Green Peace Leader Rags on Solar Power

[LMagic007]

Originally Posted by Wobs

So you hear optomism in an industry and you don't question it? What if the fossil fuel industry were optomistic that they could build power stations that would use fuel that wouldn't harm the environment? Would you accept it so blindly? You would rightly question it I'm sure.

If you only want other industries to criticise solar thermal, then you might have a long wait. Is the criticisms of the nuclear industry only from wind or solar manufacturers? Or do you also listen to pressure groups and other sources.

Or would you prefer it that we all question all power generation industries?

Personally I prefer the latter. As long as its based upon some kind of truth of course. When I question the viability of solar thermal, its based upon experience of looking at other power generation technologies, and some basic egineering and environmental issues. I don't pretend to have all the answers, but at the same time, it would be appreciated if you didn't get so defensive about it, as it is highly detrimental to the discussion of such technology. Any issue I've raised about it you've either said is a "mute point" - even though you've never brought it up; "it's obvious"; or "irrelevant". There is no need for such defensive behaviour if you want a constructive discussion, and none of those responses are helpful and often most inappropriate. How can a comment not previousely mentioned that is relevant be a mute point?

I may have had a cryptic question to begin with, but that does not warrant such responses. You always seem to avoid answering questions I ask, no matter how relevant to the issue in hand.

You can express whatever opinion you want. That's fine by me, but expect others to have the same privellige. My time is too valuable to spend addressing every single micro point you raise. In light of all your points raised thus far, my conclusion remains that Solar Thermals positives far outweigh its negatives. I'm happy to leave it at that and let others have their say if they so choose.

As I said though, instead of hearing from you all the time, seeing and hearing something reflected by industry from your side of the discussion, would at this juncture be far more entertaining. If you can get some external information, you are most welcome to post it. If only to bring less monotony to the discussion. I will be eagerly awaiting anything you can find.

[LMagic007]

Originally Posted by Wobs

I can see where you're coming from here (re nuclear), but then when you are faced with people who are so dead against something you are in favour of, one is hardly going to come out with limitations to it to reinforce their position, as one rarely even gets the opportunity, and nearly all the objections that people put up against nuclear are flawed IMHO. I've stated many times in this thread alone that I'm in favour of this technology, but its the limits of its application that I wanted to discuss. To just celebrate it is a bit blind to me.

Do you see how the two issues are different? (No pun intended)


While you may be right overall in that statement, we must not lose sight of the fact that every techology has its limits. To do so would be to do us all a disservice. To object to discussing its limitations doesn't sit well with me.


You do yourself no favours here.

You are just repeating what I have already said. As I previously stated, all technologies have limits. That's a given and accepted. If you wish to see others as blind, so be it. I personally don't have time for that. As I said, before, you have raised your negative points about Solar Thermal. I don't have to agree with you and I don't happen to agree with you. As indicated, with all the negatives, my overall view of Solar Thermal's potential is overwhelmingly positive and this is reflected in my representations of this technology.

People are free to form their own views. I won't say much about nuclear because I don't know a huge amount about it and I don't have a great deal of interest in it. I will however say that nuclear energy also has its limits of application. The parameters of discussion are common the technologies are different. That also is a given. I'm interested in Solar and Wind energy, so naturally I will tend to discuss these topics in their respective forums. Some people are interested in other topics.

Also contrary to your representation, I don't object to discussing limitations of any technology. I have discussed many issues relating to your perception of limitations to Solar Thermal, however this type of discussion can go on forever and I don't have time for that. Others are welcome to carry the baton for either or both views, but I have indicated my overall position on Solar Thermal energy and I don't need to elaborate any further. I'm not going to continually debate every single point you raise. Others are welcome to jump in. I have expressed my overall position.

I'm not aware of anyone in this forum, who is the sole authority on this topic. Thus the more separate views the better. People can make up their own minds as well they should.

[Karl]

Originally Posted by forfismum

It generates steam to drive the turbines which produce the power and then the steam condenses into water and is reheated and turned to steam and it drives the turbine and then it condenses into water and is reheated and turned to steam and it drive the turbines and condenses back into water.DO YOU GET THE PICTURE ??
Ooops sorry for being loud ,we have a new policy of being polite in the forum.

No, I was not referring to the steam generated by the reactor, used to drive the turbines. It was a reference to the water used for the nuclear power plant's cooling towers, ~70% of which directly evaporates. For example, nuclear power plants typically consume about 50 million gallons of water per day, 35 million of which evaporate.

[LMagic007]

Interestnig article here on water usage for a nuclear power station.

http://www.aph.gov.au/LIBRARY/Pubs/r...-07/07rn12.pdf

Which I think this guy Patrick Moore from Green Peace is now promoting isn't he ?

[Wobs]

Originally Posted by LMagic007

You are just repeating what I have already said. As I previously stated, all technologies have limits. That's a given and accepted. If you wish to see others as blind, so be it. I personally don't have time for that. As I said, before, you have raised your negative points about Solar Thermal. I don't have to agree with you and I don't happen to agree with you. As indicated, with all the negatives, my overall view of Solar Thermal's potential is overwhelmingly positive and this is reflected in my representations of this technology.

You have demonstrated beyond doubt, how incapable you are at discussing the limits of solar thermal (or indeed any technology you happen to like), no matter how clear they are. I tried to ask you what they were, and you ignored them, choosing to get tetchy instead, even though I don't object to the use of said technology.

People are free to form their own views. I won't say much about nuclear because I don't know a huge amount about it and I don't have a great deal of interest in it. I will however say that nuclear energy also has its limits of application. The parameters of discussion are common the technologies are different. That also is a given. I'm interested in Solar and Wind energy, so naturally I will tend to discuss these topics in their respective forums. Some people are interested in other topics.

It is the advantages and drawbacks of every technology that dictates their uses. Nuclear has its limits as well, but of course its opponents will only focus on those, which makes it tricky to discuss such things in a balanced way generally. I was hoping to have a balanced discussion with you on Solar Thermal, but you were extremely reluctant to do so.

Also contrary to your representation, I don't object to discussing limitations of any technology. I have discussed many issues relating to your perception of limitations to Solar Thermal, however this type of discussion can go on forever and I don't have time for that. Others are welcome to carry the baton for either or both views, but I have indicated my overall position on Solar Thermal energy and I don't need to elaborate any further. I'm not going to continually debate every single point you raise. Others are welcome to jump in. I have expressed my overall position.

I asked you what other limits there were, and you refused to answer. When I listed some, you accused me of stating the obvious, despite you not mentioning them when asked. You then wouldn't acknowledge how these would effect its application.

I'm not aware of anyone in this forum, who is the sole authority on this topic. Thus the more separate views the better. People can make up their own minds as well they should.

Indeed.

[LMagic007]

Originally Posted by Wobs

You have demonstrated beyond doubt, how incapable you are at discussing the limits of solar thermal (or indeed any technology you happen to like), no matter how clear they are. I tried to ask you what they were, and you ignored them, choosing to get tetchy instead, even though I don't object to the use of said technology.

I have demonstrated I don't have the time to waste responding to your repetitive nit picking questions, when I have indicated that overall with all the positives and negatives considered, I still believe Solar Thermal's positives by far outweigh its negatives.

Originally Posted by Wobs

It is the advantages and drawbacks of every technology that dictates their uses. Nuclear has its limits as well, but of course its opponents will only focus on those, which makes it tricky to discuss such things in a balanced way generally. I was hoping to have a balanced discussion with you on Solar Thermal, but you were extremely reluctant to do so.

You appear to generalize about nuclear in this way to excuse it from discussion. Not that I want to discuss it, as it does not interest me. Speak to someone who is interested. Arguments for any topic should be treated with the same level of scrutiny.

Originally Posted by Wobs

I asked you what other limits there were, and you refused to answer. When I listed some, you accused me of stating the obvious, despite you not mentioning them when asked. You then wouldn't acknowledge how these would effect its application.

Go discover the limits for yourself, if that makes you feel better. All technologies have limits. It's not my job to tell you about information which you are interested. That's your responsibility to find out for yourself to satisfy yourself. As indicated, I still believe Solar Thermal's positives by far outweigh its negatives. Move on. I have already explained myself. I and I suspect others don't have the time to go on wasting time discussing your every point. At the end of the day it still comes up with Solar Thermal being viewed far more positive than negative and that is the deciding factor.


Rather than whinging and whining, go find someone who has the time to answer your every question. I suspect after it all, they will come to the same conclusion, that despite the negatives you have raised, the positives of Solar Thermal will by far outweigh them. I also suspect that others like myself, would also be able to come to an overall view of Solar Thermal without ongoing assessment of every aspect of the technology.

I and I suspect others don't have the time to discuss each and every aspect of any technology, let alone Solar Thermal. The sensible person is able to weigh up the key factors, positive and negative and form a general perspective, and quickly move on to new more interesting discussions, or other important things in their daily lives. I have already outlined my perspective. Anything else is just a waste of time so far as this thread is concerned, unless it's a show stopper. It's evident their aint no show stoppers on the horizon, but if and when they were to emerge, they could then be discussed as appropriate.

[Wobs]

Sorry, I was under the impression that this was a forum where people were meant to discuss things such as solar technology.

[LMagic007]

Originally Posted by Wobs

Sorry, I was under the impression that this was a forum where people were meant to discuss things such as solar technology.

Indeed it is, and indeed we and others have. You are more than welcome to discuss the topic of solar technology as much as you like. Keep on discussing, whilst I divert my time to other important matters. You can be your own audience if you like. I have conveyed my overall view on Solar Thermal as well as discuss more specific points. The direction of any technology hinges on the overwhelming body of opinion, of advantages against disadvantages.

As I indicated, my overall view is that the contribution of Solar Thermal will be significant, despite any perceptions of shortcomings that you might have. There is no point that you have raised that would change this overwhelming perspective. Industry evidence overwhelmingly reinforces my view and I suspect industry has far better insight into Solar Thermal technology and its limits, than you, me and many others. Beyond such views, for me and I suspect others, might prefer to manage our time somewhat more productively, rather than waste it reiterating the same view.

[Wobs]

While I still like the idea of solar thermal, some interesting view points (opinions) from the link put up in the nuclear forum, talks briefly about solar thermal (http://www.motherjones.com/blue_marb...t-brand.html):

"You got me thinking about those solar generating parks...here are some figures I just pulled off the net.

How much land area is required for Solar vs. Nuclear?

Solar Photovotaic (PV)

SkyPower Corp and SunEdison Canada announced the groundbreaking of First Light, North America’s largest solar photovoltaic 19 megawatt (MW) solar park, located on 300 acres in Lennox & Addington County, Ontario.

300 acres / 20 MW = 15 acres per MW

Solar – Thermal
The proposed project includes three solar concentrating thermal power plants, based on distributed power tower and heliostat mirror technology, in which heliostat (mirror) fields focus solar energy on power tower receivers near the center of each heliostat array. The total area required for all three phases and 400 MW would including the administration building/operations and maintenance building and substation is 3,400-acres.

3400 acres / 400 MW = 8.5 acres per MW

Solar – Thermal
Total Generation –280 megawatts, 70 miles southwest of Phoenix, near Gila Bend, Arizona. Concentrating Solar Power (CSP) technology with thermal energy storage. Solana’s parabolic mirrors focus the sun’s heat on a heat transfer fluid. The fluid can reach a temperature of 735 degrees Fahrenheit. To produce electricity, the hot fluid transfers its heat energy to water, creating steam. The steam is then used to run conventional steam turbines. The heat energy in the fluid also can be stored and used at a later time to generate electricity. The Solana Generating Station will cover 3 square miles and contain 2,700 parabolic trough collectors. Located on what is currently agricultural land, the power plant will use 75 percent less water than the current use of the property.
3 square miles x 640 acres/ sq mile = 1920 acres. 1920 acres / 280 MW = 6.85 acres / MW
Nuclear
Two nuclear plants were evaluated for power density. One produces 2400 MW on 650 acres, resulting in 0.27 acres / MW. Another nuclear power plant 50 miles west of Phoenix, generates 4000 MW on 1000 acres or 0.25 acres / MW.

Now compare:

Solar – photovoltaic 15 acres / MW means 15,000 acres 1000 MW

Solar – thermal 7 acres / MW means 7,000 acres 1000 MW

To equal replace the Arizona nuclear power plant,

Solar – PV would need 60,000 acres, or 94 square miles, a 9.4 x 10 mile rectangle
Solar – Thermal would need 28,000 acres, or 44 square miles, a 7 x 6.3 mile rectangle

Manhattan Island = 23 square miles

20,000 MW, as you suggest…

Solar – PV would need 300,000 acres or 468 square miles

Solar – Thermal would need 140,000 acres, or 218 square miles

Rhode Island = 1045 square miles

The same nuclear island would be 5000 acres or 7.8 square miles.

Seems that for large scale generation, solar, in its current state, would require significant amounts of land. Now there is an environmental impact!"

And:


"Ausra's system concentrates solar energy on a tube, causing the water in the tube to boil at an elevated pressure. This is the same basic process that is going on in a nuclear reactor or a coal-fired power plant. That hot steam then goes to a steam turbine and is then condensed in a condenser. That condenser HAS to use air as the heat rejection medium instead of water, because air is the only cooling medium available out in the desert. Air is a lousy choice, but it's the only one they have.

Because they must employ air cooling, they have to run the condenser at a higher temperature than you would want, for improved efficiency, if you were near a body of water like a river or lake. The efficiency of the overall process takes a serious hit. You're not getting away with anything, thermodynamically.

You then say photovoltaics employ no water cooling. Again, true, but they wish they could. The conversion efficiency of a photovoltaic cell is inversely proportional to its operating temperature, a fact well known to those who work with the technology. If you have a 10% efficient PV cell, then 90% of the energy that strikes that cell must be rejected as waste heat. To convey that waste heat to the ambient medium (air) the cell will assume a equilibrium temperature that is sufficiently elevated to conduct this waste heat to the air. The higher this equilibrium temperature, the worse the performance of the PV cell. Systems that use concentrated sunlight on PV arrays must use active cooling (either with water or ammonia or some other coolant) to avoid degrading the PV cell performance so badly that the efficiency is completely shot.

Dealing with the problems of heat rejection is not only endemic to all heat engines, like nuclear and solar thermal, but is fundamentally a part of systems like photovoltaics, whether we like it or not."

[LMagic007]

The url you posted to another chat forum topic re; nuclear power land usage vs solar and wind appears to be a dead link.

Originally Posted by Wobs

http://www.motherjones.com/blue_marb...t-brand.html):

File Not Found
Looks like this page is out of date, or perhaps you mistyped a URL

I will let Ausra be the judge of its own performance benchmarks, though I would also be happy for their results to be audited, just as with any other power suppliers results. ( all in the context of CO2 abatement of course ) and of course your own figures.

In regard to your posted workings here, in terms of land usage alone, it appears you have not factored in land used in uranium exploration and mining, waste disposal and storage, processing of materials, manufacturing of plant and equipment and a host of other factors too long to spend time listing and researching. That speaks volumes about my confidence in the value of taking this discussion to the nth degree. I think that is reason enough, for people not to invest too much more time pondering the combinatorial possibilities associated with various power generation plant types and configurations on this thread.

Your posted figures on land use for nuclear power alone, do not seem to reflect figures I have seen from a range of sources on the net and sadly for the sake of credibility of your estimates are starting to appear less credible than dare I say it, Professor Google's. Even the US government figures suggest a range of 5 to 10 acres per MW for nuclear power which makes your 0.27 figure out by at least 18 fold and up to 36 fold out. Other sources suggest even more land is used for nuclear per MW capacity, in the range of 30 to 70 acres per MW for nuclear power all up.

I would rather defer to government and industry reports, of which there are many, because this is a prime example of what appears to be an overly simplistic, incomplete, erroneous and misleading assessment and unfortunately, I and I suspect others would not view these calculations you have made with great confidence. As mentioned, all technologies have limitations and yes some limitations are dictated by common laws of nature. Many technologies also have environmental impact in one form or another. Thus by all means work things over for your own piece of mind, but kindly excuse me and the hopefully enlightened crowd, whilst other pressing matters are attended to.

Originally Posted by Wobs

While I still like the idea of solar thermal, some interesting view points (opinions) from the link put up in the nuclear forum, talks briefly about solar thermal (http://www.motherjones.com/blue_marb...t-brand.html):

"You got me thinking about those solar generating parks...here are some figures I just pulled off the net.

How much land area is required for Solar vs. Nuclear?

Solar Photovotaic (PV)

SkyPower Corp and SunEdison Canada announced the groundbreaking of First Light, North America’s largest solar photovoltaic 19 megawatt (MW) solar park, located on 300 acres in Lennox & Addington County, Ontario.

300 acres / 20 MW = 15 acres per MW

Solar – Thermal
The proposed project includes three solar concentrating thermal power plants, based on distributed power tower and heliostat mirror technology, in which heliostat (mirror) fields focus solar energy on power tower receivers near the center of each heliostat array. The total area required for all three phases and 400 MW would including the administration building/operations and maintenance building and substation is 3,400-acres.

3400 acres / 400 MW = 8.5 acres per MW

Solar – Thermal
Total Generation –280 megawatts, 70 miles southwest of Phoenix, near Gila Bend, Arizona. Concentrating Solar Power (CSP) technology with thermal energy storage. Solana’s parabolic mirrors focus the sun’s heat on a heat transfer fluid. The fluid can reach a temperature of 735 degrees Fahrenheit. To produce electricity, the hot fluid transfers its heat energy to water, creating steam. The steam is then used to run conventional steam turbines. The heat energy in the fluid also can be stored and used at a later time to generate electricity. The Solana Generating Station will cover 3 square miles and contain 2,700 parabolic trough collectors. Located on what is currently agricultural land, the power plant will use 75 percent less water than the current use of the property.
3 square miles x 640 acres/ sq mile = 1920 acres. 1920 acres / 280 MW = 6.85 acres / MW
Nuclear
Two nuclear plants were evaluated for power density. One produces 2400 MW on 650 acres, resulting in 0.27 acres / MW. Another nuclear power plant 50 miles west of Phoenix, generates 4000 MW on 1000 acres or 0.25 acres / MW.

Now compare:

Solar – photovoltaic 15 acres / MW means 15,000 acres 1000 MW

Solar – thermal 7 acres / MW means 7,000 acres 1000 MW

To equal replace the Arizona nuclear power plant,

Solar – PV would need 60,000 acres, or 94 square miles, a 9.4 x 10 mile rectangle
Solar – Thermal would need 28,000 acres, or 44 square miles, a 7 x 6.3 mile rectangle

Manhattan Island = 23 square miles

20,000 MW, as you suggest…

Solar – PV would need 300,000 acres or 468 square miles

Solar – Thermal would need 140,000 acres, or 218 square miles

Rhode Island = 1045 square miles

The same nuclear island would be 5000 acres or 7.8 square miles.

Seems that for large scale generation, solar, in its current state, would require significant amounts of land. Now there is an environmental impact!"

And:


"Ausra's system concentrates solar energy on a tube, causing the water in the tube to boil at an elevated pressure. This is the same basic process that is going on in a nuclear reactor or a coal-fired power plant. That hot steam then goes to a steam turbine and is then condensed in a condenser. That condenser HAS to use air as the heat rejection medium instead of water, because air is the only cooling medium available out in the desert. Air is a lousy choice, but it's the only one they have.

Because they must employ air cooling, they have to run the condenser at a higher temperature than you would want, for improved efficiency, if you were near a body of water like a river or lake. The efficiency of the overall process takes a serious hit. You're not getting away with anything, thermodynamically.

You then say photovoltaics employ no water cooling. Again, true, but they wish they could. The conversion efficiency of a photovoltaic cell is inversely proportional to its operating temperature, a fact well known to those who work with the technology. If you have a 10% efficient PV cell, then 90% of the energy that strikes that cell must be rejected as waste heat. To convey that waste heat to the ambient medium (air) the cell will assume a equilibrium temperature that is sufficiently elevated to conduct this waste heat to the air. The higher this equilibrium temperature, the worse the performance of the PV cell. Systems that use concentrated sunlight on PV arrays must use active cooling (either with water or ammonia or some other coolant) to avoid degrading the PV cell performance so badly that the efficiency is completely shot.

Dealing with the problems of heat rejection is not only endemic to all heat engines, like nuclear and solar thermal, but is fundamentally a part of systems like photovoltaics, whether we like it or not."