New high end Solar Cell claims 42.8 % efficiency

[James Arthur]

It'd be nice. I wonder when it will get below, say, $1/KW.

Cheers!
Rich

In an effort to nail the thing down a little better I wrote a computer
model last night. Assumptions make all the difference, but just for
an example...

Assuming: (view in Courier)
initial system cost = $3/watt
solar cell + inverter cost = $2.50/watt
battery cost per system watt = $0.50 (probably too low)

battery life = 8 years
solar cell life = 25 years

inflation = 3.5%
interest rate = 6%

value of electricity = $0.14/kWh, rising at inflation rate

300 solar days per year
94% of solar power delivered to loads (i.e., wiring+converter
efficiency).
100% utilization of power generated (i.e. all is either used or sold
for full retail price)
100% battery efficiency


Results:
At the end of 25 years the system will be approximately used up.
As a consumer you will have gotten the value of the electricity
produced, and have $0.51 per watt in your pocket, a yield of about
0.6% on the investment.

Comment: a system without batteries that sells excess power on the
grid during daylight hours would cost less and return more.

With the same assumptions as above, a no-battery system would leave
you with $4.79 per watt in your pocket after 25 years, which,
including the value of kWh consumed, gives a yield of 4.38%

Cheers,
James Arthur

 

[John Popelish]

In an effort to nail the thing down a little better I wrote a computer
model last night. Assumptions make all the difference, but just for
an example...

Assuming: (view in Courier)
initial system cost = $3/watt
solar cell + inverter cost = $2.50/watt
battery cost per system watt = $0.50 (probably too low)

battery life = 8 years
solar cell life = 25 years

inflation = 3.5%
interest rate = 6%

value of electricity = $0.14/kWh, rising at inflation rate

300 solar days per year
94% of solar power delivered to loads (i.e., wiring+converter
efficiency).
100% utilization of power generated (i.e. all is either used or sold
for full retail price)
100% battery efficiency


Results:
At the end of 25 years the system will be approximately used up.
As a consumer you will have gotten the value of the electricity
produced, and have $0.51 per watt in your pocket, a yield of about
0.6% on the investment.

Comment: a system without batteries that sells excess power on the
grid during daylight hours would cost less and return more.

With the same assumptions as above, a no-battery system would leave
you with $4.79 per watt in your pocket after 25 years, which,
including the value of kWh consumed, gives a yield of 4.38%

I think the no battery, daylight grid booster approach will
be the first way solar power will become practical on a
large scale. I think there will have to be severe fuel
restrictions (huge price increases or legal impediments on
the burning of fossil fuels) before continuous output power
plants will start to be replaced by solar/battery systems.

 

[Eeyore]

I think there will have to be severe fuel restrictions (huge price increases
or legal impediments on
the burning of fossil fuels)

The 'greens' would love that ! Compulsion seems to be their preferred way.

And to think that not long ago I was a Greenpeace member. They ought to stick to
saving whales, seals, rainforests and the like.

before continuous output power
plants will start to be replaced by solar/battery systems.

I can't ever see batteries being a sensible method for storage of everyday
electrical power. Batteries simply 'wear out' too fast.

Graham

 

[Eeyore]

I wish people would announce breakthroughs when they start to be practical.

'Greens' don't seem to feel constrained by such sensible ideas.

Graham

 

[Jon Slaughter]

http://www.physorg.com/news104501218.html
Team sets solar cell record
Using a novel technology that adds multiple innovations to a very
high-performance crystalline silicon solar cell platform, a consortium led
by the University of Delaware has achieved a record-breaking combined
solar cell efficiency of 42.8 percent from sunlight at standard
terrestrial conditions.

[snip]

Robert H.

So what are the long term effects? If ~50%? of the solar energy that
normally be reflected back out into space is used to create electricity
which ultimately will end up as heat, doesn't this mean that global warming
will become a reality very quickly?

Ok, I know the 50% figure above is wrong as most of the energy is reflected
back before it reaches ground. But what would be a good estimate? 1%? Now
if everyone replaced there energy consumption with solar cells then what
would be the equivilent ambient temperature increase? Isn't it the same
increase one would have with current methods?

i.e., it seems we can easily estimate the world's current energy
consumptions on global warming? We might not know how much fossil fuel
consumption plays a part but surely we know with solar cells? and we can
make an equivilence between the two. Knowing how much extra solar energy
that is not going to be absorbed should give an easy estimate on the
increase in temperature.

I'm just rambling here but seems to me if everyone used solar cells, not
even taking into account all the energy and materials required to
manufacture them, just the amount of solar energy being absorbed by them
would increase global temperature quite easily? Now if thats the case then
obviously thats whats happening with fossil fuels because its just a
different method. (while its not a direct equivilence I would imagine its
not to far off)

Seems like an easy way to estimate if global warming is actually happening
or not and I've not read an argument along those lines. Although I suppose
one could estimate the amount of energy used per capita and convert that
into heat and compare it to the energy from the sun. i.e., the real issue in
global warming is just how much energy we used compared to what the sun
"gives" us. The first one we can control while the second we cannot. (so, if
its 1/10^6, say, then chances are there is no global warming... or if it is,
then its out of our control)

Anyways, I'm sure theres been some research along those lines, anyone know
of the results?

Jon

 

[Rich Grise, Plainclothes Hippie]

The 'greens' would love that ! Compulsion seems to be their preferred way.

And to think that not long ago I was a Greenpeace member. They ought to
stick to saving whales, seals, rainforests and the like.

Yeah - when did they flip-flop from loving the rainforests to wanting them
to die of suffocation? ;-)

Cheers!
Rich

 

[John Popelish]

So what are the long term effects? If ~50%? of the solar energy that
normally be reflected back out into space is used to create electricity
which ultimately will end up as heat, doesn't this mean that global warming
will become a reality very quickly?

(snip)

So called global warming is caused by changes in the
composition of the atmosphere that slow the escape or
infrared radiation into space. Right now, 100% of the
radiation that reaches the surface is either bounced back as
visible or raises the temperature of the surface. that
energy must convect away, or radiate away as long wave IR
radiation. Swapping the natural surface for solar cells
bounces little back as visible radiation, because the cells
are generally pretty dark.

But about half of the radiation that penetrates their
surfaces is converted to electrical energy and half raises
the temperature of the cells, just like what happens to
dirt. The 50% converted to electricity actually lowers the
temperature rise of the cells, but that doesn't lower the
total IR radiation, because it is just transported elsewhere
and radiated away, there.

The net effect with or without solar cells is a wash, except
that people get to run appliances off the energy before it
leaves into space. If instead, those appliances are run off
fossil fuel, their heat is added to what the dirt in
sunlight produces, except that the burnt fuel gets added to
the atmosphere, getting in the way of the natural and waste
heat escaping into space. Either way, solar energy
overwhelms any addition from fuel consumption, as far as the
amount of heat to be radiated. The big difference is in the
composition of the atmosphere that heat has to pass through,
to escape.

For the last few decades, we have been pumping several
million barrels of oil out of the Earth, every day, and
setting fire to it. That is a lot of carbon added to the
atmosphere, and carbon dioxide in the atmosphere in the form
of carbon dioxide, is very absorbent in the long wave IR
part of the spectrum, where all that natural and wast heat
is being radiated. As the CO2 builds up it raises the
temperature of the atmosphere which raises the equilibrium
water vapor content in the atmosphere. Water vapor is
another IR absorbing gas, positive feedback takes over at
some point and the system swings rapidly to a very much
hotter equilibrium temperature, world wide. That is the so
called global warming process (originally called global
thermal run away, before the oil companies renamed it), in a
nut shell.

 

[Jim Thompson]

(snip)

So called global warming is caused by changes in the
composition of the atmosphere that slow the escape or
infrared radiation into space. Right now, 100% of the
radiation that reaches the surface is either bounced back as
visible or raises the temperature of the surface. that
energy must convect away, or radiate away as long wave IR
radiation. Swapping the natural surface for solar cells
bounces little back as visible radiation, because the cells
are generally pretty dark.

But about half of the radiation that penetrates their
surfaces is converted to electrical energy and half raises
the temperature of the cells, just like what happens to
dirt. The 50% converted to electricity actually lowers the
temperature rise of the cells, but that doesn't lower the
total IR radiation, because it is just transported elsewhere
and radiated away, there.

The net effect with or without solar cells is a wash, except
that people get to run appliances off the energy before it
leaves into space. If instead, those appliances are run off
fossil fuel, their heat is added to what the dirt in
sunlight produces, except that the burnt fuel gets added to
the atmosphere, getting in the way of the natural and waste
heat escaping into space. Either way, solar energy
overwhelms any addition from fuel consumption, as far as the
amount of heat to be radiated. The big difference is in the
composition of the atmosphere that heat has to pass through,
to escape.

For the last few decades, we have been pumping several
million barrels of oil out of the Earth, every day, and
setting fire to it. That is a lot of carbon added to the
atmosphere, and carbon dioxide in the atmosphere in the form
of carbon dioxide, is very absorbent in the long wave IR
part of the spectrum, where all that natural and wast heat
is being radiated. As the CO2 builds up it raises the
temperature of the atmosphere which raises the equilibrium
water vapor content in the atmosphere. Water vapor is
another IR absorbing gas, positive feedback takes over at
some point and the system swings rapidly to a very much
hotter equilibrium temperature, world wide. That is the so
called global warming process (originally called global
thermal run away, before the oil companies renamed it), in a
nut shell.

I'm looking forward to climate change... can you imagine Arizona
10-15° cooler ?

...Jim Thompson

 

[John Larkin]

(snip)

So called global warming is caused by changes in the
composition of the atmosphere that slow the escape or
infrared radiation into space. Right now, 100% of the
radiation that reaches the surface is either bounced back as
visible or raises the temperature of the surface. that
energy must convect away, or radiate away as long wave IR
radiation. Swapping the natural surface for solar cells
bounces little back as visible radiation, because the cells
are generally pretty dark.

But about half of the radiation that penetrates their
surfaces is converted to electrical energy and half raises
the temperature of the cells, just like what happens to
dirt. The 50% converted to electricity actually lowers the
temperature rise of the cells, but that doesn't lower the
total IR radiation, because it is just transported elsewhere
and radiated away, there.

The net effect with or without solar cells is a wash, except
that people get to run appliances off the energy before it
leaves into space. If instead, those appliances are run off
fossil fuel, their heat is added to what the dirt in
sunlight produces, except that the burnt fuel gets added to
the atmosphere, getting in the way of the natural and waste
heat escaping into space. Either way, solar energy
overwhelms any addition from fuel consumption, as far as the
amount of heat to be radiated. The big difference is in the
composition of the atmosphere that heat has to pass through,
to escape.

For the last few decades, we have been pumping several
million barrels of oil out of the Earth, every day, and
setting fire to it. That is a lot of carbon added to the
atmosphere, and carbon dioxide in the atmosphere in the form
of carbon dioxide, is very absorbent in the long wave IR
part of the spectrum, where all that natural and wast heat
is being radiated. As the CO2 builds up it raises the
temperature of the atmosphere which raises the equilibrium
water vapor content in the atmosphere. Water vapor is
another IR absorbing gas, positive feedback takes over at
some point and the system swings rapidly to a very much
hotter equilibrium temperature, world wide. That is the so
called global warming process (originally called global
thermal run away, before the oil companies renamed it), in a
nut shell.

If water-vapor positive feedback were sufficient for the loop to run
away, it would have run away anyhow, CO2 or not. The water vapor loop
must be net *negative* feedback, probably because of clouds.

CO2 absorption is so small that the only way the GW enthusiasts can
get worked up is to apply a *lot* of conjectured "helper" positive
feedback mechanisms. And clearly (clearly to me, anyhow) if those
mechanisms existed 1000 years ago, they would have snapped then.

Earth is currently something like 20 degrees C below the temperature
of an equivalent spherical black body.

I read that, on average, water vapor absorbs as much reflected IR in
the first 30 feet as does all the CO2 from the ground to space.

John

 

[John Popelish]

Water vapor is

If water-vapor positive feedback were sufficient for the loop to run
away, it would have run away anyhow, CO2 or not. The water vapor loop
must be net *negative* feedback, probably because of clouds.

That is like saying that if a Schmitt trigger is capable of
snapping on a positive input, varying less positive signals
would have already have snapped it. The CO2 level is the
threshold setting. As long as it is below some limiting
concentration, the net feedback is negative, as you say.
Above some limiting concentration, the positive feed
feedback gets bigger than the negative feedback and the
system flips. That is the concept, anyway.

 

[Don Lancaster]

I'm looking forward to climate change... can you imagine Arizona
10-15° cooler ?

...Jim Thompson

The key point everybody has yet to pick up on is that the VARIABILITY
will also get a lot worse. Much worse.


--
Many thanks,

Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com

 

[John Larkin]

That is like saying that if a Schmitt trigger is capable of
snapping on a positive input, varying less positive signals
would have already have snapped it. The CO2 level is the
threshold setting. As long as it is below some limiting
concentration, the net feedback is negative, as you say.
Above some limiting concentration, the positive feed
feedback gets bigger than the negative feedback and the
system flips. That is the concept, anyway.

But the feedback is continuous, analog, not a sharp threshold. And
Earth has been a lot warmer in the past, with much higher CO2 levels.
If there were positive feedback, we'd still be in the latched-warm
state. If you look at the graphs of temp versus time over the last
million years, there are periodic hot spikes caused by solar influx,
but nothing that snaps or sticks.

GW is about political control; it the long-sought killer app of the
anticapitalist "environmental" movement.

John

 

[joseph2k]

'Greens' don't seem to feel constrained by such sensible ideas.

Graham

The "Greens" have no intention of tolerating proper development of any real
breakthrough.

 

[John Devereux]

But the feedback is continuous, analog, not a sharp threshold. And
Earth has been a lot warmer in the past, with much higher CO2 levels.
If there were positive feedback, we'd still be in the latched-warm
state. If you look at the graphs of temp versus time over the last
million years, there are periodic hot spikes caused by solar influx,
but nothing that snaps or sticks.

There are negative feedback loops too but they are much slower,
AIUI. For example the carbon in CO2 eventually ends up converted to
calcium carbonate by marine organisms, or into fossil fuels by
forests, but this takes thousands (or millions) of years. In the mean
time you can get melting of the icecaps & extinction events.

 

[Richard The Dreaded Libertarian]

Where can I find data that shows CO2 levels higher anytime in the last
million years higher than it is now (and rising)? The system may be
analog, but it is not linear. A couple degrees more, and Antarctic ice
slides into the ocean and sea levels pop up in a season. It has happened
several times in the past and it will happen again. It is not a question
of if, but only when. Our fossil fuel use is just pulling the trigger
sooner. If I had my choice, I would rather we delay the snap.

I'm rather looking forward to it - who knows, we might enjoy the ride! ;-)

It has latches in the past, but that raises water levels so much that,
eventually, the reflectivity of sea water swings the system back through
the snap.

Right. So it equilibrates. And it's going to happen anyway. What we really
need to do is prepare for it and learn how to live through it and get on
with our lives.

Right, it lasts only a few 1`0s of thousands of years. A moment in
geologic time.


Freeing ourselves from fossil fuel consumption will be the biggest boost
to capitalism since the locomotive.

Actually, getting rid of income taxes would be the biggest boost to
capitalism since, well, since capitalism itself. ;-)

If you're truly addicted to taxes, just replace it with a sales tax. You
buy a $3.00 toothbrush, you pay $0.30 tax. Well, maybe not health care
stuff, like not for grocery store food. But you get my point. Buy a
$3,000,000.00 boat, you pay $300,000.00 tax. There is no more fairly
distributed tax, if it's even possible to rationalize taxation as "fair"
at all.

The truth is, taxation is theft. It's just that simple. If you don't
believe me, try not paying your "voluntary" tax. They will take it by
force, which is pretty much the definition of theft.

Thanks,
Rich

 

[Richard The Dreaded Libertarian]

.

The question is whether we will do it before or after the south pole
melts. I have little hope left that we will get their first. I expect to
see it go within a decade... two at most.

This just goes to show that Al Gore and his disciples are quite insane.
They seem to believe that it's possible to stop the inevitable by
preaching from a soapbox.

Oh, well.

Thanks,
Rich

 

[Richard The Dreaded Libertarian]

.

There are negative feedback loops too but they are much slower, AIUI.
For example the carbon in CO2 eventually ends up converted to calcium
carbonate by marine organisms, or into fossil fuels by forests, but this
takes thousands (or millions) of years. In the mean time you can get
melting of the icecaps & extinction events.

Everyone seems to be totally sidestepping the fact that green plants
inhale CO2, and turn it into food. Ergo, the more CO2 in the air, and
the warmer it is, which translates to "longer growing season", means
more food for everyone!

So, global warming is a GOOD thing.

And, so what if the icecaps melt and our coasts are swamped? Who needs
New York, Miami, or LA anyway? >:->

Cheers!
Rich

 

[Ross Herbert]

I think the no battery, daylight grid booster approach will
be the first way solar power will become practical on a
large scale. I think there will have to be severe fuel
restrictions (huge price increases or legal impediments on
the burning of fossil fuels) before continuous output power
plants will start to be replaced by solar/battery systems.

The "no battery" method is quite common now. My daughter in the south
west of Western Australia has just installed a grid connected system
like this.

Personally, I would rather have a battery and sell any excess back to
the grid during the day and have my own power after the sun goes down.
I don't see any sense in having a solar power system if it doesn't
give me power ALL the time, especially when the majority of household
power is used after the sun goes down.

 

[John Larkin]

The "no battery" method is quite common now. My daughter in the south
west of Western Australia has just installed a grid connected system
like this.

Personally, I would rather have a battery and sell any excess back to
the grid during the day and have my own power after the sun goes down.
I don't see any sense in having a solar power system if it doesn't
give me power ALL the time, especially when the majority of household
power is used after the sun goes down.

In the US, we have a big early-afternoon peak, mostly air
conditioning. There's lots of excess, relative cheap generating
capacity available at night.

John

 

[Mark Zenier]

There are negative feedback loops too but they are much slower,
AIUI. For example the carbon in CO2 eventually ends up converted to
calcium carbonate by marine organisms, or into fossil fuels by
forests, but this takes thousands (or millions) of years. In the mean
time you can get melting of the icecaps & extinction events.

You can get the CO2 out of the atmosphere by just weathering and
erosion. That's what happened in the Snowball Earth era back 750
million years ago.

Back then, all the continents were around the Equator and the high rate
of weathering took so much CO2 out of the air that the global climate
flipped to "cold" and the oceans froze over. That stopped the oceanic
CO2 sink, and the climate flipped to "warm" when volcanic CO2 built up
enough to get enough greenhouse warming to melt it.

Happened several times, a planetary sized relaxation oscillator.

Mark Zenier [email protected]
Googleproofaddress(account:mzenier provider:eskimo domain:com)