Solar or Fusion?

[Kayra]

Fossil fuels will reign supreme for 3 to 4 decades;

then nuclear fission will catch up and dominate for 1 or 2 decades;

then ground solar (in combo with wind and geothermal) will take over for the rest of the century;

about 2100 CE, plus or minus a coupla decades, space solar will become a major player. The energy will be microwaved down to receiving stations in uninhabited areas (such as deserts) and used to feed the power grid.

 

I think Pyrotex has it pretty close.

I would say 2-3 decades for Fossil.

New nuclear reactors that will be used in China are amazing in their design. Cheap construction, minimal waste, small footprint (2 flatbed trucks for a 2oo MW plant. not including cooling tower.), and so completely safe that they can not melt down under any condition short of being hit with a nuclear device. With this type of tech, they will likely take over as a main source of power generation after fossil for a short while. It will take 30 years simply because of the massive inertia of the current system (lots of infrastructure) combined with the distrust of nuclear systems and lack of good batteries for cars and grid.

 

Even with that though, in 30 years I expect ubiquitous, cheap, and near perfect ground solar combined with similar tech for batteries to pretty much meet our needs easily into the next century. Throw in new concepts like using the cars plugged into the grid as a massive storage device and it will all come together quite nicely.

 

Beyond that would be space based solar with direct transmission of the power in mechanical form through a looped space tether (100% power transfer efficiency and a cheap means to orbit.)

[Kayra]

In the "did you know" department, any power generation system that involves steam throws out 35-45% of the heat energy (reconstituting water from steam) to generate power. This includes nuclear, coal, geothermal, solar collectors that use thermal component of the sun, etc.

 

 

The second law rules us all :hihi:

[Moontanman]

Time for a new poll....

 

"Commercially viable" Fusion Power has for the past 50 years been endlessly "available within the next 10 years." Its endlessly waiting for a breakthrough to make it "practical."

 

Solar power has grown slowly as technology as incremental improvements in both photo-voltaic and direct-heating techniques have improved.

 

So this poll is basically the following question:

 

Which will happen first? "Solar will provide the majority of electrical power," or "The first commercially profitable Fusion power plant will go on line." There's a cop out option that says "Fossil fuels will continue to provide the majority of power" (at least as long as humans manage to survive!). Oh and for the heck of it, "Some other new power source will become number one" but if you pick this one you have to say what you think it its.

 

For sticklers: "provide power" is referring specifically to providing land-line-delivered electrical power to homes and/or businesses.

 

Vote! If you're Australian, its the law! :hihi:

Buffy

 

Conventional fusion is a pipe dream, it emits as many neutrons as fission power plants and would have to abandoned for centuries after a few years of operation because of all the nuetrons released by conventional fusion would make everythjing inside the plant highly radioactive, sound familiar?

There is a possible alternative that produces no radioactive waste at all it's called anuetronic fusion and uses helium three instead of hydrogen or duetrium or tritium. When you fuse helium three it only produces electromagnetic radiation which cannot make anything else radioactive and can be turned directly into electricity without the heated water or turbines used by todays power plants.

In the mean time we need to develope nuclear reactors that actually run on what we consider radioactive waste. they use it up until it's a small fraction of what it was and it is very short lived radio isotopes that are left over that don't have to be stored for an eternity.

 

Michael

[Boerseun]

Of all the options, I guess solar will top the list, if we can somehow store the power for night usage. Power loss over transmission lines is too big to make a global solar power grid (with some part of it always facing sunshine) a practical reality.

 

That being said, I don't think any of the options will really provide us with our required juice by 2100. Take a look at scalable modular pebble-bed nuclear reactors, if you want to see the future of Earth's energy supply. And then invest heavily in Australian uranium mining companies - the Outback'll be the Middle East of the 21st century, me laddies...

[Moontanman]

Of all the options, I guess solar will top the list, if we can somehow store the power for night usage. Power loss over transmission lines is too big to make a global solar power grid (with some part of it always facing sunshine) a practical reality.

 

That being said, I don't think any of the options will really provide us with our required juice by 2100. Take a look at scalable modular pebble-bed nuclear reactors, if you want to see the future of Earth's energy supply. And then invest heavily in Australian uranium mining companies - the Outback'll be the Middle East of the 21st century, me laddies...

 

 

there is enough nuclear waste already in storage to supply power for decades if not centuries. but the real money will be in thorium, thorium can be used in reactors and the by products used over and over just like uranium but the good part is that none of the by products of thourium reactors can be used to make a nuclear weapon.

 

Michael

[Pyrotex]

It's very hard to make electricity with nuclear waste. It just doesn't get HOT enough. The reason is, bombarding the waste with neutrons doesn't cause fission. Thorium, on the other hand, will fission if bombarded with neutrons.

 

That's why nuclear waste is called... [ahem] "nuclear waste". :P

[Moontanman]

It's very hard to make electricity with nuclear waste. It just doesn't get HOT enough. The reason is, bombarding the waste with neutrons doesn't cause fission. Thorium, on the other hand, will fission if bombarded with neutrons.

 

That's why nuclear waste is called... [ahem] "nuclear waste". :P

 

You are "ahem" not thinking outside the box. It takes something other that 1940's tecnology to make a reactor that uses waste rods as fuel. You have to have new types of reactors that run very hot and use liquid lead or other metals as a coolants. They are even safer than the reactors we use becuase if the cooling system fails the reacton stops. Fast breeder reactors will also burn "waste rods" France has the stones to do it, everyone else is too squemish to even look at the concept.

 

Michael

[Jay-qu]

Of all the options, I guess solar will top the list, if we can somehow store the power for night usage. Power loss over transmission lines is too big to make a global solar power grid (with some part of it always facing sunshine) a practical reality.

 

That being said, I don't think any of the options will really provide us with our required juice by 2100. Take a look at scalable modular pebble-bed nuclear reactors, if you want to see the future of Earth's energy supply. And then invest heavily in Australian uranium mining companies - the Outback'll be the Middle East of the 21st century, me laddies...

Sorry I dont think so, we just dont have enough Uranium there to do it. I looked up the figures earlier in the year and if we solely depended on nuclear power our reserves wouldnt last very long at all..

 

I understand PBMR are more efficient, do you have a number on how much more efficient they are?

[OldBill]

Re "Everyone else is too squemish......" Not true. The Russians have always had an affinity for 'fast' reactors (including FBR's) because of their effectiveness with lower-enriched, mixed oxide fuels. However, in fairness we need to point out that the four graphite-moderated Chernobyl reactors were not in that category.

 

Addressing the question at hand, the most likely near-term successor to current energy resources will come from continuing breakthroughs in electrolysis technology and hydrogen fuel cell refinement.

[Moontanman]

Re "Everyone else is too squemish......" Not true. The Russians have always had an affinity for 'fast' reactors (including FBR's) because of their effectiveness with lower-enriched, mixed oxide fuels. However, in fairness we need to point out that the four graphite-moderated Chernobyl reactors were not in that category.

 

Addressing the question at hand, the most likely near-term successor to current energy resources will come from continuing breakthroughs in electrolysis technology and hydrogen fuel cell refinement.

 

Yes, but where will the energy come from for the electrolysis? solar? doubtful as fusion. Modern nuclear reactors are the only real possibilities so far. Unfortunately no one seems to be willing to actually build a truely modern nuclear reactor. Maybe if we manage to mine the moon for helium three we will learn to fuse it and actually take the next step in power generation and bypass all the 18th century turbines and such.

 

Michael

[Moontanman]

Sorry I dont think so, we just dont have enough Uranium there to do it. I looked up the figures earlier in the year and if we solely depended on nuclear power our reserves wouldnt last very long at all..

 

I understand PBMR are more efficient, do you have a number on how much more efficient they are?

 

Did you figure in thorium deposites in that estimate? Or reactors that burn waste fuel rods?

 

Michael

[Jay-qu]

No, it was purely a uranium estimate. I looked up some figures and they seem to vary quite a bit.. the wiki on uranium puts Earths mineable deposits at 4.7 million tonnes - while another 35million tonnes is in mineral deposits. It is likely that better methods of finding and extracting Uranium will make more lower grade deposits available for mining in the future.

 

It is unclear what this 4.7 million tonnes is of. High grade Uranium ore is only around 2% Uranium, available mostly as uranium oxides. But then you cant forget that only .71% of this uranium is fissionable U-235. The Uranium must be enriched to around 5% for use in reactors.

 

So these figures boil down to the worlds reactors needing 67,000 tonnes of Uranium ore per year. This produces an output ~370GW. So at this rate the reserves would last about 70 years. Couple that with the fact that Nuclear is only powering 15% of the worlds growing electricity needs and you come to the conclusion that we cant rely on Uranium as the dominant fuel for nuclear power. That is unless we can find better ways of extracting it (ideally we should learn to extract it from sea water :hal_jackolantern:).

 

On another not, it is estimated that Thorium is about 3 times more abundant in the Earths crust.

[CraigD]

Sorry I dont think so, we just dont have enough Uranium there to do it. I looked up the figures earlier in the year and if we solely depended on nuclear power our reserves wouldnt last very long at all.

Mine calculations suggest that, while by no means promising an endless supply of energy, the fission of uranium is sufficient for 20 to 2000 years of the world’s current total power.

 

Here are my rough figures:

• Total amount of elemental uranium:
  • In Earth’s crust: [math]10^17 \,\mbox{kg}[/math]
    
  • In seawater: [math]10^13 \,\mbox{kg}[/math]
    
  • In known ore reserves: [math]10^10 \,\mbox{kg}[/math]
    
  • In expected ore reserves: [math]10^11 \,\mbox{kg}[/math]
    

  [*]Energy yield with present-day reactor technology: [math]10^11 \,\mbox{J/kg}[/math]

  [*]Current total human power needs: [math]1.5 \times 10^13 \,\mbox{W}[/math]

So, duration that Uranium fission can supply worlds current total power needs:

• 20 years from known reserves
  
• 200 years from expected reserves
  
• 2000 years if large-scale seawater extraction feasible
  

(sources: Uranium - Wikipedia, the free encyclopedia; World energy resources and consumption - Wikipedia, the free encyclopedia)

 

Note:

• The above figures include all of the world’s power needs, not just electrical, so the projections assume all future power ultimately supplied electrically
  
• Energy and other costs of reactor construction, fuel processing, etc, are ignored
  
• Population growth, which is difficult to predict, could dramatically reduce the lifetime of fission power as a world energy source.
  

… So at this rate the reserves would last about 70 years.

This agrees roughly with my calculations 200 year figure

…That is unless we can find better ways of extracting it (ideally we should learn to extract it from sea water :)).

This also agrees. Efficient seawater extraction could, by my calculation, increase the total amount of uranium fission energy available by about a factor of 4

On another not, it is estimated that Thorium is about 3 times more abundant in the Earths crust.

I agree. So potentially, Thorium might provide about 2 times the amount of energy as ore-derived uranium – 140 to 400 years at present day power.

 

I think we’re in agreement that, while promising in the short term, nuclear fission power is only a temporary solution.

 

As best I’ve been able to determine, the only truly long term energy source is solar radiation. In practical terms, when one accounts for factors normally taken as given, such as the average temperature of the Earth’s lower atmosphere, and energy from plant material, such as food and fossil fuel (85% of our current engineering power comes from fossil fuels, which are essentially plant material) our civilization is already nearly 100% solar.

 

Thinking ahead, I believe that our civilization must ultimately use many powers of 10 times more power than it currently does. The only way I can imagine this happening is via space-based solar collectors. This post summarizes my vision of the long-term energy future of humankind.

[Moontanman]

No, it was purely a uranium estimate. I looked up some figures and they seem to vary quite a bit.. the wiki on uranium puts Earths mineable deposits at 4.7 million tonnes - while another 35million tonnes is in mineral deposits. It is likely that better methods of finding and extracting Uranium will make more lower grade deposits available for mining in the future.

 

It is unclear what this 4.7 million tonnes is of. High grade Uranium ore is only around 2% Uranium, available mostly as uranium oxides. But then you cant forget that only .71% of this uranium is fissionable U-235. The Uranium must be enriched to around 5% for use in reactors.

 

So these figures boil down to the worlds reactors needing 67,000 tonnes of Uranium ore per year. This produces an output ~370GW. So at this rate the reserves would last about 70 years. Couple that with the fact that Nuclear is only powering 15% of the worlds growing electricity needs and you come to the conclusion that we cant rely on Uranium as the dominant fuel for nuclear power. That is unless we can find better ways of extracting it (ideally we should learn to extract it from sea water :evil:).

 

On another not, it is estimated that Thorium is about 3 times more abundant in the Earths crust.

 

Did you include reactors that can burn used fuel rods of regular reactors and get several times as much energy out of them than just the U 235. Anyway Helium three fusion is the only real unlimited power source but it's all in the regolith of the moon and probably the asteroids. Far more efficient and the energy released can be turned directly into electricity without the turbines and generators of regular power plants. Conceivably helium three fusion could power a car or have your own home reactor about the size of a whole house air conditioner since no neutron radiation is produced. But helium three is very rare on the earth. We have to go to the moon to obtain it. It has been calculated the amount of helium three that could be put in the cargo hold of the space shuttle could power the entire energy needs of the US for a year, and no radioactive waste! there is also a concevable type if fission power that produces no partical radiation but I am not really familiar with it or it's viability.

 

Michael

[Jay-qu]

The ideas your propose are very fanciful Michael, do you have a source of that info that I could look at? :)

 

I dont see how Helium3 fusion can be used to directly convert energy to electricity without the use of turbines..

[Moontanman]

The ideas your propose are very fanciful Michael, do you have a source of that info that I could look at? :)

 

I dont see how Helium3 fusion can be used to directly convert energy to electricity without the use of turbines..

 

http://hypography.com/forums/community-polls/13131-solar-fusion-new-post.html

.

Helium 3 fusion gives off no hi energy particles like neutrons so it cannot make anything else radioactive. The process does give off electromagnetic radiation which can be directly turned into electricity by photovoltaic cells. I tried to send some links last night, not much is available due to lack of research in favor of conventional deuterium/tritium fusion which does give off neutrons among other things and would make the reactor so radioactive it would have to be abandoned in a few decades and allowed to sit for centuries before it was safe. I tried to send some links last night but I had a cold and feeling to bad to do it right. There is also a process called aneutronic fission but I am not familiar with that.

 

aneutronic fusion - Google Search

 

anuetronic fission - Google Search

 

Michael

[Jay-qu]

Im not sure how you managed to do it, but that post links to itself :)

 

Aneutronic fusion just means it releases most of its energy (>99%) in forms other than that of neutrons.

 

Even if all the energy produced by this fusion was electromagnetic energy and it was all captured by appropriate photovoltaic cells, they themselves only yield 10-15% efficiency..