Global Warming & Climate Change Discussion

[BiggieShady]

Give it up dude. It's a ridiculous argument for which you have no proof. Continue posting about it if you must but no is buying it and more importantly, no one cares.

The dude is saying that in that left&right image on the right side, where sahara is red - it would be yellow if it were covered in solar panels ... arguably based on difference in albedo of sahara sand and the panel

 

[twilyth]

The dude is saying that in that left&right image on the right side, where sahara is red - it would be yellow if it were covered in solar panels.

LOL. Yes. I think I can see that now.

 

[FordGT90Concept]

All your so-called "math" shows is that dark surfaces radiate heat. Woo-hoo

Up to ~325 W/m2 which is significant.

The dude is saying that in that left&right image on the right side, where sahara is red - it would be yellow if it were covered in solar panels ... arguably based on difference in albedo of sahara sand and the panel

Yes! Edit: Well, no. deserts have low albedo. Plant life is what increases albedo the most. Solar panels in deserts and on top of dark roofs are perfectly fine. It's everywhere else that's a problem.

LOL. Yes. I think I can see that now.

Finally!

 

[twilyth]

Sure, whatever you say.

 

[silkstone]

All your so-called "math" shows is that dark surfaces radiate heat. Woo-hoo

Also remember that solar PV offsets coal power. So you're really comparing the heat absorbed from the pv cells to the heat generated from burning coal. I'm pretty sure it's negligible.

When using solar for heating water vs. electricity or gas it really does make sense. Coal stands at about 31% average efficiency with solar at a guestimate of well over 80%

Every energy source turns into heat in the end. It's the efficiency at capture that is important when considering any kind of warming effect.
All the energy converted into electricity eventually gets converted into heat.

PV work on absorption of light, so direct comparisons are difficult. However, the overall heat output of all the power-stations (fossil fueled or note) is negligible when compared with the effect of the increased levels of greenhouse gasses.

 

[BiggieShady]

LOL. Yes. I think I can see that now.

arguably based on difference in albedo of sahara sand and the panel

I did edit my post with "arguably" section it seems to me that panels are made and are great for absorbing and sahara sand is great for reflecting ... or albedo of the sand is greater ... so one solar panel = huge leaf of a high-tech forest

 

[twilyth]

Also remember that solar PV is offsets coal power. So you're really comparing the heat absorbed from the pv cells to the heat generated from burning coal. I'm pretty sure it's negligible.

When using solar for heating water vs. electricity or gas it really does make sense. Coal stands at about 31% average efficiency with solar at a guestimate of well over 80%

Every energy source turns into heat in the end. It's the efficiency at capture that is important when considering any kind of warming effect.
PV work on absorption of light, so direct comparisons are difficult. However, the overall heat output of all the power-stations is negligible when compared with the effect of the increased levels of greenhouse gasses.

Don't waste you time. I've already made similar arguments but they don't seem to register with Ford.

The less CO2 there is in the atmosphere, the more infrared energy gets radiated into space. Since PV reduce the amount of CO2 pumped into the atmosphere they help to reduce the amount of infrared that gets trapped.

 

[FordGT90Concept]

Also remember that solar PV offsets coal power. So you're really comparing the heat absorbed from the pv cells to the heat generated from burning coal. I'm pretty sure it's negligible.

No, it doesn't. Coal takes 48 to 72 hours to start/stop. The primary fossil fuel solar and wind compete with is oil, gasoline, kerosene, propane, diesel, and natural gas. In short, everything you can set a match to and it burns vigorously. These are known as peak power plants because they can be turned on and off with little side effect and they take very little time (some as low as 3 minutes) to reach maximum output.

I did edit my post with "arguably" section it seems to me that panels are made and are great for absorbing and sahara sand is great for reflecting ... or albedo of the sand is greater ... so one solar panel = huge leaf of a high-tech forest

Backwards. The green on the left side is good. The red on the right side is bad. The Sahara is very hot compared to the forests of the Amazon and Africa. Because of this, deserts are fantastic for solar not just because the sky is usually clear and the property values are low, the albedo of the sand is really low (it absorbs the heat and the lack dry air provides little distortion to the rays) and most solar panel technologies are higher.

 

[silkstone]

Don't waste you time. I've already made similar arguments but they don't seem to register with Ford.

The less CO2 there is in the atmosphere, the more infrared energy gets radiated into space. Since PV reduce the amount of CO2 pumped into the atmosphere they help to reduce the amount of infrared that gets trapped.

I guess we should cut down all the trees on the planet too. They are too damn good at absorbing the sunlight!

No, it doesn't. Coal takes 48 to 72 hours to start/stop. The primary fossil fuel solar and wind compete with is oil, gasoline, kerosene, propane, diesel, and natural gas. In short, everything you can set a match to and it burns vigorously. These are known as peak power plants because they can be turned on and off with little side effect and they take very little time (some as low as 3 minutes) to reach maximum output.

Yes, but if it they are set up in conjunction with another source. That's 1 less coal plant you need to build.

Edit - there are better sources than solar. The nuclear reactors that feed on nuclear waste and spit out low-half-life waste seem to be the way forward, but for the politicians blocking the technology (molten salt reactors and another which I forget the name of)

 

[FordGT90Concept]

I guess we should cut down all the trees on the planet too. They are too damn good at absorbing the sunlight!

Noooo, they absorb UV but reflect a lot of visible and thermal energy. That's why on a bright sunny day, plants often still feel cool (relatively anyway) to the touch. UV radiation in sunlight is actually pretty weak compared to visible and thermal.

Edit: Linkage There was a better one than this with more exact figures but I lost it.
50% thermal
40% visible
10% ultraviolet

Yes, but if it they are set up in conjunction with another source. That's 1 less coal plant you need to build.

If you mean solar + natural gas, yes, but that trend was forming regardless due to economic factors. Obama/EPA has put in place what is effectively a cap and trade system which weighs heavily against coal in addition to natural gas price coming way down and supply going way up. Coal's outlook was decent looking coming in to the 21st century (because it is still abundant and cheap) but now, coal is pretty much dead last.

 

[newconroer]

It doesn't matter. Seriously, people can whine and moan about it one way or the other and it accomplishes absolutely nothing. Anything done by political leaders on the subject tends to be financial or political in nature. Again, nothing accomplished. Until we're either all burning to a crisp or freezing our butts off, nothing substancial will be done about it.

I'll just sit over here and wait for nature to rain down the apocalypse.

You might be sadly quite right that either way, it's all inevitable. However the problem is when it leaves the hands of the politicians and falls into the hands of individuals, vigilante groups and all out liberal whackos. Because like this 'animal rights' movement, it's one more thing shoved down our throats daily - to the point where we have to live in a society pushed to the edge by one more paranoia.

I shouldn't have to sit by the window at a restaurant in London, so I can watch my SUV and ensure it doesn't get keyed, slashed or blown up by ignorant mis-informed Facebook youth, or some eco-terrorist.


So if you're correct and it doesn't matter, then we need to teach that to people so they'll stop making it miserable for every one else, to listen to them moan about how we're raping the planet.
RAPE RAPE RAPE I say! It's OUR planet to do with as we see fit - whether you believe in God putting humans here, or not, we dominate and run the planet. I don't give a sh*t what happens in two thousands years, we live in the now.

 

[twilyth]

Noooo, they absorb UV but reflect a lot of visible and thermal energy. That's why on a bright sunny day, plants often still feel cool (relatively anyway) to the touch. UV radiation in sunlight is actually pretty weak compared to visible and thermal.

Wow. You really do just make this shit up as you go along don't you? I've got one word for you, please look it up - transpiration - http://en.wikipedia.org/wiki/Transpiration

 

[FordGT90Concept]

That too. Clouds tend to form over massive forests as well (perhaps as a function of transpiration) which have a really high albedo.

 

[DinaAngel]

The more trees we cut down in Brazil and Africa then the less co2 will be turned into oxygen. But these days trees and plants rot because of insects and bacteria and so the co2 goes up into atmosphere when they rot. Before this bacteria existed then we had peak of oxygen on earth.

But there's more cars on earth than its people, and if u visit China capital u will notice the thick foul car smoke covering whole city. They can't even see the sun at times.

Also the more Greenland ice melts the more sea levels rise and the more pressure on vulcanos since theyr like pimples they will burst. And example Yellowstone has enough ash to cover 90% of earth atmosphere. And those works like mirrors. It's happened before and this is why it's deadly to breathe it it's glass shards. And it would mean constant night for months probably 160 minus degrees Celsius

Some places on Greenland the ice is 4km thick so its a lot of water.
also the sea current that goes down at south Greenland it's saltwater. And Greenland is freshwater. And freshwater is lighter than saltwater so current will stop eventually.

Also the amount that melts per day is so much atm that we will see water levels rise a lot. all of Greenland contains enough freshwater to make sea levels like 25 meters globally

If u calculate how much co2 a car made in 90s and then find out how much 7 billion of them puts out in one day. It's enough to cover all of America with a deadly layer. I believe 60% co2 is deadly in the air

Try calculate it yourself

 

[rruff]

Yes...my point is, of all energy sources, solar is just about the least dense because it is a function of surface area. They contribute to atmospheric warming through production as well as absorption (as opposed to reflection) of solar energy; thusly, the environmental impact is linear. About the only place where the absorption is neutralized is on asphalt roof tops with a clear view of the sun because the asphalt has the same effect. Building the solar panel itself can only be mitigated, not eliminated, through industrial and mining processes.

Starting to think you are just making stuff up. For one I already showed you that only a tiny fraction of earth's surface area would be needed. This is from Sandia Labs: http://www.sandia.gov/~jytsao/Solar FAQs.pdf

"Sunlight has by far the greatest theoretical potential of all earth's renewable energy sources... there is more solar energy striking the earth's surface in 90 minutes than the world wide energy consumption from all sources in one year."

Or here: http://landartgenerator.org/blagi/archives/127

About 0.2% of the earth surface in solar PV could supply the projected total world energy consumption in 2030. Or maybe a figure that is easier to grasp, the same surface area that is currently covered by pavement in the US would be enough to supply all US energy.

Desert surfaces are not that reflective anyway. The albedo (reflectivity) of sand and dry dirt is in the .15-.45 range. That means it already absorbs more than it reflects. The albedo of a typical solar panel is ~.20. It's hardly any different. Plus it's converting 15-20% of the incident radiation into electricity rather than heat. So the amount of incident solar energy that would heat the air is on average less, not more than if the panel wasn't there.

 

[twilyth]

Starting to think you are just making stuff up. For one I already showed you that only a tiny fraction of earth's surface area would be needed. This is from Sandia Labs: http://www.sandia.gov/~jytsao/Solar FAQs.pdf

"Sunlight has by far the greatest theoretical potential of all earth's renewable energy sources... there is more solar energy striking the earth's surface in 90 minutes than the world wide energy consumption from all sources in one year."

Or here: http://landartgenerator.org/blagi/archives/127

About 0.2% of the earth surface in solar PV could supply the projected total world energy consumption in 2030.

Desert surfaces are not that reflective anyway. The albedo (reflectivity) of sand and dry dirt is in the .15-.45 range. That means it already absorbs more than it reflects. The albedo of a typical solar panel is ~.20. It's hardly any different. Plus it's converting 15-20% of the incident radiation into electricity rather than heat. So the amount of incident solar energy that would heat the air is on average less, not more than if the panel wasn't there.

Thanks for showing up Ford's bullshit. I think he relies on the fact that no one will be willing to make the effort to fact check him. He certainly doesn't fact check himself.

 

[xfia]

there is a solar roadway project.. pretty awesome stuff with led lights and room for all the cables you want. I cant remember the figure but what they said was a pretty small fraction of roadways being redone could supply more than enough power in the usa.

http://www.solarroadways.com/intro.shtml the videos will probably make you a supporter

 

[FordGT90Concept]

Starting to think you are just making stuff up. For one I already showed you that only a tiny fraction of earth's surface area would be needed. This is from Sandia Labs: http://www.sandia.gov/~jytsao/Solar FAQs.pdf

"Sunlight has by far the greatest theoretical potential of all earth's renewable energy sources... there is more solar energy striking the earth's surface in 90 minutes than the world wide energy consumption from all sources in one year."

1) You can't cover the whole planet (ecological disaster). You can't even cover large swaths of it for the same reason.
2) Most of the solar energy hits the oceans. That energy is crucial to keeping the Earth a relatively stable temperature. Interrupting it is very unwise.
3) Human population and energy needs are expected to continue to rise. Humans need three things: space, food, and energy. Solar energy sacrifices the first two in the name of the third. This is a lot like ethanol to me. Corn for energy or corn for food? Most sensible people should choose food for numerous reasons; solar radiation is a huge component of food production. There's only specific locations where solar energy makes sense. Anywhere solar energy competes with food, we need to choose food. You can't build them in forests. Mountain tops usually have huge construction/maintenance impediments on top of lack of demand. I could go on. I'm not going to do the math but what is absolutely certain is that there is a point, even if it were completely free, the cons will exceed the pros. It may not be at 2030, it may not be at 2100, but it is there and it is sooner than anyone would like it to be.

Desert surfaces are not that reflective anyway. The albedo (reflectivity) of sand and dry dirt is in the .15-.45 range.

30% is the global average. In other words, that's average.

That means it already absorbs more than it reflects. The albedo of a typical solar panel is ~.20. It's hardly any different. Plus it's converting 15-20% of the incident radiation into electricity rather than heat. So the amount of incident solar energy that would heat the air is on average less, not more than if the panel wasn't there.

The only solid albedo number I saw so far is from that Oregon link which said 30%. Those panels should be fine in a desert but the desert surface should be checked for albedo first. If it has particularly high albedo (e.g. your link's 45% number), it really shouldn't be built there. If you leave the albedo of 45% alone and build where it is 15% increasing it to 30% through the reflectivity of the panels, it effectively cools the planet a tiny bit which is a win in my book. This is especially true in deserts where there's little to no humidity.

there is a solar roadway project.. pretty awesome stuff with led lights and room for all the cables you want. I cant remember the figure but what they said was a pretty small fraction of roadways being redone could supply more than enough power in the usa.

http://www.solarroadways.com/intro.shtml the videos will probably make you a supporter

See thread: http://www.techpowerup.com/forums/threads/solar-roadways.202415/

It fails the basic math test in virtually every department (monetary cost, electrical cost, electrical generation, and so on).

 

[rruff]

there is a solar roadway project..

It's total nonsense. A road surface is about the worst possible place to put solar panels.

 

[W1zzard]

i wanted to do the math, but then i found that link:

http://www.treehugger.com/clean-tec...ls-actually-contribute-to-climate-change.html

some good thoughts on albedo of solar cells

 

[xfia]

It's total nonsense. A road surface is about the worst possible place to put solar panels.

I guess you skipped the videos.. haha really think it would be that bad?

 

[twilyth]

1) You can't cover the whole planet (ecological disaster). You can't even cover large swaths of it for the same reason.
2) Most of the solar energy hits the oceans. That energy is crucial to keeping the Earth a relatively stable temperature. Interrupting it is very unwise.
3) Human population and energy needs are expected to continue to rise. Humans need three things: space, food, and energy. Solar energy sacrifices the first two in the name of the third. This is a lot like ethanol to me. Corn for energy or corn for food? Most sensible people should choose food for numerous reasons; solar radiation is a huge component of food production. There's only specific locations where solar energy makes sense. Anywhere solar energy competes with food, we need to choose food. You can't build them in forests. Mountain tops usually have huge construction/maintenance impediments on top of lack of demand. I could go on. I'm not going to do the math but what is absolutely certain is that there is a point, even if it were completely free, the cons will exceed the pros. It may not be at 2030, it may not be at 2100, but it is there and it is sooner than anyone would like it to be.


30% is the global average. In other words, that's average.


The only solid albedo number I saw so far is from that Oregon link which said 30%. Those panels should be fine in a desert but the desert surface should be checked for albedo first. If it has particularly high albedo (e.g. your link's 45% number), it really shouldn't be built there. If you leave the albedo of 45% alone and build where it is 15% increasing it to 30% through the reflectivity of the panels, it effectively cools the planet a tiny bit which is a win in my book. This is especially true in deserts where there's little to no humidity.



See thread: http://www.techpowerup.com/forums/threads/solar-roadways.202415/

It fails the basic math test in virtually every department (monetary cost, electrical cost, electrical generation, and so on).

@rruff - see what I mean?

 

[rruff]

Humans need three things: space, food, and energy. Solar energy sacrifices the first two in the name of the third. This is a lot like ethanol to me. Corn for energy or corn for food?

You really went off the rails! Space? We have orders of magnitude more worthless desert than would be needed. If you don't like that, they can be put them on roofs. Food? Have no idea what you are thinking there. Solar PV would not be put on arable land and would not effect food production in the slightest.

The only solid albedo number I saw so far is from that Oregon link which said 30%. Those panels should be fine in a desert but the desert surface should be checked for albedo first. If it has particularly high albedo (e.g. your link's 45% number), it really shouldn't be built there. If you leave the albedo of 45% alone and build where it is 15% increasing it to 30% through the reflectivity of the panels, it effectively cools the planet a tiny bit which is a win in my book. This is especially true in deserts where there's little to no humidity.

You seem to be ignoring the fact that 15-20% of the incident radiation on a panel is converted to electricity rather than heat.

But lets say we go crazy and put up enough panels to supply 100% of the world's energy by 2030. Those panels would cover ~0.2% of the earth's surface. Now let's pretend they actually *do* heat the air more than if they didn't exist, by 10% of the solar energy hitting them. The earth currently absorbs ~70% of the solar energy that hits it, so this would represent .002x.1/.7= .0003 factor increase in energy absorbed. 1 in 3500. Care to guess how much that would increase the earth's temperature? It would be a complicated calculation to do properly, but you don't need to bother to know that it is infinitesimally small.

The sun's output already varies by >3x that amount over the course of a decade, and we see no appreciable effect from it on temperature.

 

[rruff]

I guess you skipped the videos.. haha really think it would be that bad?

I saw them when they came out. Made me really sad that so many people sent them money and they got so much press. It is a really, really stupid idea.

Here is a video that addresses some of the problems:

 

[xfia]

seems like a bunch of fud to me to worry about anything but how much sun panels will get.. doesn't really matter where you put a coal plant since it just pollutes. a few of the things in that video came to mind for me but lets be real about it.. that guy just insults everyone's intelligence with several easy argued points and doesn't even really make a complete point. obviously your not going to make every damn road solar and put all of your eggs in one basket. maybe just a little to innovative for some humans to see the possibilities.. hard to get most humans to even take out the trash on garbage day and use the recycle bin let alone stop using shitty asphalt when there is more reliable and cost effective options.