Nuclear energy: for or against?

[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.