Is the suns energy enough?

[foges]

The title may be slightly misleading, but this is what I'm wondering about: I watched a documentary yesterday called "Home" and they stated the following: "In one minute the sun delivers enough energy to the earth to feed all of humanities energy requirements for a whole year". Im not sure what they meant by all of humanity, but this statement was supposed to sound shocking as if that were some crazy amount of energy... Now 24*365 = 8760, that would mean to live off just solar energy we would have to cover for example app. 1/9000'th of the whole planet earth with 100% efficient solar panels (assuming the earth never spun and those solar panels were constantly being exposed to the sun) . That doesn't sound very plausible to me. It sounds to me like we would have to have to cut down quite a bit on our energy consumption to be able to live just off renewable fuels...

What am I missing here?

 

[Cogman]

Nothing, welcome to the realization of how worthless solar is for a general power source. though, your calculation is off. it should be 24*60*365=525600, so 1/525600th of the earth would have to be covered in 100% efficient constantly exposed to sun light solar cells. If we wanted a more realistic covering number, (factoring power loss for transmission) I would put it at ~10% efficient using todays best tech (~30%, /2 for daily exposure, and minus a little for other inefficiencies.) effectively increasing the need to 10x, giving us 1/52560 of the earth needing to be covered. Which translates to 9704 km^2 or 3746 square miles.

 

[Juncar]

Well if we can even get a fraction of that coverage with more efficient solar panels, then that will help with the lack of energy. Though its probably unlikely and not secure to base your entire energy production on solar energy.

 

[Cogman]

Well if we can even get a fraction of that coverage with more efficient solar panels, then that will help with the lack of energy. Though its probably unlikely and not secure to base your entire energy production on solar energy.

1 square mile of solar cells (a very small fraction of the required) is HUGE. Costs billions, and without being subsidized, will never earn back the money that it costs to be built in the first place. (remember, it isn't just solar panels, but DC->ac converters ect). The cells don't last forever either. They have a half life of ~10 years IIRC. and must constantly be maintained (removing dirt, bird droppings, ect). couple that with mining costs and materials manufacturing and you have a really expensive, dirty, power generation method.

Even at near 100% efficiency, those problems will still exist. Compare that to just about any other power generation technology (Except for wind, which is somewhat worse the solar in costs ect) and all the sudden putting any research into solar makes almost no sense.

Want clean? For the same sq mile you would have filled with solar panels, you could fill it with 14,529 years worth of nuclear waste (dig it down a bit, and you can add a few more 0's onto there). And that is antiquated 60-70's fission tech we use now. Employ enrichment and fuel reuse, and you could easily extend that number by a few thousand years. And those are techs that exist today. (the footprints of these reactors are hardly worth mentioning compared to that of solar panels)

Viable fusion reactors could provide humanity with power for the rest of their existence, with its waste materials being mostly harmless.

 

[Lemon law]

Post deleted.

 

[William Gaatjes]

1 square mile of solar cells (a very small fraction of the required) is HUGE. Costs billions, and without being subsidized, will never earn back the money that it costs to be built in the first place. (remember, it isn't just solar panels, but DC->ac converters ect). The cells don't last forever either. They have a half life of ~10 years IIRC. and must constantly be maintained (removing dirt, bird droppings, ect). couple that with mining costs and materials manufacturing and you have a really expensive, dirty, power generation method.

Even at near 100% efficiency, those problems will still exist. Compare that to just about any other power generation technology (Except for wind, which is somewhat worse the solar in costs ect) and all the sudden putting any research into solar makes almost no sense.

Want clean? For the same sq mile you would have filled with solar panels, you could fill it with 14,529 years worth of nuclear waste (dig it down a bit, and you can add a few more 0's onto there). And that is antiquated 60-70's fission tech we use now. Employ enrichment and fuel reuse, and you could easily extend that number by a few thousand years. And those are techs that exist today. (the footprints of these reactors are hardly worth mentioning compared to that of solar panels)

Viable fusion reactors could provide humanity with power for the rest of their existence, with its waste materials being mostly harmless.

Very true, even now we have the means to convert radioactive waste to light radioactive material. But it cost a lot of money. The technology exists, but is expensive. There is even a theory that most of the uranium ore is processed by uranium eating bacteria.

it is not this link but it provides some information.
http://findarticles.com/p/articles/mi_m1200/is_n7_v142/ai_12548027/

Now what i would like to know, is if these bacteria actually use the radiation itself or at least use the isotopes for certain reactions. That is what find interesting. I mean chlorophyll used by plants for example absorbs some of the electromagnetic spectrum of sunlight. I would not be surprised if bacteria would exist that use an even more energetic part of the electromagnetic spectrum.
Anyway, when there is more understood about the photo electric effect, then the idea behind solar cells will be viable.

For clarification , solar cells use the Photovoltaic effect.

 

[Juncar]

1 square mile of solar cells (a very small fraction of the required) is HUGE. Costs billions, and without being subsidized, will never earn back the money that it costs to be built in the first place. (remember, it isn't just solar panels, but DC->ac converters ect). The cells don't last forever either. They have a half life of ~10 years IIRC. and must constantly be maintained (removing dirt, bird droppings, ect). couple that with mining costs and materials manufacturing and you have a really expensive, dirty, power generation method.

Even at near 100% efficiency, those problems will still exist. Compare that to just about any other power generation technology (Except for wind, which is somewhat worse the solar in costs ect) and all the sudden putting any research into solar makes almost no sense.

Want clean? For the same sq mile you would have filled with solar panels, you could fill it with 14,529 years worth of nuclear waste (dig it down a bit, and you can add a few more 0's onto there). And that is antiquated 60-70's fission tech we use now. Employ enrichment and fuel reuse, and you could easily extend that number by a few thousand years. And those are techs that exist today. (the footprints of these reactors are hardly worth mentioning compared to that of solar panels)

Viable fusion reactors could provide humanity with power for the rest of their existence, with its waste materials being mostly harmless.

Yes that is correct with current levels of technology, a square mile of solar panel will cost around 1-2 billion dollars depending on the quality and efficiency. Though I doubt manufacturing them is worse than building nuclear plants. Solar panels are largely made of silicon, not much worse than materials used to manufacture other semiconductors. Though it will require frames and chemicals, storage batteries being the main polluter. There are massive amounts of money being spent on researching better battery technologies so we will see what happens in the future.

Nuclear plants probably are worse for the environment due to all the cements and steels used. The materials for nuclear power plants such as ingredients for cements and uranium must still be quarried or mined. I do prefer nuclear over coal power plants but nuclear is not cheap. It cost several billions to construct, several hundred millions to decommission and you still have to pay for the fuel, maintenance and etc, which puts doubt to whether it is cheaper than solar panels.

Nuclear power plants are centralized while solar panels are mainly distributed, its a different form of energy production management. Current grid system are not built for distributed energy production. Solar panels are merely for supplementing existing power generation, I doubt it will take over anytime soon, but it does not mean that we should not fund research for more efficient and cheaper to manufacture solar panels. Energy production based on fusion is a myth, there are no credible peer reviewed research that was able to in anyway produce fusion in laboratory settings, much less real world scenarios. Also not every country on Earth is able to have or maintain nuclear power plants for many reasons.

 

[Red Squirrel]

Havesting the heat is better then light. Get enough mirrors to point to a sterling engine and you can generate a decent amount of power using much less space then solar panels.

 

[Juncar]

Havesting the heat is better then light. Get enough mirrors to point to a sterling engine and you can generate a decent amount of power using much less space then solar panels.

Stirling engines with mirrors pointed to them is comparable in efficiency to solar panels with mirrors pointed to them. The Stirling engines in that case has the advantage of price at this point with the current efficiency of solar panels.

 

[Elias824]

Havesting the heat is better then light. Get enough mirrors to point to a sterling engine and you can generate a decent amount of power using much less space then solar panels.

Isnt that the technique they use in modern solar farms? its not just miles and miles of panels.

 

[William Gaatjes]

Stirling engines with mirrors pointed to them is comparable in efficiency to solar panels with mirrors pointed to them. The Stirling engines in that case has the advantage of price at this point with the current efficiency of solar panels.

Would it not be great if someone could design a 2 step hydrogen fuel cell where the intense heat from a parabolic mirror could be used together with a catalyst to separate the hydrogen from the oxygen found in water ? And then use the separated hydrogen and oxygen again in the fuel cell to generate electricity. This way electricity can be stored for the night. We just have to figure out how to use intense heat or intense uv radiation together with a catalyst to split H2O into loose components. Well, someone specialized would be more capable then me... It is not my field, but i like generating idea's. :biggrin:

 

[Juncar]

I think this link answer it for you

http://web.mit.edu/newsoffice/2008/oxygen-0731.html

 

[William Gaatjes]

I think this link answer it for you

http://web.mit.edu/newsoffice/2008/oxygen-0731.html

I think it is for all of us...

Thank you...

May i be so bold to write that great minds think alike ?
^_^

EDIT:
Unfortunately, they still need solar cells. I was thinking to leave the solar cells out of it. Use the power of parabolic mirrors directly. I once read that many chemical processes double in speed with every quantified increase in temperature.

 

[Juncar]

Well this thing runs by running electricity through the catalyst, so it does not have to be produced using solar panels. Yes many chemical reactions increase in rate with increase in temperature, because more thermal energy means that the particles are more likely to collide with each other with more energy so it increases the chance of that chemical reaction occurring. Catalysts simply decreases the threshold energy needed for the reaction to occur. If the thermal energy directed from the mirrors are enough then maybe, but for splitting small molecules such as water, probably not. Which is why electricity is more practical.

 

[William Gaatjes]

I think you are right. If i am not mistaken, most if not all chemical processes are electric of nature. Perhaps the phenomenon pyroelectricity can be put to use...

Maybe a catalyst based on this material or something a like.

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

 

[Juncar]

I'm not sure what you mean by electric of nature. Pyroelectricity is still new and I haven't seen any possible commercial products for them yet. We'll will see, but catalysts based on those materials aren't the ones that were able to easily split water into oxygen and hydrogen.

 

[William Gaatjes]

I'm not sure what you mean by electric of nature. Pyroelectricity is still new and I haven't seen any possible commercial products for them yet. We'll will see, but catalysts based on those materials aren't the ones that were able to easily split water into oxygen and hydrogen.

Is it not always giving up electrons or sharing them ? A covalent bond and an ionic bond ? Or filling up vacancies for electrons ? I never had chemistry :'( but i have some books.

 

[The Boston Dangler]

the phenomena known as "food" and "fresh water" are largely based on solar power.

 

[DrPizza]

There is even a theory that most of the uranium ore is processed by uranium eating bacteria.

Sounds like absolute nonsense to me, although I'm not exactly sure what you're talking about. Nothing any bacteria does to a Uranium atom is going to change it to something else. Nothing any bacteria does to a Uranium atom is going to affect that atom's half life. Nothing a bacteria does to a pile of Uranium is going to affect the radioactivity of that pile.

Re: Fusion. Fusion has been done successfully in labs quite often. It's not hard to do at all. There are kids who have built fusion reactors as science fair projects. What *hasn't* been done is having a positive energy balance at the end of the reaction. i.e. no one has gotten out more energy than they've put into it.

Re: hydrogen production. If I'm not mistaken, the majority of hydrogen is produced by a higher temperature process: steam reforming with methane gas. NOT by using electricity. Steam reforming with methane is more efficient than using electricity with water.

 

[William Gaatjes]

I'm not sure what you mean by electric of nature. Pyroelectricity is still new and I haven't seen any possible commercial products for them yet. We'll will see, but catalysts based on those materials aren't the ones that were able to easily split water into oxygen and hydrogen.

Well i was thinking about it, If you could heat up water hot enough to turn into plasma. But that is not going to work because of the extremely high temperatures of more then 10.000 degrees celcius. But a combination of intense heat of a few hundred degrees celcius and electricity could do the trick. Turn the water into gas and use an pyro electric catalyst that generates the required local electric field to rip the h2o molecule apart. Well, that was my idea. But i do not know if it is feasible yet. It has potential to be a nice closed cycle though.... Because the waste product which is water from the fuel cell can be used again.

Just out of curiousity :
Is it even possible to separate the ions and electrons in a plasma of one element ? How about is it possible to separate the ions and electrons in a multi element plasma ?

 

[William Gaatjes]

Sounds like absolute nonsense to me, although I'm not exactly sure what you're talking about. Nothing any bacteria does to a Uranium atom is going to change it to something else. Nothing any bacteria does to a Uranium atom is going to affect that atom's half life. Nothing a bacteria does to a pile of Uranium is going to affect the radioactivity of that pile.

I cannot find it anymore but this is what i had so far.
http://www.washingtonpost.com/wp-dyn/content/article/2006/10/19/AR2006101901671.html

Perhaps this bacteria can learn us some new tricks.

Re: Fusion. Fusion has been done successfully in labs quite often. It's not hard to do at all. There are kids who have built fusion reactors as science fair projects. What *hasn't* been done is having a positive energy balance at the end of the reaction. i.e. no one has gotten out more energy than they've put into it.

I once put a link in this section of the forum to a google video about the polywell fusion generator from Robert W. Bussard and his team at the time. Unfortunately they never got the resources to do a big scale test. But what he explained that on the day of cleaning out the lab, they discovered there was a net gain of energy . Unfortunately it is now the late Mr Bussard and it seems the late polywell as well...

Re: hydrogen production. If I'm not mistaken, the majority of hydrogen is produced by a higher temperature process: steam reforming with methane gas. NOT by using electricity. Steam reforming with methane is more efficient than using electricity with water.

Why is this ?

 

[DominionSeraph]

Holy crap. The amount of solar energy that falls on the entire US is only 4200 times its electrical production.
I'm scared to figure in automobile usage.

 

[Juncar]

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

More cost effective because its a by-product for another important process that is done on mass scale. Regarding the fusion, yea my mistake, I should have specified that there are no credible experimentation that created self-sustainable fusion yet. This is still in the realms of scientists, not for engineers yet

For the MIT article I posted above, it is about increasing the efficiency of energy storage for renewable power generation like wind or solar where it is not reliable all the time. We'll have to wait and see how much would this new storage method cost.

 

[DrPizza]

Gaatjes, perhaps you should read the article, and it's pretty much exactly what I expected. The bacteria do not use, nor capture the radiation directly.

First, water molecules -- H2O -- are split by radioactive particles. The result is hydrogen, oxygen and hydrogen peroxide. The latter two substances then attack the mineral pyrite (also known as iron sulfide or "fool's gold"), making sulfate through a process called oxidation.
The bacteria then uses the hydrogen to turn the sulfate back to sulfide, a process known as reduction. In doing so, it captures some of the energy in the sulfate's chemical bonds, which it uses to make ATP, the molecule that is the universal coin of energy exchange in living things.

What the bacteria are "eating" is little different than those deep in the sea in the anaerobic environment surrounding volcanic vents. It's only that radiation provides the energy for the chemical reactions that result in chemicals with more energy. Any suggestion that bacteria are capable of nuclear reactions, rather than simple chemical reactions, is absolutely ludicrous.

Also, speaking of reading better, steam reforming is not a by product of another industrial process, as you suggested in the previous post. Steam reforming is simply a more efficient process. (Followed on wikipedia by "hydrogen is ALSO produced as a byproduct... " I'm not sure how you're interpreting that to mean the steam reforming process is a byproduct.

 

[notposting]

Saw this thread from the main forum view and this came to mind: crank the volume for it though