raw materials & energy, (consumed by the existing
fossil fuel industries), would be conserved.. (ships, mines, ports,
drilling rigs, pipelines, trucks, tankers, railroads, fueling stations,
and other infrastructure.. mostly gone.. reduced by 90%.. and with any
luck.. recycled).
* We will still have other forms of renewable energy production (wind,
hydro), plus backup storage in the forms of, anticipatory load
management, excess EV battery capacity, and combined cycle gas turbine
plants fueled by H2.
H2 can be efficiently produced using a two step process, which
combines a high yielding solar thermal energy component (60%), with a
greatly reduced electrical energy input(~40% 0.6v) per unit of energy
embodied in H2.
=======
Lastly... Long term PV production is a based on a renewable energy
source. Very little mass of a large scale PV plant (>10GW peak) is
consumed(lost) during a PV panel's/trackers operational lifetime..
Some erosion, some grease for the gears on the tracking mechanism, and
some makeup oil for hydraulic pump & piston.
At the end of PV panel lifespan, ALL of it can all be recycled, on
site, making new panels and trackers.
Collection and transportation energy costs near zero !
Separation energy costs near zero..
Clear PV grade Glass. ~80% energy savings..
Aluminum. ~95% energy savings.. (verses ~15kWh/kg for new Al
production.)
Silicon.. ~90% energy savings..
etc..
I.E. Higher initial energy investment (*),
but long term energy production sustainability (>100 years)
shifts dramatically towards the side of renewables. EROEI greater than
200 to 1....
* -- (Depends where the materials come from.. Each year the US
misplaces 48% or 0.633 million metric tons of Aluminum used to make
soda cans because someone was too lazy to recycle them.)
http://www.aluminum.org/Content/NavigationMenu/News_and_Stats/Statistics_Reports/Facts_At_A_Glance/factsataglance05.pdf
=====
In summary.. PV as useful energy source that is progressing at a rapid
rate..
Ultimately, It may not take on the exact characteristics as
described in this post.
But, I suspect, it will take a similar form...
The long term EROEI aspects of this solution(>100years) most likely
precludes day to day profit driven entities(mega corps) from being part
of the solution.
Thus it is up to the citizens of the world to force our governments
to act on our behalf for the COMMON GOOD and our future generations.
Brad Guth
news:1167154682....@h40g2000cwb.googlegroups.com
> Ultimately, It may not take on the exact characteristics as
> described in this post.
> But, I suspect, it will take a similar form...
> The long term EROEI aspects of this solution(>100years) most likely
> precludes day to day profit driven entities(mega corps) from being part
> of the solution.
> Thus it is up to the citizens of the world to force our governments
> to act on our behalf for the COMMON GOOD and our future generations.
Lord Exxon and of their all-knowing and extremely brown-nosed minions
like wizard Mook do not like you, do they.
I've got a perfectly super ideal application for those (made in China)
nearly full spectrum PV cells. Interested?
-
Brad Guth
--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG
stcfarms
band of wavelengths from the sun are turned into electricity, the rest
of the wavelengths are wasted producing heat. A 5 terawatt
geostationary orbit solar furnace could produce enough hydrogen to fuel
the world. If the output of the furnace was aimed at a diffraction
grating the wavelengths could be separated. Each wavelength could be
used where it is most effective, some would even go to PV cells.
Dan Bloomquist
stcfarms wrote:
> PV is fine as far as it goes but it is inefficient as only a narrow
> band of wavelengths from the sun are turned into electricity, the rest
> of the wavelengths are wasted producing heat....
Christ and all you idiots. It is about bucks/watt, nothing else. Usenet
is lost to highschool losers anymore..........
SJC
"Dan Bloomquist" <publ...@lakeweb.com> wrote in message news:lmJkh.8572$ya1....@news02.roc.ny...
R.H. Allen
> First off, let me premise this discussion in that it will only consider
> ONLY the most up to date current and future trends. (Inefficient,
> wasteful, and obsolete technologies have no place in our energy
> future.)
>
> Modern PV cell tech uses silicon wafers with thicknesses under 200um.
The thinnest available production technologies do (e.g., Sunpower), but
most commercial cells are still in the 220-250 µm range. While some
companies are trying to push below 200 µm now, the industry average is
not expected to be that low for several years yet.
> The standard PV cell dimensions are 125mm *125mm * thickness..
Since you want to focus on future trends you might bump your wafer size
up to 150 mm (or even 200 mm). Large wafers are an excellent way to
reduce manufacturing cost and you'll see a lot more wafers of these
sizes in the coming years. Quite a few manufacturers are already using
150 mm wafers, and somebody -- I think it was either Sharp or Kyocera --
has been flirting with 200 mm (it may, in fact, already be in production).
> Ignot source requires wafer cutting, but wafers thickness is down to
> 150 to 200um range, with cutting process consuming 70 to 100um of Si
> material(recycled).
Your numbers for this are *way* on the optimistic side. The wires used
to saw the wafers are themselves typically 160 µm or more, with
diameters smaller than 140 µm not even in the picture yet. The silicon
carbide grit used during the cutting process adds another 40-60 µm, so
that most wafering processes waste somewhere around 200 µm per wafer.
Currently there is no economical way to recycle this waste, so it is
simply tossed out. There are at least three different programs trying to
develop ways to recycle it economically, though, so over the next five
years you'll probably see it begin to be recycled (though the amount of
waste probably won't drop below about 160-180 µm/wafer).
Other wafering techniques that would reduce or eliminate kerf loss are
under development, but for commercial production some 99+% of sawn
wafers are cut with wire saws and subject to the limitations I outlined
above.
> Average flat panel solar flux for the US lower 48 angled at latitude
> is 4.6 kWh/M^2/day.
>
> http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/colorgifs/208.GIF
> (Flat Plate Tilted South at latitude.)
>
> Only a fool would construct them in a location with below average solar
> flux or mount them in horizontal flat orientation. (Covering maximum
> surface area is NOT a requirement NOR is it desirable).
Well then you've just ruled out the northeastern US. That's too bad
because despite the lower-than-average insolation, that's going to be
one of the first parts of the country where PV will be economically
competitive with retail rates.
Dan Bloomquist
SJC wrote:
<snip>
The usenet cop is back.........
zzbu...@netscape.net
T.Keating wrote:
> First off, let me premise this discussion in that it will only consider
> ONLY the most up to date current and future trends. (Inefficient,
> wasteful, and obsolete technologies have no place in our energy
> future.)
>
> Modern PV cell tech uses silicon wafers with thicknesses under 200um.
> Density of Si is around 2.33g/cm^3
Whch is why that's France's energy future,
Since history has recorded that the Neanderthal Region
is the only region of Earth that is known
to be recursive PBS slaves, rather than
regular slaves.
Joe Fischer
>T.Keating wrote:
>> First off, let me premise this discussion in that it will only consider
>> ONLY the most up to date current and future trends. (Inefficient,
>> wasteful, and obsolete technologies have no place in our energy
>> future.)
>>
>> Modern PV cell tech uses silicon wafers with thicknesses under 200um.
>
>The thinnest available production technologies do (e.g., Sunpower), but
>most commercial cells are still in the 220-250 µm range. While some
>companies are trying to push below 200 µm now, the industry average is
>not expected to be that low for several years yet.
The thinner a brittle material is, the easier it breaks,
that is probably the limiting factor in practice.
>> The standard PV cell dimensions are 125mm *125mm * thickness..
>
>Since you want to focus on future trends you might bump your wafer size
>up to 150 mm (or even 200 mm). Large wafers are an excellent way to
>reduce manufacturing cost and you'll see a lot more wafers of these
>sizes in the coming years. Quite a few manufacturers are already using
>150 mm wafers, and somebody -- I think it was either Sharp or Kyocera --
>has been flirting with 200 mm (it may, in fact, already be in production).
Yes, there is at least one plant in Asia that produces
exclusively 8 inch cells.
>> Ignot source requires wafer cutting, but wafers thickness is down to
>> 150 to 200um range, with cutting process consuming 70 to 100um of Si
>> material(recycled).
>
>Your numbers for this are *way* on the optimistic side. The wires used
>to saw the wafers are themselves typically 160 µm or more, with
>diameters smaller than 140 µm not even in the picture yet. The silicon
>carbide grit used during the cutting process adds another 40-60 µm, so
>that most wafering processes waste somewhere around 200 µm per wafer.
>Currently there is no economical way to recycle this waste, so it is
>simply tossed out. There are at least three different programs trying to
>develop ways to recycle it economically, though, so over the next five
>years you'll probably see it begin to be recycled (though the amount of
>waste probably won't drop below about 160-180 µm/wafer).
And it takes a lot of time, the original article seemed
to consider wafer raw material the same way aluminum or
steel can just be heated, rolled, and cut to size.
It does seem frustrating that single crystal silicon
production has not increased more rapidly, but maybe
with more exotic materials being use more it won't matter.
>Other wafering techniques that would reduce or eliminate kerf loss are
>under development, but for commercial production some 99+% of sawn
>wafers are cut with wire saws and subject to the limitations I outlined
>above.
And there is probably some lost material to breakage.
>> Average flat panel solar flux for the US lower 48 angled at latitude
>> is 4.6 kWh/M^2/day.
>>
>> http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/colorgifs/208.GIF
>> (Flat Plate Tilted South at latitude.)
>>
>> Only a fool would construct them in a location with below average solar
>> flux or mount them in horizontal flat orientation. (Covering maximum
>> surface area is NOT a requirement NOR is it desirable).
>
>Well then you've just ruled out the northeastern US.
The higher the latitude, the more reason to
mount them vertically or at an angle.
>That's too bad
>because despite the lower-than-average insolation, that's going to be
>one of the first parts of the country where PV will be economically
>competitive with retail rates.
I don't see competition with grid rates as the big
factor in deciding to install PV.
Areas where grid power is unavailable or not
dependable will surely be looking for alternate power
of some kind.
A man asked me yesterday about how many
watts an Amp is and was on his way to home depot
to buy an inverter to hook to his car battery to power
the house if the grid failed.
I would have liked to suggest PV, but all I
could suggest is a grid charger battery bank, an
inverter and automatic transfer switch.
But like 80 percent of people, he replied that
more than one battery is too expensive, so he
decided to shop for an emergency generator to
have just in case.
He is a farmer and has a tractor with a power
takeoff, and could use a 15k or even a 25k generator
powered by the tractor, and all he would need would
be a manual transfer switch, but the least money
possible is what is driving decisions.
Joe Fischer
The Ghost In The Machine
<tkgo...@ktcnslt.com>
wrote
on 26 Dec 2006 09:38:02 -0800
<1167154682....@h40g2000cwb.googlegroups.com>:
> First off, let me premise this discussion in that it will only consider
> ONLY the most up to date current and future trends. (Inefficient,
> wasteful, and obsolete technologies have no place in our energy
> future.)
PV has a problem. Currently, it costs maybe $6/W to
construct using *existing* energy cost structures. If one
assumes a PV can exist for 20 years that gives an energy cost
of about $0.30/W. That's mostly initial construction costs,
though one might factor in washing them once a quarter.
http://www.coaleducation.org/Ky_Coal_Facts/electricity/average_cost.htm
suggests an average of $0.0762 cents/kWh. This is obviously going to
be hard to compare but let's see what I can do.
Over an assumed 20-year lifetime of the plant the solar
plant's production will be variable, but if we assume 12
hours per day sunlight over the year (which is probably
only true near the equator) that gives me 87.6852 kWh
over that lifetime. In other words, that 1W PV plant will
generate that much energy before going kaput.
Because the PV is largely construction costs, we divide, giving
$6 / 87.6852 = $0.0684 cents/kWh.
Bear in mind this assumes *absolutely perfect* conditions, which will
never be realized in practice.
A more reasonable analysis is at
http://linas.org/theory/solar-electric.html
which calculates $0.415/kWh for a polycrystalline PV system
in Austin, TX. Not good unless one can guarantee a 100 year lifetime or
so.
Bear also in mind how that PV is being constructed. If one assumes $6/W
using existing energy structures, the price will go up to about $32.7/W
under new energy structures which assume pure PV power only.
We won't be able to solve this problem until we can lower this cost
or increase plant lifetime. I for one would hope for the latter.
Bear in mind here that if one tilts the panels one does get more energy
*per panel* but one also has to space the panels so that one panel's
shadow doesn't obscure another panel. Can't win that way!
>
> The following chart/map when compared to the others demonstrates how
> much energy production one would loose by making a substandard mounting
> decision.
>
> http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/colorgifs/325.GIF
> (Flat plate oriented horizontally with the earth.. no tilt)
>
> A significantly better location for large scale PV energy production is
> the desert SW with 9 to 10kWh/M^2/day of tracked solar flux(annual).
> (323 watts of PV @ 9kWh/M^2/day == 2.9kWh day/kg of Sit.
>
> http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/colorgifs/169.GIF
> (Flat plate with dual axis tracker.)
> (Notice the large area in the SW with 8 to 10 kWh/M^2/day production.)
>
> In the end.. the energy payback for the initial SiO2 ->mgSi step using
> tracked PV in desert SW is somewhat less than a week.. (3 to 5 days
> depending on tech used)...
>
> Wasteful, ultra pure IC grade silicon used for PV production is being
> phased out for cheaper alternatives. (It's really not needed
> anymore).
I for one certainly hope so. I'd want $1.5 - $2/W ideally.
Not sure why "on site" recycling would be required. Did one want to
build a Si refinery near every power plant?
--
#191, ewi...@earthlink.net
Linux sucks efficiently, but Windows just blows around
a lot of hot air and vapor.
--
Posted via a free Usenet account from http://www.teranews.com
T.Keating
<ew...@sirius.tg00suus7038.net> wrote:
>In sci.environment, T.Keating
><tkgo...@ktcnslt.com>
> wrote
>on 26 Dec 2006 09:38:02 -0800
><1167154682....@h40g2000cwb.googlegroups.com>:
>> First off, let me premise this discussion in that it will only consider
>> ONLY the most up to date current and future trends. (Inefficient,
>> wasteful, and obsolete technologies have no place in our energy
>> future.)
>
>PV has a problem. Currently, it costs maybe $6/W to
>construct using *existing* energy cost structures. If one
>assumes a PV can exist for 20 years that gives an energy cost
>of about $0.30/W. That's mostly initial construction costs,
>though one might factor in washing them once a quarter.
The problem is that the non-renewable energy sources is that they start
out by cost shifting their pollution burdens onto the commons.
Unfortunately those costs are coming right back at us in the form of
global climate change.
First to go.. 70% of the agriculture in coastal states.. despite the
current El-nino protecting the U.S., it's only temporary and it's
allowing the gulf waters to get warmer than ever. Once the el-nino
effect disappears, a near continuous on onslaught of major hurricanes
will put an end to the growing of those fragile crops.
=====
The cost shifted enviromental/defense burden for Oil consumed in the US
is around 670$ per barrel.. ref to previous cost est..
http://groups.google.com/group/alt.energy/msg/9b8d56307e686653
Burning coal represents at least 36% of our CO2 emissions in 2005..
ftp://ftp.eia.doe.gov/pub/oiaf/1605/cdrom/pdf/ggrpt/057305.pdf
(Table 5.. Not accounting for all the mining, transporting, and related
infrastructure which could tack on another 5%.)
And using the same environment cost criteria outlined for Oil.. (500T$
over 50 years. or 10T$ per year or 3.6T$ contribution for coal's
impact.. ) (3.6T$yr / 584 million metric tons of C in coal or 6.16$
per kg of coal burned.)
>
>http://www.coaleducation.org/Ky_Coal_Facts/electricity/average_cost.htm
>
>suggests an average of $0.0762 cents/kWh. This is obviously going to
>be hard to compare but let's see what I can do.
Using this link as one + previous eia link as references for coal&
related carbon usage in US electrical generation.
http://www.eia.doe.gov/neic/brochure/elecinfocard.html
yields a 2005 environmental impact cost of
(1944.2 / 44 * 12 == 530 million metric tons of C in coal used to
produce electric power. Average C content in Coal ~55%.
[530 B kg of C *6.16$ per kg of C environmental cost ] / [4055 B kWh *
49.7%(coal)] == 1.61$ per kWh in shifted costs in order to produce
electricity using coal.
Yup.. Coal's hidden enviromental cost is 1.61$ per kWh.. now you can
change the base line assumption.. decrease it by a factor 5x.. to 100T$
of irreversible current and projected damages over the next fifty years
(2T$/yr). But that still leaves you at 32 cents per kWh in hidden
costs.
However.. I feel that my do nothing 500T$ projection is somewhat more
accurate.. Once climate change positive feedbacks start kicking in..
Well, what price(value) do you place on the human race ????
== Cost of non-existent clean coal tech=====
Try produced energy using by coal that produces with little or no
emissions.. (which doesn't exist.. yet). (I.E. One must compare apples
to apples. "dirty" verses "clean" is not a valid comparison)
Additionally, don't forget to add in the lag time to construct all new
generation facilities.. The existing ones won't do. And the emissions
to build, operate a mine, train, tracks, underground storage to
sequester huge amounts of C02.
Oh.. let's not forget about coal plant cost per watt delivered..
An similar aspect which is always pointed out for PV installations.
2004 Construction cost of Coal power plant was $1300 per kilowatt.
http://en.wikipedia.org/wiki/Fossil_fuel_power_plant
or $1.30 per watt. A 2004 number which is likely to increase
dramatically once gas gassification and/or other types of pollution
controls are installed to sequester CO2 emission..
Adding in summertime capacity deration and utilization into those
costs.
$1.30 * (1/.72) * (107) == $1.93 per watt (not including Fuel &
it's transportation Costs)..
Verses 3 to $4 per equivalent watt for PV with 2 to 3x higher peak
output and NO additional Fuel or transportation costs.
(note: PV costs are dropping.. existing non-renewable tech is getting
more expensive..)
More refs filling in the details can be found at
http://groups.google.com/group/alt.energy.renewable/msg/7247fe9725ce11f8
And lastly.. what happens if the sequestered CO2 escapes in large
quantities?? Are you going end up asphyxiating an entire county or
two???
>
>Over an assumed 20-year lifetime of the plant the solar
More like 30 to 40 years.. Tracking has it's advantages..
It can be used to minimise weather based stresses on the panels.
Once the recycling interval starts costs per W drops (big time).
(Nearly all the raw materials are bought and paid for..
same goes for the energy content. )
>plant's production will be variable, but if we assume 12
>hours per day sunlight over the year (which is probably
9 kWh/M^2/day is the assumption.
>only true near the equator) that gives me 87.6852 kWh
>over that lifetime. In other words, that 1W PV plant will
>generate that much energy before going kaput.
>
>Because the PV is largely construction costs, we divide, giving
>$6 / 87.6852 = $0.0684 cents/kWh.
I bet you dollars to donuts.. you can do a lot better than $6 per watt
when one is
manufacturing 1GW of PV annually. Actual material costs.. ~10cents per
peak watt.
Energy costs.. well that's going to be a NOP. Throw in a whole
dollars worth of labor & losses per watt. (I.E. you've just
eliminated several middle men, so those costs are going to be even
lower. Back in 2003, name brand PV panels were selling for less than
$3/watt).
Material costs drop to near zero when recycling kicks in..
First run.. (30 year lifespan)..
$1.20 / 98.5 kWh (1wh * 9h * 365* 30y) = 0.012$ per kWh...
(40 year lifespan)..
$1.20 / 131.5 kWh (1wh * 9h * 365 * 40y) == 0.009$ per kWh.
Recycling phases starting 30 to 40 years out.. mostly labor.
20% lower yet again.. probably much lower..
(Greatly reduced need for the importation of additional materials.)
.......
I see you gave coal a free ride on construction and major overhaul
costs (let's not forget about fuel and pollution costs)
(Just on construction and major overhaul costs... which are not
fixed..)..
$1.30 per watt + (major overhauls every 2 years.. @200 mill, life span
32 years.. ). ==
$4.30 per watt / [(1 * 365 * 24 * 32) * .72 utilization factor /
(average deration factor 1.04)] ==
$4.30 per watt / 194 kWh == 0.022$ per kWh.. (not including fuel cost,
waste disposal, fuel transportation charges, and normal operating
costs.)
How about the cost to constuct the railroad, bridges all the way to the
power plant.
Same goes for the mining equipment, and those 400 ton trucks don't come
cheap, neither does the conveyor belt and the loading silo..
>Bear in mind this assumes *absolutely perfect* conditions, which will
>never be realized in practice.
>
>A more reasonable analysis is at
>
>http://linas.org/theory/solar-electric.html
>
>which calculates $0.415/kWh for a polycrystalline PV system
>in Austin, TX. Not good unless one can guarantee a 100 year lifetime or
>so.
Assuming retail prices, small scale, invalid power output calculation,
no recycling,. poor mounting choice.
All of which are dumb assumptions if one is intent on repowering our
society using renewables.
With on site recycling, original materials should last 20
generations(5% loss per reuse cycle) or an average of 300 to 400 years.
>
>Bear also in mind how that PV is being constructed. If one assumes $6/W
>using existing energy structures, the price will go up to about $32.7/W
>under new energy structures which assume pure PV power only.
Only if you continue to use bogus numbers..
Price will go down.. since energy payback occurs using generated
power.
>
>We won't be able to solve this problem until we can lower this cost
>or increase plant lifetime. I for one would hope for the latter.
Problem sovled.. run the correct numbers..
no.. PV panels don't shadow one another on a tracker, as the entire
tracking unit is always
facing towards the sun.
One spaces out each tracking array from each other(1 to 6 ratio). The
panels remain fairly packed on the tracker (1 or 2" gap. no more).
Desert land is very cheap.. Spacing them out is not only desireable,
but preferred.. (less environmental impact.. allows dual use of land
underneath..)
>> 1.5 Million metric tons of C represents..(0.095%) or less than ONE
>> THOUSANDTH of the US's annual carbon consumption.
^^^^^ statement revised for CO2 ratio.^^^^^^
>>
>> http://www-cta.ornl.gov/data/tedb25/Spreadsheets/Table11_04.xls
>> "U.S. Carbon Emissions from Fossil Energy Consumption"
>> 2003..... 5,781.4 Million Metric tons of Carbon.
(Missed a note in lines 2 thru 5.. that table is measure in tons of
CO2.. not pure C)..
At least enough refining to produce solar grade silicon from medical
grade Silicon.
Clustering three 10 GWe solar PV plants together would require 1GW
production of PV + tracking per year.. After thirty years, they start
recycling the oldest panels & trackers.
Joe Fischer
>The problem is that the non-renewable energy sources is that they start
>out by cost shifting their pollution burdens onto the commons.
>Unfortunately those costs are coming right back at us in the form of
>global climate change.
Possibly, but not a given.
Frankly I find the hysteria by some to be remarkable,
and in some cases obviously exaggerated.
> First to go.. 70% of the agriculture in coastal states.. despite the
>current El-nino protecting the U.S.,
How does that happen? In some states that
has not been unusual in the past, by both drought and
floods.
>it's only temporary and it's
>allowing the gulf waters to get warmer than ever.
Weren't the gulf waters cooler this past summer,
did I miss some hurricanes?
>Once the el-nino
>effect disappears, a near continuous on onslaught of major hurricanes
>will put an end to the growing of those fragile crops.
Did you see "The Omen", I missed it.
>=====
>The cost shifted enviromental/defense burden for Oil consumed in the US
> is around 670$ per barrel.. ref to previous cost est..
>http://groups.google.com/group/alt.energy/msg/9b8d56307e686653
Check you calculator, if I used 20 barrels last
year, I owe somebody $13,000?
> Burning coal represents at least 36% of our CO2 emissions in 2005..
>ftp://ftp.eia.doe.gov/pub/oiaf/1605/cdrom/pdf/ggrpt/057305.pdf
>(Table 5.. Not accounting for all the mining, transporting, and related
>infrastructure which could tack on another 5%.)
Burning natural gas releases enough water vapor
to cause big climate changes, or maybe the albedo of
clouds offsets the CO2?
>And using the same environment cost criteria outlined for Oil.. (500T$
>over 50 years. or 10T$ per year or 3.6T$ contribution for coal's
>impact.. ) (3.6T$yr / 584 million metric tons of C in coal or 6.16$
>per kg of coal burned.)
According to you, the end is near, but I didn't
see where you identified the damages, how can the
monetary damages be known without knowing the
physical damage?
That much physical damage must mean that
all personal and public property will be destroyed,
boy, we are really in bad shape.
>>http://www.coaleducation.org/Ky_Coal_Facts/electricity/average_cost.htm
>>
>>suggests an average of $0.0762 cents/kWh. This is obviously going to
>>be hard to compare but let's see what I can do.
>
>Using this link as one + previous eia link as references for coal&
>related carbon usage in US electrical generation.
>http://www.eia.doe.gov/neic/brochure/elecinfocard.html
>yields a 2005 environmental impact cost of
>(1944.2 / 44 * 12 == 530 million metric tons of C in coal used to
>produce electric power. Average C content in Coal ~55%.
>
> [530 B kg of C *6.16$ per kg of C environmental cost ] / [4055 B kWh *
>49.7%(coal)] == 1.61$ per kWh in shifted costs in order to produce
>electricity using coal.
And I used 2000 KWH in the last month, should
I have paid $3200 instead of the $178?
>Yup.. Coal's hidden enviromental cost is 1.61$ per kWh.. now you can
>change the base line assumption.. decrease it by a factor 5x.. to 100T$
>of irreversible current and projected damages over the next fifty years
>(2T$/yr). But that still leaves you at 32 cents per kWh in hidden
>costs.
I really think you have gone overboard, is anybody
else not a politico making these claims?
>However.. I feel that my do nothing 500T$ projection is somewhat more
>accurate.. Once climate change positive feedbacks start kicking in..
>Well, what price(value) do you place on the human race ????
Hasn't it already kicked in? Or should I ask
if water covering half of Florida is worse than glaciers
across France and Ohio?
>== Cost of non-existent clean coal tech=====
>Try produced energy using by coal that produces with little or no
>emissions.. (which doesn't exist.. yet). (I.E. One must compare apples
>to apples. "dirty" verses "clean" is not a valid comparison)
>
>Additionally, don't forget to add in the lag time to construct all new
>generation facilities.. The existing ones won't do. And the emissions
>to build, operate a mine, train, tracks, underground storage to
>sequester huge amounts of C02.
>
>Oh.. let's not forget about coal plant cost per watt delivered..
>An similar aspect which is always pointed out for PV installations.
I agree, the pessimists really stretch things, PV
is economical in many places and for various reasons,
and should be accelerated even if global warming turns
out to be false.
>2004 Construction cost of Coal power plant was $1300 per kilowatt.
>http://en.wikipedia.org/wiki/Fossil_fuel_power_plant
>
>or $1.30 per watt. A 2004 number which is likely to increase
>dramatically once gas gassification and/or other types of pollution
>controls are installed to sequester CO2 emission..
>
>Adding in summertime capacity deration and utilization into those
>costs.
> $1.30 * (1/.72) * (107) == $1.93 per watt (not including Fuel &
>it's transportation Costs)..
>
>Verses 3 to $4 per equivalent watt for PV with 2 to 3x higher peak
>output and NO additional Fuel or transportation costs.
>(note: PV costs are dropping.. existing non-renewable tech is getting
>more expensive..)
>
>More refs filling in the details can be found at
>http://groups.google.com/group/alt.energy.renewable/msg/7247fe9725ce11f8
A PV installation costs more than $4 a watt, but
in many places and for many reasons, it is worth it.
>And lastly.. what happens if the sequestered CO2 escapes in large
>quantities?? Are you going end up asphyxiating an entire county or
>two???
On the ISS they had to turn off the CO2 absorbers
for a while, the levels got too low for human health.
>>Over an assumed 20-year lifetime of the plant the solar
>
>More like 30 to 40 years.. Tracking has it's advantages..
> It can be used to minimise weather based stresses on the panels.
It may be more than that, most of the degradation
is crud on the surface.
>Once the recycling interval starts costs per W drops (big time).
>(Nearly all the raw materials are bought and paid for..
> same goes for the energy content. )
>
>>plant's production will be variable, but if we assume 12
>>hours per day sunlight over the year (which is probably
>
>9 kWh/M^2/day is the assumption.
I keep reading 5.
>>only true near the equator) that gives me 87.6852 kWh
>>over that lifetime. In other words, that 1W PV plant will
>>generate that much energy before going kaput.
>>
>>Because the PV is largely construction costs, we divide, giving
>>$6 / 87.6852 = $0.0684 cents/kWh.
>
>I bet you dollars to donuts.. you can do a lot better than $6 per watt
>when one is
>manufacturing 1GW of PV annually. Actual material costs.. ~10cents per
>peak watt.
>Energy costs.. well that's going to be a NOP. Throw in a whole
>dollars worth of labor & losses per watt. (I.E. you've just
>eliminated several middle men, so those costs are going to be even
>lower. Back in 2003, name brand PV panels were selling for less than
>$3/watt).
Maybe if supply goes up, price will go down
there is supposed to be a shortage, although I saw
a site the other day that offered all different sizes
and shapes.
>Material costs drop to near zero when recycling kicks in..
>
>First run.. (30 year lifespan)..
>$1.20 / 98.5 kWh (1wh * 9h * 365* 30y) = 0.012$ per kWh...
>
> (40 year lifespan)..
>$1.20 / 131.5 kWh (1wh * 9h * 365 * 40y) == 0.009$ per kWh.
>
>Recycling phases starting 30 to 40 years out.. mostly labor.
> 20% lower yet again.. probably much lower..
> (Greatly reduced need for the importation of additional materials.)
If your estimate of material cost of 10 cents per peak
watt is right, then recycling won't change anything.
>I see you gave coal a free ride on construction and major overhaul
>costs (let's not forget about fuel and pollution costs)
The power plants pay for the fuel, the noticeable
pollution is on my car and house.
>(Just on construction and major overhaul costs... which are not
>fixed..)..
>$1.30 per watt + (major overhauls every 2 years.. @200 mill, life span
>32 years.. ). ==
>$4.30 per watt / [(1 * 365 * 24 * 32) * .72 utilization factor /
>(average deration factor 1.04)] ==
>$4.30 per watt / 194 kWh == 0.022$ per kWh.. (not including fuel cost,
>waste disposal, fuel transportation charges, and normal operating
>costs.)
>
>How about the cost to constuct the railroad, bridges all the way to the
>power plant.
>Same goes for the mining equipment, and those 400 ton trucks don't come
>cheap, neither does the conveyor belt and the loading silo..
And is this argument just for PV, or both PV
and global warming?
Do we really need exaggerated claims to make
alternate, renewable, sustainable energy a goal?
>>Bear in mind this assumes *absolutely perfect* conditions, which will
>>never be realized in practice.
>>
>>A more reasonable analysis is at
>>
>>http://linas.org/theory/solar-electric.html
>>
>>which calculates $0.415/kWh for a polycrystalline PV system
>>in Austin, TX. Not good unless one can guarantee a 100 year lifetime or
>>so.
>
>Assuming retail prices, small scale, invalid power output calculation,
> no recycling,. poor mounting choice.
It is obviously an exaggeration, or at least suggests
more people should DIY.
>All of which are dumb assumptions if one is intent on repowering our
>society using renewables.
>
> With on site recycling, original materials should last 20
>generations(5% loss per reuse cycle) or an average of 300 to 400 years.
If controlled fusion is not possible by then,
PV and wind may not be enough, so some planning
for moving south may be needed.
>>Bear also in mind how that PV is being constructed. If one assumes $6/W
>>using existing energy structures, the price will go up to about $32.7/W
>>under new energy structures which assume pure PV power only.
>
>Only if you continue to use bogus numbers..
> Price will go down.. since energy payback occurs using generated
>power.
If the price just stays the same, PV will be better
than fossil fuels, but some fossil fuel will be needed, even
with much improved storage, there are too many cloudy
days to depend solely on solar.
>>We won't be able to solve this problem until we can lower this cost
>>or increase plant lifetime. I for one would hope for the latter.
>
>Problem sovled.. run the correct numbers..
Not solved unless production goes way up, not
for the price, but for the availability.
Some new technology is needed, using material
that is in better supply.
Joe Fischer
Solar Flare
"Joe Fischer" <j...@westpointracing.com> wrote in message
news:sr99p2h9fl2fkdgfs...@4ax.com...
R.H. Allen
> On Thu, "R.H. Allen" <kka...@hotmail.com> wrote:
>
>> T.Keating wrote:
>>>
>>> Modern PV cell tech uses silicon wafers with thicknesses under 200um.
>> The thinnest available production technologies do (e.g., Sunpower), but
>> most commercial cells are still in the 220-250 µm range. While some
>> companies are trying to push below 200 µm now, the industry average is
>> not expected to be that low for several years yet.
>
> The thinner a brittle material is, the easier it breaks,
> that is probably the limiting factor in practice.
Yes, that's true. The problem is solvable, but it involves a greater
degree of automation to enable handling of extremely thin wafers without
reducing yields to uneconomical levels. This puts small producers at a
disadvantage, since they often cannot afford high levels of automation,
but that will be less of a problem as the PV industry grows.
>>> Ignot source requires wafer cutting, but wafers thickness is down to
>>> 150 to 200um range, with cutting process consuming 70 to 100um of Si
>>> material(recycled).
>> Your numbers for this are *way* on the optimistic side. The wires used
>> to saw the wafers are themselves typically 160 µm or more, with
>> diameters smaller than 140 µm not even in the picture yet. The silicon
>> carbide grit used during the cutting process adds another 40-60 µm, so
>> that most wafering processes waste somewhere around 200 µm per wafer.
>> Currently there is no economical way to recycle this waste, so it is
>> simply tossed out. There are at least three different programs trying to
>> develop ways to recycle it economically, though, so over the next five
>> years you'll probably see it begin to be recycled (though the amount of
>> waste probably won't drop below about 160-180 µm/wafer).
>
> And it takes a lot of time, the original article seemed
> to consider wafer raw material the same way aluminum or
> steel can just be heated, rolled, and cut to size.
In the '70s somebody actually did produce silicon wafers via cold
rolling, though strictly as an experiment. It required something like 32
steps and was extremely expensive, so was quickly abandoned.
At any rate, I agree, wire sawing is a rather long batch process. Setup
and sawing time for 200 mm wafers is something like 8 hours. You get a
thousand or so wafers in that 8 hours, making it a whole lot faster than
other sawing techniques, but you have to wait until the end of the
process to have any wafers to work with.
>> Other wafering techniques that would reduce or eliminate kerf loss are
>> under development, but for commercial production some 99+% of sawn
>> wafers are cut with wire saws and subject to the limitations I outlined
>> above.
>
> And there is probably some lost material to breakage.
Absolutely. Wafer sawing is the lowest-yield part of the process.
> I don't see competition with grid rates as the big
> factor in deciding to install PV.
> Areas where grid power is unavailable or not
> dependable will surely be looking for alternate power
> of some kind.
Depends on where you are. In developing nations I would agree with you.
In industrialized nations like the US there are few areas that don't
have access to grid power -- far too few to drive a large PV industry. I
doubt PV has to achieve complete parity with grid pricing in
industrialized nations, but it does have to be reasonably competitive in
my opinion.
> but the least money
> possible is what is driving decisions.
Agreed, which is why I think grid-connected applications have to be
competitive with grid pricing.