Nuclear energy: for or against?

[russ_watters]

People cited the Three Gorges Dam, but I'm not sure the relevant fact was ever stated: It displaced 1.3 million people. The equivalent nuclear disaster would be something like Limerick Nuclear Plant in southeastern Pennsylvania (where I live) going Chernobyl and making Philadelphia uninhabitable.

 

[mheslep]

Well, nuclear weapons have a different isotopic composition and distribution scheme.

Sure, but unlike leaks from a shutdown reactor, weapons have a colossal neutron flux (still ~10e12 N/cm^2 at one mile for a 15 kt weapon, pg 13) that make things in line of sight of the detonation a candidate for activation and thus a further source of radiation.

 

[mheslep]

2.5 GW in full vertical sunlight needs an area of roughly 10km^2, with a realistic solar flux and averaged over a year this is more like 50-100km^2. And then you still need to store the energy somehow, as the sun rarely shines at night.

Agreed, if that was for collection by ~20% efficient photovoltaic panels. Interestingly, that area, ~50+ km^2, is just the amount of the of land drown by the man made lake built solely for cooling the reactor in Virginia closest to me.

 

[mheslep]

Tidal power has been studied since at least the 1950s and France built a practical demonstrator at Rance, using a tidal basin with low speed turbines to tap the water flow energy. There has not been a larger unit built since afaik, so clearly the economics are hard to justify. ...

One reason being that tidal is also an intermittent, though predictable, power source. The cost of storage and/or other backup still has to be eventually added, like the other intermittent sources.

 

[mheslep]

Do the math then the engineering...

Here's a map of available solar energy per day for every month, let's pick March...

...

Now the US electrical consumption in 2011 was 3.75 X 10^12 kwh
http://www.ipsr.ku.edu/ksdata/ksah/energy/18ener7.pdf

... requiring 2.27 X10^10 square meters of collector.

The US has area of 9.16 X 10^ 12 square meters of land area
http://en.wikipedia.org/wiki/List_of_U.S._states_and_territories_by_area
and \frac{2.27E10}{9.16E12} = .0025
so covering ~1/4% of the whole country with solar panels could make as much electricity as we used in 2011.

... I suspect their immense size would wreak political havoc with suburbia..

Thoughts ? Corrections ?

Nice. I get roughly the same, with a couple of comments.

I find it quicker to express demand in units of average power (428 GWe, 2011). I think the most useful solar flux maps are flat plat tilted at latitude (http://rredc.nrel.gov/solar/old_data/nsrdb/1961-1990/redbook/atlas/colorpdfs/208.PDF), showing the annual average solar flux ranges from four hours of 1 kW power a day up to six or seven such hours in the southwest. That's a useful way to think about the subject since the actual solar flux hitting the ground does actually peak out at ~1kW - something to keep in mind if the collection method is pure thermal like solar hot water instead of photovoltaic, or the efficiency of PV jumps.

So then your figure with three hours is ~22 thousand sq km to produce the same average annual power demand, or about 150 km on a side. That sounds like a lot of land until it is compared to some other, current uses. I think you'll find existing rooftop areas, homes and warehouses, will about cover it. The single US military base out in White Sands, NM has an area of a similar order of magnitude. So too the existing highway system.

Serious problems do appear with the seasonal variation, as you mention. In January, http://rredc.nrel.gov/solar/old_data/nsrdb/1961-1990/redbook/atlas/colorpdfs/209.PDF in the northern third of the country. This has a couple implications. If the annual fraction of daily power produced by solar is to stay constant through January, then the amount of installed solar has to be doubled or quintupled, at least, and the same goes for the daily storage.

Germany's big solar push reflects these facts and shows that, at those latitudes, the difference between winter and summer collection can be 20 or 25 to 1. That kind of over installation and storage is a non-starter. This means we're in effect required to *keep* a good part of the existing power system sitting on standby for the winter. That is, keep a big part of the existing power system that supplies 428 GWe from coal, gas, nuclear and hydro sitting around to run 3-6 six weeks a year: an expensive proposition.

 

[nikkkom]

So then your figure with three hours is ~22 thousand sq km to produce the same average annual power demand, or about 150 km on a side. That sounds like a lot of land until it is compared to some other, current uses.

I advise anyone to go to google maps and take a good hard look at satellite image of US southwest: Nevada, Utah, Arizona, New Mexico. A *huge* chunk of land, sparsely populated, not very usable for agriculture.

Germany's big solar push reflects these facts and shows that, at those latitudes, the difference between winter and summer collection can be 20 or 25 to 1.

I see Germany's solar push as mostly a way to speed up R&D in PV. For Europe and Africa, it will make a lot of sense to eventually use Sahara, not Northern or Central Europe, as its primary solar power generation area.

 

[a.ua.]

but the Sahara as far away from Fukushima or Kiev.

So then your figure with three hours is ~22 thousand sq km to produce the same average annual power demand, or about 150 km on a side

almost equal to or even greater area of the "exclusion zone"
===================================================
In addition, Saudi Arabia and Jordan are building (planning to build) nuclear power plant.
Although they have a lot of sun.

 

[mheslep]

I advise anyone to go to google maps and take a good hard look at satellite image of US southwest: Nevada, Utah, Arizona, New Mexico. A *huge* chunk of land, sparsely populated, not very usable for agriculture.

True, and with little water its difficult to build any kind of traditional Rankine cycle power plant in the area. Solar's perfect in that regard.

On the other hand, being in the middle of nothing means it also a long way from that which uses the power. Note that transmission of solar and wind is not only expensive because of the long distances, it is expensive also because the transmission resource sits idle much of the time. That is, transmission developers count on power on the line staying relatively steady. In the case of solar the line is idle ~80% of the time. That drives up the cost per unit energy delivered by a factor of five.

 

[mheslep]

but the Sahara as far away from Fukushima or Kiev.

almost equal to or even greater area of the "exclusion zone"

For Fukushima? Isn't that 20 km long, and slowly shrinking?

 

[etudiant]

I see Germany's solar push as mostly a way to speed up R&D in PV. For Europe and Africa, it will make a lot of sense to eventually use Sahara, not Northern or Central Europe, as its primary solar power generation area.

German energy policy is a shambles.
Major players in alternative energy such as Siemens for wind or Bosch for solar are looking to exit their involvement, partly because super aggressive Chinese competition has made their production unprofitable. That curtails new R&D pretty thoroughly.
Meanwhile, the German public is balking at the much higher energy prices needed to support the shift to 'green power', as it is at allowing the large transmission and switching installations needed to hook up the wind farms to the industrial centers.
The upshot is that the German coal fired power plants are doing great!

 

[a.ua.]

mheslep

For Fukushima? Isn't that 20 km long, and slowly shrinking?

there is a "language", but I do not know the exact measurement of the area.
Our area of alienation also decreases.
Now, luxury cottages with barbed wire border zone.

 

[nikkkom]

but the Sahara as far away from Fukushima or Kiev.

Gibraltar is only 14 km wide.
Distance from the coast of Tunisia to Sardinia is about 100 km.
There are existing undersea HVDC lines much longer than this (~500 km).

 

[Argentum Vulpes]

I advise anyone to go to google maps and take a good hard look at satellite image of US southwest: Nevada, Utah, Arizona, New Mexico. A *huge* chunk of land, sparsely populated, not very usable for agriculture...

And I can think of 14 reasons that would never work in Nevada. From the same link 14 in Utah, 24 in Arizona, and 16 in New Mexico.

Also to note that Germanys push for green energy had caused problems with not only there electrical grid, but the electrical grids of neighboring countries. This instability of power in country had forced several large manufactures to purchase costly backup generators, or costly battery backup systems to prevent damage to there equipment. Also these power spikes from Germany has forced several neighboring countries to install electrical grid disconnect switches on the borders. Finlay Germans pay much higher electrical costs ($0.34 per kWh) then the average US resident ($0.12 per kWh)

The US needs to take a good long hard look at this green energy moment, especially with the boondoggle it has become in Spain and now Germany.

Source for the German power woes link

 

[mheslep]

And I can think of 14 reasons that would never work in Nevada. From the same link 14 in Utah, 24 in Arizona, and 16 in New Mexico...

Endangered species will stop solar PV deployment? I've read about some law suits to stop solar PV farms but so far they a appear to have failed. In any case the endangered species act won't stop PV on top of warehouses or over parking lots.

 

[nikkkom]

German energy policy is a shambles.
Major players in alternative energy such as Siemens for wind or Bosch for solar are looking to exit their involvement, partly because super aggressive Chinese competition has made their production unprofitable.

Why should consumer care? If equivalent Chinese PV panels are cheaper, so be it.

Meanwhile, the German public is balking at the much higher energy prices needed to support the shift to 'green power'

Since it was German public, no one else, who forced nuclear phase-out, I am not believing you.

 

[Argentum Vulpes]

Endangered species will stop solar PV deployment? I've read about some law suits to stop solar PV farms but so far they a appear to have failed. In any case the endangered species act won't stop PV on top of warehouses or over parking lots.

Yes it won't stop putting PV on top of existing structures or over roadways/parking lots. However if a planed project even remotely encroaches on critical environment of an endangered species say good by to the project.

The post was also more directed at Nikkkom's veiled comment at turning the American SW into a giant solar farm

* After reading the link a bit more carefully it also appears that the tortuous in question that the Sierra Club, Defenders of wildlife, and Natural Resources Defense Council, used as a basis for their lawsuits is only threatened under the Endangered species act. Even though threatened species are protected by the act, it allows for more leeway in projects that encroach on habitat of threatened species.

On a side note the project the article sites has been abandoned due changing market conditions. http://www.pe.com/local-news/local-news-headlines/20130624-barstow-calico-solar-plans-withdrawn.ece

 

[nikkkom]

Yes it won't stop putting PV on top of existing structures or over roadways/parking lots. However if a planed project even remotely encroaches on critical environment of an endangered species say good by to the project.

The post was also more directed at Nikkkom's veiled comment at turning the American SW into a giant solar farm

On a side note the project the article sites has been abandoned due changing market conditions. http://www.pe.com/local-news/local-news-headlines/20130624-barstow-calico-solar-plans-withdrawn.ece

Some projects fail, others already generate power.
Check these on Wikipedia:

Agua Caliente Solar Project
Installed capacity 250 MW, maximum planned 397 MW
California Valley Solar Ranch
Installed capacity 22 MW (Oct 2012), maximum planned 250 MW
Copper Mountain Solar Facility
Installed capacity 150 MW, maximum 418 MW
Catalina Solar Project
Installed capacity 60 MW, maximum 143 MW
Mesquite Solar project
Installed capacity 150 MW, maximum 700 MW

Use the map link to see them in Google Maps with your own eyes. Gives quite a perspective on their size, simplicity, and the vast areas of undeveloped desert available for expansion.
This is really happening, despite eco-nazis' attempts to return us to life in caves.
You just refuse to read the writing on the wall.

 

[russ_watters]

What is happening? All of those projects put together, if finished, will only equal the kW capacity of one nuclear plant and have a kWh capacity of about one sixth of a nuclear plant. That's still a long way from breaking out of the "other" category on a pie chart.

 

[QuantumPion]

What is happening? All of those projects put together, if finished, will only equal the kW capacity of one nuclear plant and have a kWh capacity of about one sixth of a nuclear plant. That's still a long way from breaking out of the "other" category on a pie chart.

Not even, keep in mind the capacity factor of solar is like 15% while nuclear is >90%.

 

[mfb]

Why should consumer care? If equivalent Chinese PV panels are cheaper, so be it.

They appear cheap as the government (and therefore all taxpayers) throws money on it. They are not really cheap.

Since it was German public, no one else, who forced nuclear phase-out, I am not believing you.

A significant fraction of them did not think about the consequences.

 

[russ_watters]

Not even, keep in mind the capacity factor of solar is like 15% while nuclear is >90%.

I did say that...

 

[Argentum Vulpes]

Some projects fail, others already generate power.
Check these on Wikipedia:

Agua Caliente Solar Project
Installed capacity 250 MW, maximum planned 397 MW
California Valley Solar Ranch
Installed capacity 22 MW (Oct 2012), maximum planned 250 MW
Copper Mountain Solar Facility
Installed capacity 150 MW, maximum 418 MW
Catalina Solar Project
Installed capacity 60 MW, maximum 143 MW
Mesquite Solar project
Installed capacity 150 MW, maximum 700 MW

Use the map link to see them in Google Maps with your own eyes. Gives quite a perspective on their size, simplicity, and the vast areas of undeveloped desert available for expansion.
This is really happening, despite eco-nazis' attempts to return us to life in caves.
You just refuse to read the writing on the wall.

Just to repeat some of what was said and to expand on it, let's compare the numbers of these 5 plants to Palo Verde NNP

........Palo Verde.....5 PV projects
Power produced...3.3 GW.....1.9 GW
Capacity Factor...98%......25% (Best one)
Acers used.....4.4k......9.3k

Still not seeing how Solar and wind are going to be able to replace or exclude nuclear power any time in the near or distant future.

As for the writing on the wall four top environmental scientist say that nuclear power must be used to fight future irrecoverable damage to global climate.

 

[nikkkom]

Apparently this part is being willfully ignored:

"""
Use the map link to see them in Google Maps with your own eyes. Gives quite a perspective on their size, simplicity, and the vast areas of undeveloped desert available for expansion.
"""

 

[mfb]

Apparently this part is being willfully ignored:

"""
Use the map link to see them in Google Maps with your own eyes. Gives quite a perspective on their size, simplicity, and the vast areas of undeveloped desert available for expansion.
"""

The Mesquite Solar project has the Palo Verde nuclear power plant nearby (~5km NE), you can directly compare them. And the PV project is still growing.

 

[HowlerMonkey]

I'm for safe nuclear power.

In that, I mean reactors that don't have to be continually fed power to keep them from burning up.

A reactor were designed with a convective cooling loop that could tolerate not having the grid or diesel generators would be fine with me.

Anything less is just tempting fate.

 

[Argentum Vulpes]

The Mesquite Solar project has the Palo Verde nuclear power plant nearby (~5km NE), you can directly compare them. And the PV project is still growing.

And how does 700MW compare with 3.3GW?

Again Nikkkom trying to cover the American southwest desert in PV panels will never work. Let's try something different, tell me how many sq miles you want covered in PV panels, and do a quick back of the envelope calculation.

1 kW per sq meter of land covered (best case)
44.7% efficacy of solar PV panel (best case, still in the lab)
And finally for kicks and giggles, how is power going to be supplied at night and made up during non peak times and days?

 

[jadair1]

I'm for safe nuclear power.

In that, I mean reactors that don't have to be continually fed power to keep them from burning up.

A reactor were designed with a convective cooling loop that could tolerate not having the grid or diesel generators would be fine with me.

Anything less is just tempting fate.

This is an issue I have as well.

If NPP are so efficient why do they need outside power to keep them going, shouldn't they be able to provide their own electricity if outside power is lost and the reactors have not scrammed?

I know of Pulp Mills in BC that not only supply all their internal power and send the excess to the grid, it is only when the power and recovery boilers are both offline that they need any energy from the grid.

As a matter of fact the Intercon pulp mill in BC would not be licenced by the then current Socred Government unless it was built without a power boiler so that they would have to buy power from the recently built WACY Bennet Damn on the Peace River.

 

[russ_watters]

If NPP are so efficient why do they need outside power to keep them going...

NPPs are pretty inefficient, but that doesn't have anything to do with why they need outside power.

The reason they need outside power is for when the plant isn't generating its own power to run its cooling systems.

It sounds like you think nuclear plants are net users of electricity, not generators!

...shouldn't they be able to provide their own electricity if outside power is lost and the reactors have not scrammed?

You have the issue backwards in two different ways:
1. If there is no connection to the grid, there is nowhere for the heat generated by the plant to go. It has to shut down to prevent overheating if it is not generating electricity for the grid.
2. As a matter of safety, a nuclear plant must have several backups and when backups are lost, they are shutdown whether they really need to be or not.

 

[jadair1]

NPPs are pretty inefficient, but that doesn't have anything to do with why they need outside power.

For the most part all of our current Power Generating Systems are pretty innefficient, I don't think I can think of one that has close to 20% efficiency.

The reason they need outside power is for when the plant isn't generating its own power to run its cooling systems.

My problem with this is that most NPP facilities have multiple reactors so there would be no reason to have them all ofline at the same time unless it was a catastrophic failure such as Fukushima was.

Of course when a plant is connected to the grid the power can run either way when needed..

It sounds like you think nuclear plants are net users of electricity, not generators!

No, I do not think that, not at all. I believe they are very ineficient and ony exist to produce plutonium for the war machine but that is a different conversation.


You have the issue backwards in two different ways:
1. If there is no connection to the grid, there is nowhere for the heat generated by the plant to go. It has to shut down to prevent overheating if it is not generating electricity for the grid.

Do you mean there is no way to shed heat if they are not producing electricity?

Can they not continue to run the turbines and shunt the electricity produced somewhere, perhaps banks of resistors and capacitors and bled to ground if need be, this seems like a simple design flaw to me.

2. As a matter of safety, a nuclear plant must have several backups and when backups are lost, they are shutdown whether they really need to be or not.


The first backup would be the other reactors that are online, if all reactors go offline due to an accident, (a very uncommon event I believe it has only happened once), then the secondary source would be the grid and the tertiary source would be the diesal generators onsite.

The grid is the second backup, the other plants in the facility are the first backup in my opinion.

 

[mfb]

And how does 700MW compare with 3.3GW?

That's exactly my point.

 

[russ_watters]

For the most part all of our current Power Generating Systems are pretty innefficient, I don't think I can think of one that has close to 20% efficiency.

Er, no - the only kind that is that inefficient is solar power. All the rest are more efficient.

No, I do not think that, not at all. I believe they are very ineficient and ony exist to produce plutonium for the war machine but that is a different conversation.

Oy. That's basically conspiracy theory. Why don't you google the efficiency of a few different types of power plants, starting with nuclear.

And you have the issue of plutonium and nuclear weapons precisely backwards: We're not making plutonium for weapons, we are decommissioning weapons and using the plutonium to make power. The US and Russia have slashed the number of nuclear weapons they have: http://www.nytimes.com/2009/11/10/business/energy-environment/10nukes.html?_r=0

Do you mean there is no way to shed heat if they are not producing electricity?

Of course there is: you run pumps and the cooling tower. But to run pumps while not producing electricity, you need to get electricity from your backup generators or the grid.

Can they not continue to run the turbines and shunt the electricity produced somewhere, perhaps banks of resistors and capacitors and bled to ground if need be, this seems like a simple design flaw to me.

A bank of resistors still produces heat that needs to be dissipated, but you're still missing the point: the generation system itself can fail. That's precisely what happened at Three Mile Island - and while the other reactor on site was down for refueling:
http://en.wikipedia.org/wiki/Three_Mile_Island_accident#Accident

It seems like you have a lot of severe misunderstandings about nuclear and conventional power generation that make almost everything you think you know wrong!

 

[jadair1]

It seems like you have a lot of severe misunderstandings about nuclear and conventional power generation that make almost everything you think you know wrong!

http://www.mpoweruk.com/energy_efficiency.htmNuclear
The efficiency of nuclear plants is little different. On the steam turbine side they use the Rankine thermodynamic cycle with steam temperatures at saturated conditions. This gives a lower thermal cycle efficiency than the high temperature coal fired power plants. Thermal cycle efficiencies are in the range of 38 %. Since the energy release rate in nuclear fission is extremely high, the energy transferred to steam is a very small percentage - only around 0.7 %. This makes the overall plant efficiency only around 0.27 %. But one does not consider the fuel efficiency in nuclear power plants; fuel avaliabity and radiation losses take center stageFromitachi Power Group

Efficiencies
Saving on resources, reducing emissions

Across the world, power plants have on average only a 30% efficiency – the figure for plants in Germany is around 38%. The ongoing new power plants are designed for an approx. 45% efficiency. This means that new plants need less fuel for the same amount of electricity and thus their emissions output is correspondingly less.

Power plant operators and plant constructors are researching intensively across the world into new processes and materials to raise efficiencies still further. This is also where Hitachi Power Europe is very much engaged in R&D.

On the way to the 700°C power plant: higher temperatures (700°C) and pressures (350 bar) can significantly raise the efficiency of a traditional coal power plant. However, what is firstly needed are new materials. In its own production facilities, Hitachi Power Europe manufactures those special-purpose alloys and components for these highly efficient power plants of tomorrow.

Lower moisture contents equate with a higher calorific value: lignite pre-drying can achieve a rise in this fuel's efficiency. Hitachi Power Europe is developing the requisite firing technologies and components for lignite-fired plants.

Ultra-modern IT instruments for an optimally designed plant: processes and the service lives of system parts can be optimized even at the power plant design stage. This more than saves on costs later on under actual operations. The future will see power plant simulations on the computer being used to monitor equipment and systems online.

So my memory is failing me, I have not looked at these things for many years and I got an off the top of my head number wrong.

But if you look at the table I linked to you will see that Nuclear is the least efficient of all the major conventional power sources. Not to mention the 99.3% of the energy that is not converted to steam in a NPP, can you imagine if that wasted energy could be harvested in some way.

 

[QuantumPion]

http://www.mpoweruk.com/energy_efficiency.htm


Nuclear
The efficiency of nuclear plants is little different. On the steam turbine side they use the Rankine thermodynamic cycle with steam temperatures at saturated conditions. This gives a lower thermal cycle efficiency than the high temperature coal fired power plants. Thermal cycle efficiencies are in the range of 38 %. Since the energy release rate in nuclear fission is extremely high, the energy transferred to steam is a very small percentage - only around 0.7 %. This makes the overall plant efficiency only around 0.27 %. But one does not consider the fuel efficiency in nuclear power plants; fuel avaliabity and radiation losses take center stage

...

So my memory is failing me, I have not looked at these things for many years and I got an off the top of my head number wrong.

But if you look at the table I linked to you will see that Nuclear is the least efficient of all the major conventional power sources. Not to mention the 99.3% of the energy that is not converted to steam in a NPP, can you imagine if that wasted energy could be harvested in some way.

There are a few inaccurate statements here resulting from a lack of knowledge of nuclear power and basic thermodynamic concepts. First of all, the energy deposited by fission in the fuel is 97.4%. The missing 2.6% is energy lost due to neutrinos. All of the remaining energy eventually transfers to the coolant and ultimately the environmental heat sink.

Secondly, you have an extra decimal place in your figures, the efficiency is around 35% not 0.35%.

Last and most importantly, the total thermal efficiency of the plant is a function of the maximum temperature difference between ambient temperature and hot steam temperature. Typical nuclear power reactor efficiencies range from 33% to 40% depending on design. PWR's and BWR's have a bit lower thermal efficiency compared to fossil fuel plants due to the inability to create superheated steam. However this is simply the thermodynamic efficiency of the plant in terms of how many MW-electrical are generated for each MW-thermal produced and has nothing to do with economic efficiency (uranium is much cheaper than coal therefore it is not an apples-to-apples comparison).

 

[mfb]

However this is simply the thermodynamic efficiency of the plant in terms of how many MW-electrical are generated for each MW-thermal produced and has nothing to do with economic efficiency (uranium is much cheaper than coal therefore it is not an apples-to-apples comparison).

Exactly. If I would have a way to generate infinite amounts of antimatter without costs (both money and energy), and if I can use them in a power plant with 10% efficiency, I don't care about that value at all. To generate more power, I would just produce and burn more antimatter.


jadair1: please surround quotes with [noparse][/noparse]-tags. Don't pretend that this text is from you.

 

[gmax137]

Nuclear
The efficiency of nuclear plants is little different. On the steam turbine side they use the Rankine thermodynamic cycle with steam temperatures at saturated conditions.

True enough. Most nukes do make saturated steam. There are reactor designs that produce superheated steam, but not like a modern coal-burner.

This gives a lower thermal cycle efficiency than the high temperature coal fired power plants.

True.

Thermal cycle efficiencies are in the range of 38 %.

True. That means 38% of the reactor core power leaves as electrical megawatts. The rest goes out through the cooling towers. The coal stations do the same thing, only it's more like 45% of the boiler power goes out as electric power.

Since the energy release rate in nuclear fission is extremely high, the energy transferred to steam is a very small percentage - only around 0.7 %.

False. All of the heat generated in the fuel is transferred to the steam (otherwise, the core would heat up continuously). I'm baffled by what this is trying to say. It doesn't make any sense.

This makes the overall plant efficiency only around 0.27 %.

Gibberish. See above.

But one does not consider the fuel efficiency in nuclear power plants; fuel availability and radiation losses take center stage

Partly true - reactor fuel is considerably cheaper than fossil fuel in terms of $/Btu. That's one reason why it is worth the extra capital cost to build a nuclear unit. That doesn't mean the nuclear operators don't care about fuel cost, they do. But it isn't the dominating consideration that it is for the gas-burner or coal-burner. And that's why the fossil fuel interests (the gas drillers and coal mine owners) are so opposed to nuclear power. It cuts them out of the gravy train.

I don't know what the "radiation losses" are referring to.

 

[QuantumPion]

I don't know what the "radiation losses" are referring to.

I'm guessing neutrinos but I don't think he really knows what he's talking about, he is mixing up different concepts.

 

[nikkkom]

And how does 700MW compare with 3.3GW?

Again Nikkkom trying to cover the American southwest desert in PV panels will never work. Let's try something different, tell me how many sq miles you want covered in PV panels, and do a quick back of the envelope calculation.

1 kW per sq meter of land covered (best case)
44.7% efficacy of solar PV panel (best case, still in the lab)
And finally for kicks and giggles, how is power going to be supplied at night and made up during non peak times and days?

I did it on this forum already about a year ago. Be my guest:

Insolation: ~1kW/m^2
PV efficiency: growing by the day, but let's assume conservatively that it will never exceed 10% for economically viable multi-km^2 installations.
Losses due to night / clouds / rain: 4/5, but let's assume higher losses: 9/10.

Thus, 1 m^2 can produce only 10W on average. 1 km^2 can produce 10 MW.

Mostly desert and dry US states:

Arizona: 295254 km^2
Nevada: 286367 km^2
New Mexico: 315194 km^2

Sum: 896815 km^2

If we would tile only 10% of this land with PV panels we'd generate 897 GW (on average). And then there are dry, inhospitable areas in Utah, Colorado and Texas if we would ever need more.

Total installed electricity generation capacity in the United States today is a bit above 1000 GW.

 

[mfb]

...and then it gets night and you try to use your average 897 GW to operate a single light bulb.
The US has certainly enough desert area for PV. Assuming those deserts are suitable for it (I don't know which fraction will have issues with sand). But then you still have the high costs and the storage issue. And many countries don't have so many deserts.

 

[mheslep]

What is happening? All of those projects put together, if finished, will only equal the kW capacity of one nuclear plant and have a kWh capacity of about one sixth of a nuclear plant. That's still a long way from breaking out of the "other" category on a pie chart.

In the case of solar it will increasingly be mistake to point to large central installation as the sum all efforts, which neglects all the distributed residential, small projects. This source indicates US solar capacity will be 10 GWe by the end of the year, or about two nuclear reactor equivalents, with new solar coming on at a rate of another 4 GW per year at this time, i.e. a new reactor equivalent every year and half. One drawback of nuclear is that, if a utility starts planning for a new reactor today, their first power is probably 10 years away.

 

[mheslep]

I did it on this forum already about a year ago. Be my guest:

Insolation: ~1kW/m^2
PV efficiency: growing by the day, but let's assume conservatively that it will never exceed 10% for economically viable multi-km^2 installations.
Losses due to night / clouds / rain: 4/5, but let's assume higher losses: 9/10.

Thus, 1 m^2 can produce only 10W on average. 1 km^2 can produce 10 MW.

That's low by 2 or 3X. The one km^2 insolation is 1 GW, peak, as you say. Conversion minimum now is 15%, 20% on the expensive side, so 150 MW per km^2. Capacity factor in Arizona is 25% (6 kWh insolation per m^2 per day). Resulting daily average power is then 30 MW/km^2. Call it 20 MW/km^2 with wasted land. US average power load is ~430 GWe, which is supplied then by ~22e3 km^2 of PV, or 150 km on a side, a tiny parcel of what's called the US southwest.

 

[BruceW]

...and then it gets night and you try to use your average 897 GW to operate a single light bulb.
The US has certainly enough desert area for PV. Assuming those deserts are suitable for it (I don't know which fraction will have issues with sand). But then you still have the high costs and the storage issue. And many countries don't have so many deserts.

I guess the problem is that at the moment, there are more commercially advantageous ways of making electricity. Maybe in a few years when fossil fuels run out, such projects will be commercially more viable (as well as nuclear power). But ideally we wouldn't want to use all our fossil fuels and pollute the world that much with them. So then the problem is if we can motivate ourselves enough to choose the less commercially viable options, and/or to invest more into research into making green technologies more commercially viable.

 

[jadair1]

Exactly. If I would have a way to generate infinite amounts of antimatter without costs (both money and energy), and if I can use them in a power plant with 10% efficiency, I don't care about that value at all. To generate more power, I would just produce and burn more antimatter.


jadair1: please surround quotes with [noparse][/noparse]-tags. Don't pretend that this text is from you.

Sorry, I did not mean to imply that text was from me.

I thought it was apparent from the link I posted with the excerpt taken from it and the preface from the other stating:

From the Hitachi Power Group: etc.

I do not imagine how anyone could think it was my work!

I will endeavor to make things clearer I am still finding my way around here.

BTW I really appreciate the education I am receiving here, it has been a long time since I have associated with people with this type of education and experience.

I have been in the construction business since my tech company collapsed in 2000, not that these are stupid people I am working with, far from it, but I doubt many know how to solve Complex Fourier Equations, Control Theory or Advanced Linear Equations.

Hell, I used to be a wiz at these but it has been so long since I have used any I would need to take refreshers in basic courses such as Calculus before I could even dream of tackling any of them again.

Sorry, off topic, I'm really here to learn.

 

[jadair1]

True enough. Most nukes do make saturated steam. There are reactor designs that produce superheated steam, but not like a modern coal-burner.



True.



True. That means 38% of the reactor core power leaves as electrical megawatts. The rest goes out through the cooling towers. The coal stations do the same thing, only it's more like 45% of the boiler power goes out as electric power.



False. All of the heat generated in the fuel is transferred to the steam (otherwise, the core would heat up continuously). I'm baffled by what this is trying to say. It doesn't make any sense.



Gibberish. See above.



Partly true - reactor fuel is considerably cheaper than fossil fuel in terms of $/Btu. That's one reason why it is worth the extra capital cost to build a nuclear unit. That doesn't mean the nuclear operators don't care about fuel cost, they do. But it isn't the dominating consideration that it is for the gas-burner or coal-burner. And that's why the fossil fuel interests (the gas drillers and coal mine owners) are so opposed to nuclear power. It cuts them out of the gravy train.

I don't know what the "radiation losses" are referring to.

Sorry, that was not me talking it was quotes from Hitachi and the article I provided the link to, I thought that was clear.

Apparently it was not.

 

[jadair1]

I'm guessing neutrinos but I don't think he really knows what he's talking about, he is mixing up different concepts.

Correct, I am attempting to learn, there is so much information/disinformation on the net a little bit of knowledge is a dangerous thing!

 

[russ_watters]

In the case of solar it will increasingly be mistake to point to large central installation as the sum all efforts, which neglects all the distributed residential, small projects. This source indicates US solar capacity will be 10 GWe by the end of the year, or about two nuclear reactor equivalents, with new solar coming on at a rate of another 4 GW per year at this time, i.e. a new reactor equivalent every year and half.

I know it is getting redundant, but again I must point out that those numbers don't consider the low capacity factor or need for backup. Right now the need for backup can be ignored since the solar capacity is so low, but if it ever reaches a meaningful level, solar plants will basically all need identically sized natural gas plants built next door.

Solar generates the most power when needed most, but in some climates it is also likely to fail at those times: hot, humid summer days generate clouds.

 

[gmax137]

Sorry, that was not me talking it was quotes from Hitachi and the article I provided the link to, I thought that was clear.

Apparently it was not.

That's no problem, jadair, I was responding point by point to the posted text; it doesn't matter to me who wrote it. I'm not attacking you in any way - I'm just trying to shed light on these subjects.

 

[jadair1]

That's no problem, jadair, I was responding point by point to the posted text; it doesn't matter to me who wrote it. I'm not attacking you in any way - I'm just trying to shed light on these subjects.

Ok, thank you that that goes to my point of information/disinformation, I will read Global Research and Fairwinds articles as well as Tepco and IAEA. But I realize each has an agenda and what they have to say must be taken with a grain of salt.

For example the most strident anti-nukes are screaming that if spent fuel pool #4 collapsed spilling it's contents on the ground the whole site would need to be evacuated and all electronic systems on site would be fried causing the whole site to burn, explode or melt down depending on how strident the source is.

Personally I think the likelyhood of the pool collapsing is quite low as it has recentely survived a nearby 7.2 magnitude quake, but I would like to know the consequences of the worst case senario?

I know this should perhaps be in multiple Fukushima threads but the ongoing situation at Fukushima is the main reason for my recent conversion to the anti-nuke side from once being very pro-nuke.

And that is a position I am not totaly comfortable with.

 

[mheslep]

I know it is getting redundant, but again I must point out that those numbers don't consider the low capacity factor

Yes they do; I include the capacity factor for http://rredc.nrel.gov/solar/pubs/redbook/PDFs/AZ.PDF: 25% or 6 kWh/m^2 out of a 24 hour day (that's measured over many years: winter/summer, night/day, sunny/cloudy). At 100% CF we'd be talking about 150 MW/km^2 (total ~2900 km^2) instead of the 20-30 MW/km^2 (~22000 km^2).* I was mostly addressing Argentum Vulpes' comment that one would have to "cover" over the southwest US to supply the US load w/ solar PV. Hardly.

or need for backup.

True, no backup calculation nor transmission from the dessert. Both are requirements to go mainstream w/ solar I agree, but the calculation above is just for land sufficient to supply average power. That is, the land calculation includes enough solar to produce, during sunshine, four times the average long term load and thus assumes storage to hold the extra. Storage will take some more space but not a significant share of the solar collection area. The present problem with storage is of course cost, and I expect will be for some time.

Right now the need for backup can be ignored since the solar capacity is so low, but if it ever reaches a meaningful level, solar plants will basically all need identically sized natural gas plants built next door.

Agreed. That seems to be what's coming at least initially. The new ~.7GW solar thermal plant, Ivanhoe, is a hybrid with natural gas hookup to fire its boiler absent sun.

* I didn't discuss pure solar thermal collection for heating, e.g. for hot water. In that case we're back again to starting with 1 GW/km^2 for six hours per day in Az.

 

[D H]

CNN is broadcasting a documentary on nuclear power tonight. Knowing CNN, they'll bend over backwards to present both sides of the issue.

 

[jadair1]

CNN is broadcasting a documentary on nuclear power tonight. Knowing CNN, they'll bend over backwards to present both sides of the issue.

Did you forget the sarcasm smiley there my friend.