Global earth warming up

[Aimless]

Did you know that the amount of CO2 produced during the manufacture of modern solar panels is greater that the amount that will be saved by the energy production of that panel over the panel's lifetime?

LINK?

Ack. This is turning into a more difficult question than I thought it would be, and I may be wrong, since I can't seem to find much in the way of statistics on current solar cell manufacture. I know it used to be the case, but solar cells have gotten more efficient, as has the industry.

Here's what I can find : depending on manufacturer, final cost for solar power runs about $5/Watt. Solar cells have a general life expectancy of about 5 years, and at best about 1/4th of that time is spent generating electricity at peak capacity. Call it 1/3rd to account for non-peak production as well.

This gives a total end user cost of around 34 cents per kilowatt hour over the lifetime of the solar cell. Compared with a total end user cost of around 10 cents per kilowatt hour for traditional power.

Unfortunately, here my numbers break down, and I can't verify the statistic I originally posed. The question is what is the production cost of a solar cell (as opposed to the end user cost), and what that production cost breaks down into. It used to be the case that the energy consumption during the manufacture process was on the order of the total lifetime output of the solar cell, but since I can't verify that that is true anymore, I'll retract my claim.

So, my apologies to unriggable. I jumped the gun on the solar power thing. Solar power is still horribly inefficient, but I can't prove that solar power isn't green.

[flashleg8]

Did you know that the amount of CO2 produced during the manufacture of modern solar panels is greater that the amount that will be saved by the energy production of that panel over the panel's lifetime?

LINK?

Ack. This is turning into a more difficult question than I thought it would be, and I may be wrong, since I can't seem to find much in the way of statistics on current solar cell manufacture. I know it used to be the case, but solar cells have gotten more efficient, as has the industry.

Here's what I can find : depending on manufacturer, final cost for solar power runs about $5/Watt. Solar cells have a general life expectancy of about 5 years, and at best about 1/4th of that time is spent generating electricity at peak capacity. Call it 1/3rd to account for non-peak production as well.

This gives a total end user cost of around 34 cents per kilowatt hour over the lifetime of the solar cell. Compared with a total end user cost of around 10 cents per kilowatt hour for traditional power.

Unfortunately, here my numbers break down, and I can't verify the statistic I originally posed. The question is what is the production cost of a solar cell (as opposed to the end user cost), and what that production cost breaks down into. It used to be the case that the energy consumption during the manufacture process was on the order of the total lifetime output of the solar cell, but since I can't verify that that is true anymore, I'll retract my claim.

So, my apologies to unriggable. I jumped the gun on the solar power thing. Solar power is still horribly inefficient, but I can't prove that solar power isn't green.

Shock horror! An honest man on the internet? Someone who admits to a mistake - this can't be conquerclub, I must have logged in somewhere else by mistake

P.S. With respect to your original point, I'm not sure of the exact statistics of the CO2 used to manufacture solar cells either and I doubt that the energy used to create the solar cell is equal to the lifetime output - but you are completely correct to point out that energy is used to manufacture renewable energy devices, this initial energy input is often ignored when environmentalist state the savings created by using renewables. These "start up costs" should of course be factored in when calculating the benefits (economic and environmental) of using alternative power sources. Equally the lifetime energy costs associated with traditional power creating sources should be calculated properly. Costs of environmental clean up and waste disposal are routinely not counted when comparing renewables to nuclear power or hydrocarbon generation methods. When these hidden costs are factored in - even the high start up cost of renewables is offset and these sources become much more economically viable.

[foolish_yeti]

Ethanol.

Pretty stupid, but apparently hydrogen is not nearly as explosive as it is made out to be. So hydrogen powered cars would not be as dangerous as they are said to be. (some of you guys might say "hey, unriggable, remember the hindenburg?" but the more flammable part of that flying blob of shit was the coating and the paint used. So cars could be pretty safe if they ran on oxygen and hydrogen.

Problem with Ethanol is to replace oil on a massive scale you have to grow more crops....assuming you could even find enough farmland for agriculture above and beyond food, they'd most likely be massive monocultures.

The big negative against hydrogen right now is you have to find a way to collect/produce it on a large scale in a fashion that won't take mass amounts of energy.

This will also require a huge revamping and new construction for infrastructure. I'm not blindly ruling these options out, but there are some major problems with them that need to be thought through.

Solar cells have a general life expectancy of about 5 years

Depends on the cells- I've seen stats anywhere from 3-30+ years. There are systems on the market that have 25 year production warranty. I'd say a "general" life expenctancy would be more around 20+ years. Efficiency and durability are gettin' better.

[Neutrino]

The big negative against hydrogen right now is you have to find a way to collect/produce it on a large scale in a fashion that won't take mass amounts of energy.

Ironicaly, the most efficient way to produce Hydrogen at the moment is during the extraction of Coal.

[vtmarik]

Ethanol.

Pretty stupid, but apparently hydrogen is not nearly as explosive as it is made out to be. So hydrogen powered cars would not be as dangerous as they are said to be. (some of you guys might say "hey, unriggable, remember the hindenburg?" but the more flammable part of that flying blob of shit was the coating and the paint used. So cars could be pretty safe if they ran on oxygen and hydrogen.

Problem with Ethanol is to replace oil on a massive scale you have to grow more crops....assuming you could even find enough farmland for agriculture above and beyond food, they'd most likely be massive monocultures.

The big negative against hydrogen right now is you have to find a way to collect/produce it on a large scale in a fashion that won't take mass amounts of energy.

This will also require a huge revamping and new construction for infrastructure. I'm not blindly ruling these options out, but there are some major problems with them that need to be thought through.

I once heard that if the entire state of Iowa was re-purposed to grow soybeans, we could feed the world. The question then becomes, can we make ethanol from soybeans?

[Aimless]

Solar cells have a general life expectancy of about 5 years

Depends on the cells- I've seen stats anywhere from 3-30+ years. There are systems on the market that have 25 year production warranty. I'd say a "general" life expenctancy would be more around 20+ years. Efficiency and durability are gettin' better.

It depends on the conditions of use. Solar cells tend to wear poorly, and their output tends to degrade over time.

Then again, as mentioned before, my initial point was based on old statistics, and solar technology has improved remarkably in the last five years or so. It's still not up to snuff as regards other power generation sources, but it is starting to come close to the viability threshold. I wish I had current statistics to work with, so I could say something definitive on the subject; I'm disappointed that I couldn't back up one of my opinions.

P.S. With respect to your original point, I'm not sure of the exact statistics of the CO2 used to manufacture solar cells either and I doubt that the energy used to create the solar cell is equal to the lifetime output - but you are completely correct to point out that energy is used to manufacture renewable energy devices, this initial energy input is often ignored when environmentalist state the savings created by using renewables. These "start up costs" should of course be factored in when calculating the benefits (economic and environmental) of using alternative power sources. Equally the lifetime energy costs associated with traditional power creating sources should be calculated properly. Costs of environmental clean up and waste disposal are routinely not counted when comparing renewables to nuclear power or hydrocarbon generation methods. When these hidden costs are factored in - even the high start up cost of renewables is offset and these sources become much more economically viable.

Well, as of about a decade ago, given the fast degradation times of solar cells, the expected lifetime output of a given panel was only in the neighborhood of a thousand kilowatt hours or so (depending on the size of the panel, of course). So, it's reasonable to expect that the production costs overwhelmed the benefits of producing the cells in the first place.

As far as the costs of environmental cleanup and waste disposal, you are absolutely correct, at least as regards coal and oil plants. Nuclear plants are a different story, since a sane approach to dealing with the waste would actually be quite cheap, and require very little in terms of long term storage. (By "sane," I mean making used of fast breeder reactor technology and reprocessing of spent fuel to limit the amount of waste that actually has to be disposed of to only the unusable byproducts and lighter isotopes left over from the fission process. This waste actually only accounts for about 1% of the spent fuel, and can be easily stored for the 400 or so years required without the need to hollow out a mountain in Nevada to dump it under.)

[vtmarik]

As far as the costs of environmental cleanup and waste disposal, you are absolutely correct, at least as regards coal and oil plants. Nuclear plants are a different story, since a sane approach to dealing with the waste would actually be quite cheap, and require very little in terms of long term storage. (By "sane," I mean making used of fast breeder reactor technology and reprocessing of spent fuel to limit the amount of waste that actually has to be disposed of to only the unusable byproducts and lighter isotopes left over from the fission process. This waste actually only accounts for about 1% of the spent fuel, and can be easily stored for the 400 or so years required without the need to hollow out a mountain in Nevada to dump it under.)

Breeder reactors are a waste of time and energy. Integral Fast Reactors (IFRs, which are related to ALMRs) can use any Actinide as fuel and get over 90% efficiency. Who needs a breeder reactor paired with a traditional reactor when you could built an IFR and get double the work done with half the cost?

[foolish_yeti]

I once heard that if the entire state of Iowa was re-purposed to grow soybeans, we could feed the world. The question then becomes, can we make ethanol from soybeans?

The majority of ethanol production is corn, but there's other sources...never heard of any made from beans. Might be possible, but maybe not the best choice.

Then there's the issue of turning an entire state into a monoculture, which I don't think is such a hot idea. They've allowed us to increase food production but I think pose too many problems (one of them being an increase in food production- tee hee).

[Aimless]

Hmmm. I'm not familiar with IFR's.

My information regarding breeder reactors comes from a seminar I recently attended given by a nuclear engineer, whose claim was that the preferred way to go was a liquid metal fast breeder reactor, since it can serve as a fuel source for the existing light water reactors and can burn the Actinide isotopes left over from them.

Well, at any rate, the point stands : with a sane implementation of nuclear technology, nuclear waste is not a problem.

[vtmarik]

Hmmm. I'm not familiar with IFR's.

My information regarding breeder reactors comes from a seminar I recently attended given by a nuclear engineer, whose claim was that the preferred way to go was a liquid metal fast breeder reactor, since it can serve as a fuel source for the existing light water reactors and can burn the Actinide isotopes left over from them.

Well, at any rate, the point stands : with a sane implementation of nuclear technology, nuclear waste is not a problem.

Agreed, I believe it was Eisenhower who signed the bill outlawing the recycling of nuclear waste into useable fuel. What a moron.

I did a paper on IFRs for an english class, they're absolutely fascinating.

[unriggable]

Apparently there are variations of solar power - the older ones use a series of mirrors that are angled to bounce the sun's light to a salt pillar, which heats up, and the heat is transfered to a tub of water, boiling it. From this they have enough electricity to power 10,000 homes. In theory, these can last forever, assuming maintenance continues to keep it aht way. So they really do not have an expiration rate. The newer ones, which absorb the light, expire, but with time this technology will only improve.

[Hologram]

I once heard that if the entire state of Iowa was re-purposed to grow soybeans, we could feed the world. The question then becomes, can we make ethanol from soybeans?

The majority of ethanol production is corn, but there's other sources...never heard of any made from beans. Might be possible, but maybe not the best choice.

Then there's the issue of turning an entire state into a monoculture, which I don't think is such a hot idea. They've allowed us to increase food production but I think pose too many problems (one of them being an increase in food production- tee hee).

I believe at the Oregon State University School of Agriculture they're trying to produce a grass/weed/whatever you want to call it that grows in abundance and produces large amounts of ethanol.

[flashleg8]

As far as the costs of environmental cleanup and waste disposal, you are absolutely correct, at least as regards coal and oil plants. Nuclear plants are a different story, since a sane approach to dealing with the waste would actually be quite cheap, and require very little in terms of long term storage. (By "sane," I mean making used of fast breeder reactor technology and reprocessing of spent fuel to limit the amount of waste that actually has to be disposed of to only the unusable byproducts and lighter isotopes left over from the fission process. This waste actually only accounts for about 1% of the spent fuel, and can be easily stored for the 400 or so years required without the need to hollow out a mountain in Nevada to dump it under.)

I don't necessarily disagree with your point of view here - I am generally pro-nuclear power - I'm just questioning the emboldened statement.
In my original post I was highlighting the need to account for the total costs associated with an energy source (including waste disposal - as you have replied to). You state "[nuclear waste] can be easily stored for the 400 years required". The cost of long-term storage must be high - 400 years of regular tracking of the stability and security of the waste cannot come cheap. Also how is it possible to guarantee that this waste will be secure for this length of time. It is highly likely that the country involved will go through massive political and economic upheaval in this time frame - it only takes one lapse for this waste to cause an environmental disaster. The time frame involved for some wastes may even be affected by geological effects!
Hardly "easy" storage.
I actually think it is quite negligent to create energy in this way and leave a massive legacy for future generations. Any expansion in the use of nuclear energy must be offset with provisions for the future treatment of the waste. By this I mean financially (perhaps creating trust funds for future generations that might not be as energy rich and economically affluent) but we also have a responsibility to minimise our need for the creation of the energy in the first place. We must be more efficient (creating less waste) and wise (stop using energy on frivolous luxuries) in our energy consumption.
I understand your argument for the modern minimisation of nuclear waste - but when fossil fuels run out we will likely have to massively increase our reliance on nuclear fuel, increasing the potential waste by orders of magnitude.

[flashleg8]

I believe at the Oregon State University School of Agriculture they're trying to produce a grass/weed/whatever you want to call it that grows in abundance and produces large amounts of ethanol.

Once they figure out how to get weed that produces alcohol those students are on to a winner!

[alex_white101]

I believe at the Oregon State University School of Agriculture they're trying to produce a grass/weed/whatever you want to call it that grows in abundance and produces large amounts of ethanol.

Once they figure out how to get weed that produces alcohol those students are on to a winner!

i think, no matter the truth in your statement, it may be a little off topic.......

[feiterman]

Something I actually know quite well. So ill try to answer some of the questions that i have seen on the last page of posts. Other sources of ethanol besides corn include moss type planets, like hearty small woody plants if that makes any sense. Just a couple of quick facts that i found quite intersting when i did a report on this topic, 95% of Brazil's auotmobils run on a ethanol gas mix, which cut their oil consumption by 50%, and Austrilla( for anyone who lives there) has enough uranium to power the whole country for the next 75 years. If any of you guys are really interested in this topic there is a great book out there called the Weather makers by Tim Flannery.

[Aimless]

n my original post I was highlighting the need to account for the total costs associated with an energy source (including waste disposal - as you have replied to). You state "[nuclear waste] can be easily stored for the 400 years required". The cost of long-term storage must be high - 400 years of regular tracking of the stability and security of the waste cannot come cheap. Also how is it possible to guarantee that this waste will be secure for this length of time. It is highly likely that the country involved will go through massive political and economic upheaval in this time frame - it only takes one lapse for this waste to cause an environmental disaster. The time frame involved for some wastes may even be affected by geological effects!

99% of all "nuclear waste" as it is currently tabulated is not actually waste. It is merely spent fuel, and can be reprocessed and put back into the reactor.

The remaining 1% consists of certain Actinide isotopes produced when U-238 absorbs neutrons that cannot be burned in a traditional light water reactor but can be burned in a newer reactor design, as well as the true fission waste products, which are generally hot isotopes of elements such as Cesium, Strontium, etc. Basically, anything out of the middle of the periodic table.

However, the amount of true waste produced is really miniscule. Small enough that, using only existing storage capacity, we will never run out of space at the current rate of production. Further, contrary to popular opinion, that waste isn't particularly dangerous. Oh, it's toxic enough that it would be a bad idea to dump it in a river, but all that's really required is to seal it in a leak-proof container and drop it into a pool of water. (The water, by the way, acts only as a heat exchanger to prevent the waste from heating up and melting its container. Shielding is unimportant; virtually all of the waste decays by beta emission, which can be stopped by about an inch of metal.)

As the waste could be used to build a dirty bomb, there's potentially a security risk, but no more so than with any other toxic substance. (And, frankly, dirty bombs are really dumb. They work only as a scare tactic, and only because of the irrational fear of nuclear waste that pervades our society. In terms of actual damage, even the crude chlorine gas bombs the terrorists have detonated in Iraq recently are more effective.)

As for causing an environmental disaster, you have bought into the decades of hype regarding nuclear waste. We couldn't cause an environmental disaster with the stuff if we tried - at least, not one of the magnitude you seem to be implying. Like I said, it's really no more dangerous than any other toxic chemical; frankly, there are worse spills every year from failed containment at chemical plants than anything likely to result from mishandling of nuclear waste.