YOU: Fix the US Energy Crisis

[signerror]

A good part of the difference in per person energy usage between US and the UK must be attributed to the population distribution over a large country and consequent transportation needs, and not so much to lifestyle differences. For further evidence see Canada, which covers a vast land area and has a higher per person energy usage than the US but with a slightly lower standard of living.

I question that. I suspect a large part of it is the climate difference, which result in much larger heating needs. For example, the Scandinavian countries also have anomalously high energy demand, but are comparatively tiny.

http://en.wikipedia.org/wiki/List_of_countries_by_energy_consumption_per_capita

power per capita:

Iceland - 15.6 kW
Canada - 11.0 kW
USA - 10.4 kW
Finland - 9.6 kW
Norway - 7.9 kW
Sweden - 7.7 kW
...
France - 6.0 kW
Germany - 5.6 kW
UK - 5.2 kW

 

[signerror]

Mackay's 125kWh/d breaks down as follows (major parts):

• Car: 40kWh/d
• Jet travel: 30kWh/d
• Heating/Cooling: 37 kWh/d
• Food/fertilizer: 14 kWh/d
• plus misc.

Cars, heating/cooling could be improved, but as a whole there's no cutting this in half.
Also, the 125 figure doesn't include energy spent on creating imported goods (47kWh/d).

Here are his demand and supply graphs:

 

[Astronuc]

$316 ! That book is made out of photovoltaic cells or what ??

There are a number of specialty texts in the range of $300-$500. That's certainly daunting to an undergrad or lay person.

Articles at ScienceDirect are $31.50 now. The journal subscriptions are $$$$$$.


Meanwhile - here is an interesting assessment of the prospects of nuclear energy in 1966.
THE NUCLEAR ENERGY REVOLUTION—1966
Alvin Weinberg (Physicist and Dir. of Oak Ridge National Laboratory) and Gale Young.
pdf download available.

Very optimistic were folks back then.

 

[drewk79]

I am truly impressed by all the discussion going on in this one single thread. I feel a a little wiser after reading the responses every day.

If you take Mackay"s general numbers into account it is obvious our domestic energy policy is a large animal. I would think the best way to tame such a large beast would be to give the tools to the billions of people around the world.

I think technology will advance and bring us new exciting ways to harness large amounts of energy in a more cost effective way.

I am more interested in technology scaling down the tech we have today into systems that individual people could implement.

Boyle's Law says (I am paraphrasing I apologize) gas will spread out and take up the entire volume of a container and then begin to pressurize.

I think residential energy consumption is similar to that. I know in my house electricity is so cheap(?) I just use what ever I feel necessary at that point in time. It seems plausible to me the rest of the country works on a similar process.

We will continue to use energy in this willy nilly manner until we reach a level that puts pressure on the system.

I would like to see a test program that puts a cap on energy usage. Maybe not a hard cap but maybe just a beeper on your meter that beeps once you reach a set number of kwh each day. I think some people would see their usage and make more of an effort to reduce consumption.

I may be wrong and people may already be living without wasting energy but, maybe not.

If we could start budgeting our energy throughout the day we may be able to slow the growth of energy consumption. This may be slim in its ability to solve our needs but with a beast this big every shot helps.

 

[vanesch]

I am more interested in technology scaling down the tech we have today into systems that individual people could implement.

Well, all bits help, but as MacKay says, if everybody does a little, we'll achieve... little.

There's nothing wrong with individual ways of gathering energy and saving energy. However, don't forget: effective solar energy: 20 W per square meter (depends on location), effective wind energy density: 2 W per square meter. This is not very "compact", so unless you have a large property, your distributed techniques will only contribute a certain part.

Also, energy technologies often have economies of scale, so large scale systems are very often more cost-effective (and effective overall) than distributed systems. Large windmills are more cost-effective than small individual turbines, for instance.

One should be careful, in finding a realistic energy policy, that one doesn't put extra ideological constraints on the "solution" such that no workable scheme for the near future comes out.

We will continue to use energy in this willy nilly manner until we reach a level that puts pressure on the system.

Very simple: multiply energy prices by, say, 50. You'll see an effect. Maybe not the effect hoped for.

 

[drewk79]

The 20 watt per sq meter effective solar number. Is that what solar cells can produce? Or is that the total energy the sun puts out? thanks?

 

[drewk79]

Very simple: multiply energy prices by, say, 50. You'll see an effect. Maybe not the effect hoped for.

Over the past few years we saw gas prices soar. What happened i think was, people did not stop driving because it has become a necessity. Instead people stopped doing everything else.

I would imagine electricity prices rising dramatically would do the same.

Also the energy prices do not have to be the ones to go up to cause pressure. If people have less money due to a smaller paycheck or higher costs for other products this would cause the same pressure as energy prices jumping.

If we implement all the small ideas today we will have a big result tomorrow.

There are so many pages to this thread. Is there a summary post somewhere with all the ideas in one place? Or should I write one?

 

[Astronuc]

The 20 watt per sq meter effective solar number. Is that what solar cells can produce? Or is that the total energy the sun puts out? thanks?

See here - http://en.wikipedia.org/wiki/Solar_constant#Solar_constant

PV's use part of the spectrum, and then there is a conversion efficiency.

So if PV's are 10% efficient and the flux is 1000 W/m², then a PV would produce 100 W/m² of useful electrical energy. There maybe further losses depending on resistance (dependent on distance between supply and load) and other conversion losses.


With respect to conservation and utilization of energy, Rocky Mountain Institute has many interesting articles.
http://www.rmi.org/

http://move.rmi.org/features/oilmap.html

 

[russ_watters]

The "250 KWhr/day per person" in the US is divided by 2, simply because his argument is based upon the UK, and there, energy consumption is about half of it, 125 KWhr/day per person, and he has all his numbers ready for this quantity.

Now, living standards are higher in the US than in Europe, but one is nevertheless left with the sentiment that there must be more potential for simple economies of energy in the US without affecting lifestyle, as energy-saving measures which are already in place since long in Europe are not so much applied in the US as far as I understand. Now, as living standards in the US are higher, it will probably not be possible to bring US consumption down to Europe's consumption (halving), but some diminishing must surely be feasible.

There are two major reasons that [much of] Europe uses less energy per capita than the US, besides living standard:

1. Population distribution/density results in substantailly lower transportation energy usage.
2. The weather in Europe is far more stable than the US. England has roughly the same annual heating degree days as Philadelphia, but only a tiny fraction of the cooling degree days.

The first reason will probably change a little as people start living closer to where they work as transportation costs continue to rise, the second won't change much (if anything, global warming will improve it for Europe).

 

[signerror]

So if PV's are 10% efficient and the flux is 1000 W/m², then a PV would produce 100 W/m² of useful electrical energy. There maybe further losses depending on resistance (dependent on distance between supply and load) and other conversion losses.

1000 W/m² is the peak flux. If you average over time, you have a much lower "effective" power which is what is meaningful for counting total energy contributions. Over the continental US, the solar irradiation ranges from 4-7 kWh/day, which is about 170-290 W/m^2 average. So take 10% of that, and you get 17-29 W/m^2 of electricity, which is what vanesch is quoting.

 

[vanesch]

The 20 watt per sq meter effective solar number. Is that what solar cells can produce? Or is that the total energy the sun puts out? thanks?

signerror already gave the answer. Of course, this is dependent on the region and so on. It is what MacKay quotes for photovoltaic
http://www.inference.phy.cam.ac.uk/withouthotair/c6/page_39.shtml
in the UK, and also what he quotes for thermal solar in the North-African desert:
http://www.inference.phy.cam.ac.uk/withouthotair/c25/page_182.shtml

These are ballpark numbers of course.

 

[mheslep]

signerror already gave the answer. Of course, this is dependent on the region and so on. It is what MacKay quotes for photovoltaic
http://www.inference.phy.cam.ac.uk/withouthotair/c6/page_39.shtml
in the UK, and also what he quotes for thermal solar in the North-African desert:
http://www.inference.phy.cam.ac.uk/withouthotair/c25/page_182.shtml

These are ballpark numbers of course.

Hey, page by page online references now. Great way to access a book.

 

[OmCheeto]

My oh my. Reading some of the excerpts attributed to Professor MacKay made him sound like a bit of a kook. And that after I complemented him:

...
Kind of refreshing to hear from a professor of physics rather than Geraldo.
...

I think I read half his book online yesterday. I found his personal opinions and actions very much in line with both mine and some people at the forum:

1. He cut his own home energy use to one quarter over a 14 year period(50kwh/day --> 13kwh/day). http://www.inference.phy.cam.ac.uk/withouthotair/c21/page_143.shtml
I only cut mine in half. But I just started a year ago.

2. Sometimes it's difficult to tell when he's being sarcastic. Which would he prefer: Trams, bicycles, or electric cars?

http://www.inference.phy.cam.ac.uk/withouthotair/c20/page_127.shtml
I’ve looked up the performance figures for lots of electric vehicles –
they’re listed in this chapter’s end-notes – and they seem to be consistent
with this summary: electric vehicles can deliver transport at an energy cost
of roughly 15 kWh per 100 km. That’s five times better than our baseline
fossil-car, and significantly better than any hybrid cars. Hurray! To achieve
economical transport, we don’t have to huddle together in public transport
– we can still hurtle around, enjoying all the pleasures and freedoms of solo
travel, thanks to electric vehicles.

3. Regenerative braking on hybrid vehicles. (Not the marketed ones on the road right now, but the improved prototypes):

http://www.inference.phy.cam.ac.uk/withouthotair/c20/page_126.shtml
Regenerative systems using flywheels and hydraulics seem to work a
little better than battery-based systems, salvaging at least 70% of the brak-
ing energy.

4. Carrying around solar panels on your car? I've never seen this advocated except by kooks.

http://www.inference.phy.cam.ac.uk/withouthotair/c20/page_131.shtml
Q: I live in a hot place. How could I drive an electric car? I demand
power-hungry air-conditioning!

A: There’s an elegant fix for this demand: fit 4 m² of photovoltaic panels
in the upward-facing surfaces of the electric car. If the air-conditioning is
needed, the sun must surely be shining. 20%-efficient panels will generate
up to 800 W, which is enough to power a car’s air-conditioning. The
panels might even make a useful contribution to charging the car when
it’s parked, too. Solar-powered vehicle cooling was included in a Mazda
in 1993; the solar cells were embedded in the glass sunroof.

I actually did something like that when my serpentine belt tensioner broke off one day. I was too cheap to have the car towed home so I installed the 3 panels to replace the alternator for the 15 mile drive home. Worked fine.

And no. You can't permanently replace your alternator with solar panels. It only works during the day, and when the sun is shining, and you're not sitting at a red light in the shade of a big old oak tree. kooks...

 

[drewk79]

I was searching my Electric bill yesterday and found they off Real Time Pricing for electricity.

I found a few articles on the subject and they say a 10% drop in peak consumption is common when this is implemented.

I looked back at some of the past high cost days and during the day prices would get to .20kWh but that night they would drop to just about $.02 kWh.

I have a large chest freezer maybe 30 cubic ft. We don't use it currently. I am thinking I could fill it full of water jugs and freeze the water at night then open it during the day to keep the house cool. Maybe install a fan.

I know there are systems that I can buy to do this but I have these parts what do you think?

Also being able to adjust our energy usage to low cost times of day is an immediate way to reduce peak demand immediately.

In my area it is $2.50 a month to be in the program they are using the old grid and they just change out your meter for free.( i guess that's what the $2.50 is for)

I am a home builder in the area and I live in a town with 700 people. I don't know anyone else in town using this and I talk to a lot of people. I guess the power company should get some credit for making it available but they get an F for putting it into effect.

 

[mheslep]

2. Sometimes it's difficult to tell when he's being sarcastic. Which would he prefer: Trams, bicycles, or electric cars?

I’ve looked up the performance figures for lots of electric vehicles –
they’re listed in this chapter’s end-notes – and they seem to be consistent
with this summary: electric vehicles can deliver transport at an energy cost
of roughly 15 kWh per 100 km. That’s five times better than our baseline
fossil-car, and significantly better than any hybrid cars. Hurray! To achieve
economical transport, we don’t have to huddle together in public transport
– we can still hurtle around, enjoying all the pleasures and freedoms of solo
travel, thanks to electric vehicles.

He's serious here. The drama is in keeping with his frustrated search for answers where the figures on the physics actually work out, and EVs are one place where they do.

 

[OmCheeto]

I was searching my Electric bill yesterday and found they off Real Time Pricing for electricity.

I found a few articles on the subject and they say a 10% drop in peak consumption is common when this is implemented.

I looked back at some of the past high cost days and during the day prices would get to .20kWh but that night they would drop to just about $.02 kWh.

Wow. That's a big difference. We pay $0.118/kWh peak and $0.037/kWh off peak. Though I'm not on metered service. But I would cut my bill at least in half if I were. At least 90% of my electric bill in devoted to heating. But I guess this is where Jevons paradox jumps in. Why get more efficient with your usage if you can get what you need for a third of the price by working the system. Up here in the northern latitudes, there are maybe 5 days a years when cooling your house is necessary.

I have a large chest freezer maybe 30 cubic ft. We don't use it currently. I am thinking I could fill it full of water jugs and freeze the water at night then open it during the day to keep the house cool. Maybe install a fan.

I know there are systems that I can buy to do this but I have these parts what do you think?

I've seen that on TV before. It does make sense.

Also being able to adjust our energy usage to low cost times of day is an immediate way to reduce peak demand immediately.

In my area it is $2.50 a month to be in the program they are using the old grid and they just change out your meter for free.( i guess that's what the $2.50 is for)

I am a home builder in the area and I live in a town with 700 people. I don't know anyone else in town using this and I talk to a lot of people. I guess the power company should get some credit for making it available but they get an F for putting it into effect.

If the utilities around here had a 10 to 1 difference between peak and non-peak and everyone were to utilize it, I think they'd go broke. I just don't see any logical reason to leave the heat on in my house when I'm not there. I suppose some people might want to come home after a long day at work to a cozy house. But watching that electric meter spin makes me go through all manner of hoops to get it to stop. A 6 m² solar thermal collector is first on my list of projects. I built a prototype 2 weeks ago out of 3 garden hoses, one solar panel, one 12vdc 500 gph bilge pump, and a 32 gallon rubbermaid trash can. It generated around 750 watts of thermal power with the pump consuming about 20 watts of power. The garden hoses were simply tossed onto a sunny spot on the roof. Away from the street of course. I don't want the neighbors thinking I'm some kind of mad scientist.

 

[mheslep]

... I don't want the neighbors thinking I'm some kind of mad scientist.

Too late, that horse has left the barn I expect.

Re your solar panels, may I ask: who's the manufacturer, when did you buy them, and how much?

 

[OmCheeto]

Too late, that horse has left the barn I expect.

Re your solar panels, may I ask: who's the manufacturer, when did you buy them, and how much?

They are made by Kyocera. My dad bought them, and they are date stamped 1991 thru 1993. When I researched their cost, they were $250. Though they may have cost more when originally purchased.

I found them to be so much fun to play with that I decided that if I hadn't inherited them, I should have bought at least one or two. Mobile energy is quite the convenience; see gasoline.

 

[mheslep]

MacKay his a nice video up that parallels his book. He has the gift for clear explanation.
Peddling past Sizewell nuclear plant:

If you don't like nuclear, for every Sizewell you want to get rid of you need an extra 2000 wind turbines

Sizewell is 1.1GW(e). Replace w/ 1.5MW turbines at 35% capacity factor, yep. And they'd still have to address storage / base load.

 

[mheslep]

I have revisited the battery and energy cost per mile claims for the EV / battery exchange proposal from the company http://www.betterplace.com" . The CEO stated a life cycle cost of 4-6 cents per mile for the battery. Now I believe that appears plausible, even likely. My calculations/assumptions:

$$\begin{array}{l|rrrr} \mbox{} & \mbox{EV sedan}\\ \mbox{} & \mbox{5-seat}\\ \hline \mbox{Vehicle Parameters}\\ \mbox{range(miles)}&100\\ \mbox{efficiency battery-to-wheel (kWh/mile)}&0.22\\ \hline \mbox{Battery parameters: }\\ \mbox{lifetime charge cycles}&3000\\ \mbox{lifetime range of pack}\\ \mbox{ 70 percent capacity (miles)}&210000\\ \mbox{pack capacity (kWh)}&22\\ \hline \mbox{Costs:}\\ \mbox{battery per kWh (dollars)}&400\\ \mbox{battery per pack (dollars 1000)}&8.8\\ \mbox{battery pack + spares (dollars 1000)}&11.5\\ \hline \mbox{Summary:}\\ \mbox{battery lifetime cost (cents/mi)}&5.5\\ \mbox{energy cost @9cents/kWh}&2.3\\ \mbox{total battery + energy cost (cents/mi)}&7.8\\ \hline \mbox{ICE vehicle fuel cost}\\ \mbox{@25MPG, @2.6 dollars /gal (dollars) }&10.5\\ \end{array}$$

Or 20% better than a comparable internal combustion vehicle. That's just battery & fuel costs. We may also expect savings on the EV only drive train/chassis versus the internal combustion comparable, that is a $2.5k electric motor displaces in the ICE:
Engine $1850, Trans $625, Exhaust system $460, Fuel tank/injection/other $860 = $3.8k
http://www.ge.com/battery/resources/pdf/DickonPinner.pdf (slide 23)Up thread Russ commented on this EV approach:

My only quibble with your calcs is with this one. We're a long way from electric vehicles being a total replacement for cars, so for right now and for the next several decades, the only people who would buy them are those who are highly conscious of fuel efficiency. And those are the people who today would buy a Prius at 40mpg or a Civic at 35...

The purchase price of a battery exchange capable EV with a chassis comparable to either a Prius or Civic should be substantially less. The Prius commands a premium because of its battery and hybrid drive train; the high mpg Euro Civic also does because of the more expensive diesel engine (Edit: and the Civic is smaller than Better Place's Renault)

edit: spreadsheet version of the above data attached

 

[mheslep]

Cost per km analysis from McKinsey, entire vehicle, model vehicle is a VW Golf. They show a BEV200km comparable in cost to a similar US Gas vehicle which is in agreement with my previous post. The same gas/diesel in Europe w/ the higher fuel taxes and combustion vehicle taxes is substantially more expensive than a BEV200.
http://www.ge.com/battery/resources/...ckonPinner.pdf, slide 24
They state in the notes that the battery model is depreciated separately from the vehicle, though they don't make clear how. A separate battery depreciate model is key for a battery exchange system. Above I used a battery life of cycles x the battery pack range * 70%. That's crude, as it doesn't reflect the battery shelf life which must come into play as the battery life in km/miles extends past ~150k/200k.

 

[mheslep]

Port of LA now using some electric trucks for its short haul work around the port. Full size 18 wheelers, 60000lb load, 40-60mi range. They went lead acid with the first ones, lithium on the next go round.
Mfn Fact Sheet
http://www.portoflosangeles.org/DOC/Electric_Truck_Fact_Sheet.pdf

Electric Truck
2 kilowatt hours of energy units per mile
Operation cost: 20 cents per mile
...
Diesel Truck with 5 miles-per-gallon*
Operation cost: 80 cents to 90 cents per mile
* The above energy consumption and energy cost comparisons are based on a 100% duty cycle, which diminishes in the diesel truck when the truck is idling. A common 50/50 duty cycle in a diesel truck, reflecting 50 percent idling time, would increase the diesel truck’s cost per kilowatt hour from .90 to $1.80

Video
https://www.youtube.com/watch?v=<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/0f1AlrG8gVU&color1=0xb1b1b1&color2=0xcfcfcf&hl=en&feature=player_embedded&fs=1"></param><param name="allowFullScreen" value="true"></param><param name="allowScriptAccess" value="always"></param><embed src="http://www.youtube.com/v/0f1AlrG8gVU&color1=0xb1b1b1&color2=0xcfcfcf&hl=en&feature=player_embedded&fs=1" type="application/x-shockwave-flash" allowfullscreen="true" allowScriptAccess="always" width="425" height="344"></embed></object>

 

[OmCheeto]

Did anyone read the article in the latest SciAm today regarding grassoline?

http://www.scientificamerican.com/article.cfm?id=grassoline-biofuels-beyond-corn"

I've not had a chance, and am running quite late.

 

[mheslep]

Did anyone read the article in the latest SciAm today regarding grassoline?

http://www.scientificamerican.com/article.cfm?id=grassoline-biofuels-beyond-corn"

I've not had a chance, and am running quite late.

Well this part is disappointing:

...[the author] is the founder of Anellotech, a biofuel startup

C'mon Sci American. That the explains the lack of any mention of the recent Science paper showing the biofuels are better used to produce electricity than gasoline.

 

[RonL]

Port of LA now using some electric trucks for its short haul work around the port. Full size 18 wheelers, 60000lb load, 40-60mi range. They went lead acid with the first ones, lithium on the next go round.
Mfn Fact Sheet
http://www.portoflosangeles.org/DOC/Electric_Truck_Fact_Sheet.pdf




Video
https://www.youtube.com/watch?v=<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/0f1AlrG8gVU&color1=0xb1b1b1&color2=0xcfcfcf&hl=en&feature=player_embedded&fs=1"></param><param name="allowFullScreen" value="true"></param><param name="allowScriptAccess" value="always"></param><embed src="http://www.youtube.com/v/0f1AlrG8gVU&color1=0xb1b1b1&color2=0xcfcfcf&hl=en&feature=player_embedded&fs=1" type="application/x-shockwave-flash" allowfullscreen="true" allowScriptAccess="always" width="425" height="344"></embed></object>

When I suggested this type of truck, someone said it was an asinine idea, Oh well not everyone thinks alike.
I'm still working on the lead acid batteries that last a lifetime. Even if energy density is compromised at 50% to 75%, would it be worthwhile?
I think so.

 

[mheslep]

When I suggested this type of truck, someone said it was an asinine idea, Oh well not everyone thinks alike.
I'm still working on the lead acid batteries that last a lifetime. Even if energy density is compromised at 50% to 75%, would it be worthwhile?
I think so.

Lead acid has two drawbacks here RonL, weight is one but the other is limited deep cycle lifetime. So its fine to build a few of these trucks with lead acid to see how they work out, but the batteries will quickly give it up. Even that's ok for the experiment - replace them, but it can't fly economically. A real working E-truck requires something else like Li-ion and thousands of deep cycles, which the Port of LA is doing as the sources above show.

 

[OmCheeto]

Well this part is disappointing:
C'mon Sci American. That the explains the lack of any mention of the recent Science paper showing the biofuels are better used to produce electricity than gasoline.

But it was very nice to see them mention that we could generate half of the country's motor car fuels from farm refuse.

I saw something that looked a lot like crude oil in the bottom of my bio-recycle bin last week, but I rinsed it out. I guess I should have taken it to work and had them do a spectrum analysis of the goop. Might be, one of my 20 weeds spontaneously decomposes into fuel. Now wouldn't that be something.

 

[drewk79]

Trains have been running diesel motors to power electric motors for years. Caterpillar is now building a D7 bulldozer that works on the same principal. No batteries. Raser has also built a H3 hummer using the same tech and claims 100 mpg. http://www.rasertech.com/media/videos/the-electric-h3

These technologies when mass implemented will only be one rung in a never ending search for energy independence.

O yeah I applied to switch over to Real Time Pricing on my elec bill. WooHooo!

 

[mheslep]

Energy Secretary Chu just announced big loans to three car companies for electric cars. Ford $5.9B, Nissan $1.6B, Tesla $465M. A US loan to a Japanese auto maker is eye raising, but the http://maps.google.com/maps?hl=en&tab=wl&q=Smyrna, Tennessee nissan" to be retooled is in Smyrna, Tennessee.
http://online.wsj.com/article/SB124573130607640647.html
http://blogs.wsj.com/environmentalc...-and-tesla-enjoy-a-big-day-for-electric-cars/

Rennault-Nissan has the deal with the electric infrastructure company Better Place to build battery switch capable cars, discussed above. Its not clear whether the vehicles coming from the Tn. plant will be compatible.

 

[mohd_adam]

For nuclear power plant 1000 MWe, it needs 24 tones of enriched uranium 3- 5%.
To get 24 tones of enriched uranium 3- 5% , we need 200 tones of uranium oxide 'yellow cake'. ( i hope correct of numbers are wrong )

in 2006 the world produce 39100 tones. If the world started depend on nuclear power, when uranium will run out !?
--------

 

[mheslep]

For nuclear power plant 1000 MWe, it needs 24 tones of enriched uranium 3- 5%.
To get 24 tones of enriched uranium 3- 5% , we need 200 tones of uranium oxide 'yellow cake'. ( i hope correct of numbers are wrong )

in 2006 the world produce 39100 tones. If the world started depend on nuclear power, when uranium will run out !?
--------

No.

Closed fuel cycles extend fuel supplies. The viability of the once-through
alternative in a global growth scenario depends upon the amount of uranium
resource that is available at economically attractive prices. We believe that the
world-wide supply of uranium ore is sufficient to fuel the deployment of 1000
reactors over the next half century and to maintain this level of deployment
over a 40 year lifetime of this fleet.

http://web.mit.edu/nuclearpower/pdf/nuclearpower-summary.pdf

And after the U runs out we can burn Th

 

[signerror]

For nuclear power plant 1000 MWe, it needs 24 tones of enriched uranium 3- 5%.
To get 24 tones of enriched uranium 3- 5% , we need 200 tones of uranium oxide 'yellow cake'. ( i hope correct of numbers are wrong )

in 2006 the world produce 39100 tones. If the world started depend on nuclear power, when uranium will run out !?
--------

The world uses about http://www.iea.org/Textbase/stats/balancetable.asp?COUNTRY_CODE=29 of thermal energy (1 ton oil equivalent = 42 GJ); one 1 GWe nuclear reactor produces about 3 GW of heat. So as an order-of-magnitude estimate, we would need about 5,000 one-gigawatt reactors.

If these were once-through reactors like ordinary light water reactors, we would need 5,000 * (200 tons/year) = 1 million tons uranium metal per year. If instead these were fast breeder reactors, we could use the U-238 (via U-238(n,gamma) Np-239 (,e-) Pu-239, which is fissile), and there is about 100 times more of that isotope than U-235 in nature. So, with closed fuel cycles, we would need 1/100th as much natural uranium, or 10,000 tons/year.

How much uranium we 'have' depends on what resources you consider accessible. According to the IAEA, there are an estimated 5 million tons of 'conventional' ore resources, and another 30 million tons unconventional, very low concentration resources in phosphate minerals (PO₄^-3). There is also about http://jolisfukyu.tokai-sc.jaea.go.jp/fukyu/mirai-en/2006/4_5.html tons of uranium salts dissolved in the oceans at 3 ppb, which appears to be feasible to extract.

I think the meaningful number here, since we were projecting centuries out, is the theoretical supply of ocean uranium, used in fast breeders: this is 5 billion tons / (10,000 tons/year) = 500,000 years at present world energy demand. The other, less meaningful permutations are - from the above numbers,

conventional reserves - 5 years
conventional reserves in FRs - 500 years
phosphate reserves - 30 years
phosphate reserves in FRs - 3,000 years
seawater reserves - 5,000 years
seawater reserves in FRs - 500,000 years

Hope this is helpful.

 

[mohd_adam]

thank you signerror , mheslep for the reply and the information..

 

[mheslep]

The world uses about http://www.iea.org/Textbase/stats/balancetable.asp?COUNTRY_CODE=29 of thermal energy (1 ton oil equivalent = 42 GJ); one 1 GWe nuclear reactor produces about 3 GW of heat. So as an order-of-magnitude estimate, we would need about 5,000 one-gigawatt reactors.

Well I don't know of any civilian reactor examples where reactor waste heat is used, so I think that must be ~15,000 one GW(e) reactors.

...
conventional reserves - 5 years
conventional reserves in FRs - 500 years
phosphate reserves - 30 years
phosphate reserves in FRs - 3,000 years
seawater reserves - 5,000 years
seawater reserves in FRs - 500,000 years

Hope this is helpful.

Plus another 1.5 million tons of Th worldwide

 

[signerror]

Well I don't know of any civilian reactor examples where reactor waste heat is used, so I think that must be ~15,000 one GW(e) reactors.

No, that's silly: it makes much more sense to compare like with like (thermal with thermal). For example: (nuclear electricity) EVs need to carry much less energy than petroleum cars, because they store electricity rather than thermal energy. So comparing oil joules with electricity joules would overestimate their electricity requirement by a huge factor. But if you compare oil joules with nuclear reactor heat joules, you get the right numbers - modulo differences in the efficiencies of the heat engines (internal combustion engine vs. steam turbine).

Also, direct use of nuclear reactor waste heat will probably be much more common in the future. For one thing, Gen IV reactors can finally reach temperatures high enough that waste heat can be used directly in industrial processes, like hydrogen production.

Plus another 1.5 million tons of Th worldwide

That's negligible compared to the U figures I showed.