Why we have to start living more like the Na'vi now

[Human No More]

Originally Posted by Clarke

You're aware that a full-size Dyson swarm takes a couple of thousand years to build, right?

Yes, I am. I am actually not stupid, and was specifically pointing that out as it being the only way to make solar practical, if you had read my actual post.

[Tsyal Makto]

Lots of big-oil/coal talking points being tossed around in this thread.

Anyway, looks like space-based solar is not as far away as people seem to imagine.

Orbital solar power plants touted for energy needs | Sci-tech | DAWN.COM

[Human No More]

Not bad... but convincing governments to fund it is the harder part.

[Tsyal Makto]

Ideally I would say all it would take is a good round at the ballot box, but given how many lobbyists are running around in the world...I doubt that approach would work.

[Theorist]

It's sad that if we took just a tenth of the U.S. military budget, we would easily have the money to get this going

[Fkeu'itan]

Looks like if we need environmentally non-intrusive means of power production to work... All we need to do is to simply reduce demand.

[Clarke]

You mean nuclear, for instance? The main obstacle to that is actually NIMBY.

[Aquaplant]

Originally Posted by Fkeu'itan

Looks like if we need environmentally non-intrusive means of power production to work... All we need to do is to simply reduce demand.

And this is easily explained to all the people who think electricity just comes out of the wall socket.

Originally Posted by Clarke

You mean nuclear, for instance? The main obstacle to that is actually NIMBY.

Nuclear power is clean, but the waste is not, so it's rather difficult equation. We need a cheap space elevator to dump all the nuclear waste into the sun. Though I wonder would that cause some stability issues over long term? Dumping fission waste into fusion doesn't really sound like the best idea... Then again on paper that makes perfect sense, if only the fission would be much smaller in scale that it is with uranium.

And they wonder why experimental scientists hate theoretical scientists...

[auroraglacialis]

Originally Posted by Clarke

Approximately 1000W/m^2, so 500W/m^2 when you take night into account. [...] It's also, AFAIK, not a lot compared to nuclear or even coal.

Average electricity consumption per capita is 700W in the EU, a bit above 800 Watts in Germany and Japan. Averaged annual (!) solar radiation (that includes nights and cloudy days) is about 1000W/m² in Germany, a lot higher in southern european regions, less in the North. Photovoltaics are on average about 12% efficient. So Photovoltaic area to cover the energy needs of an average German citizen at 800W would need about 10m² of solar cells, that is about 3x3m. Solar thermal conversion units (concentrate ligth to heat a fluid to drive a conventional thermal power generator) have efficiencies comparable to that of other thermal power plants, about 30-40%. They also do not require as much toxic processes as other solar options because they are basically conventional thermal machines in combination with mirrors. Applied to a small scale, this would translate into about 3m² per Person. That is a dish of about 2m in diameter! A problem of course is intermittency, so that machine would probably produce 3000W one day and zero the next night. This means heat or electricity has to be stored and used when it is available. This is also why the general idea is to have an "energy mix" with for example biogas jumping in to fill the gaps.

There is no need to put these things into orbit or on Mercury - there is plenty of sun here. Maybe not enough for everyone to live wastefully or for everyone to have a personal electric helicopter or something, but d'oh - I guess we can for now live without that.

Originally Posted by Human No More

It's perfectly possible if we can build a Dyson shell...[solar energy]is THE most expensive form of energy available, as well as creating complete environmental destruction in areas where resources are processed for it

Lets leave out SciFi stuff for now, can we? We can talk about Dyson spheres or fusion reacors when they are technologically feasible and economically viable. Re the environmental destruction - I agree that this is the case. As it is for ALL energy production systems. There are basically no large scale options that go around this because electricity and high technology itself needs these minerals and processing. No matter if that is any kind of electricity generators (needs magnets), electronics (REEs, copper, gold) or appliances (copper, plastics, special metals). There are some that pollute less, one of them is hydrothermal where it exists, another is solar thermal.

Originally Posted by Aquaplant

That is like the most annoying thing with electricity ever. I can haz room temperature superconductor plz?

Ah, lets hope no stupid romantic native people are sitting on that then

Originally Posted by Fkeu'itan

Looks like if we need environmentally non-intrusive means of power production to work... All we need to do is to simply reduce demand.

Agreed!

Originally Posted by Clarke

You mean nuclear, for instance? The main obstacle to that is actually NIMBY.

And is NIMBY such a strange idea? Seriously I think we need more NIMBY everywhere, because people should not have to put up with having some stuff happening in their vicinity that supposedly is to the better of the nation or mankind. Who are we to say that some people living in some place are supposed to take the risk or pollution while others take the benefit. I am sure you (Clarke and HNM) would happily like to live in the shadow of a nuclear power plant and enjoy the view, but many people do not and to tell them they are wrong and just put the stuff there - thats not working.

Originally Posted by Aquaplant

Nuclear power is clean, but the waste is not, so it's rather difficult equation. We need a cheap space elevator to dump all the nuclear waste into the sun. Though I wonder would that cause some stability issues over long term?

I doubt the sun would care about that scale. But again - SciFi terrain....
Nuclear power is clean exactly at one point - when the plant is in operation and is working without major failures. The mining and processing of the fuel, the handling, processing and storage of the waste and the deconstruction of the contaminated plants themselves are all not exactly clean.

[Moco Loco]

Originally Posted by Aquaplant

We need a cheap space elevator to dump all the nuclear waste into the sun. Though I wonder would that cause some stability issues over long term? Dumping fission waste into fusion doesn't really sound like the best idea...

Due to the scale of the sun, I hardly think it would cause issues of any kind I'd be more concerned about if something would go wrong on its way away from Earth

[Aquaplant]

Originally Posted by auroraglacialis

Ah, lets hope no stupid romantic native people are sitting on that then

At least they are sitting on something more useful than we are, but then again it's not useful to them, just like much of earth is not that useful to us. Oh the irony.

I doubt the sun would care about that scale. But again - SciFi terrain....
Nuclear power is clean exactly at one point - when the plant is in operation and is working without major failures. The mining and processing of the fuel, the handling, processing and storage of the waste and the deconstruction of the contaminated plants themselves are all not exactly clean.

That looks nasty. Oh well, I just hope power efficiencies will continue their current trajectory on computer hardware, because I'd hate to cut down my usage because lack of electricity.

Originally Posted by Moco Loco

Due to the scale of the sun, I hardly think it would cause issues of any kind I'd be more concerned about if something would go wrong on its way away from Earth

When you watch enough bad sci-fi movies like the Sunshine, you begin to wonder about all kinds of possibilities.

Anyhow, at least the waste would no longer be our concern once out there, but then again littering is not very nice. Space is pretty huge though, so I doubt anyone would notice...

[Clarke]

Originally Posted by Aquaplant

Nuclear power is clean, but the waste is not, so it's rather difficult equation. We need a cheap space elevator to dump all the nuclear waste into the sun. Though I wonder would that cause some stability issues over long term? Dumping fission waste into fusion doesn't really sound like the best idea... Then again on paper that makes perfect sense, if only the fission would be much smaller in scale that it is with uranium.

If we're going to be dumping things into spa(aaaaaaaaaa)ce, we actually want to throw them out of the solar system, rather than into the sun; it's cheaper. (Did I mention that orbital mechanics is rather strange? )

However, we shouldn't throw it anywhere just yet, because nucelar fuel can be recycled several times over. Check out that last sentence: "Finally, the breeder reactor can employ not only the recycled plutonium [...] potentially multiplying the energy extracted from natural uranium by more than 60 times."

The technology is mostly there, but it's being impeded by the irrational fear of "nuclear" anything, as well as the (IMO) scaremongering of nuclear terrorism. Nuclear fission on its own is capable of mostly solving energy issues, and the resulting mess is orders of magnitude less environmentally harmful than coal/oil plants: the radiation of the waste produced by breeder reactors falls to "unconcerning" levels within a few hundred years. (This isn't quite the same thing as "safe," but it's low enough that you'll have no major problems unless you stay in the area 24/7 for days at a time.)

And they wonder why experimental scientists hate theoretical scientists...

"Assuming a spherical cow..."

Originally Posted by auroraglacialis

...Applied to a small scale, this would translate into about 3m² per Person. That is a dish of about 2m in diameter!

Everything you've said is tecnically correct, but it's unviable. For instance, even the densest cities are still sparse enough for everyone to fit their 2m solar dishes into, but not all cities are sunny enough. Edinburgh, for instance, is so cloudy that solar would almost be useless. Where would those 400,000 people get their power? (You can't grab it from somewhere else, because the resistive loss would be prohibitave.)

A problem of course is intermittency, so that machine would probably produce 3000W one day and zero the next night. This means heat or electricity has to be stored and used when it is available. This is also why the general idea is to have an "energy mix" with for example biogas jumping in to fill the gaps.

Attempting to store heat directly essentially has you run headlong into fighting the laws of thermodynamics. Additionally, all current power storage technologies apart from hydropotential are vastly inefficient.

There is no need to put these things into orbit or on Mercury - there is plenty of sun here. Maybe not enough for everyone to live wastefully or for everyone to have a personal electric helicopter or something, but d'oh - I guess we can for now live without that.

Just to point this out: Mercury's solar constant is 9kW/m^2, 6 times that of an ideal Earth. (In practice a lot more, because Mercury does not have any sort of clouds, and possibly even has so called "peaks of eternal light.") Hence, once we have the technology, there is a lot more power on Mercury than there is on Earth, even if we can live off Earth for the time being.

Re the environmental destruction - I agree that this is the case. As it is for ALL energy production systems.

Apart from fusion, which is on the horizon. (Seriously, commercial prototyping is due before 2020, IIRC. We'll have it soon! ) Once you've got a fusion station up and running, it'll crank away quite happily for decades with no further rare materials of any sort. If it's automated (a concept I don't think I've seen before) that lifespan could easily be 40-50 years, if not longer.

There are basically no large scale options that go around this because electricity and high technology itself needs these minerals and processing. No matter if that is any kind of electricity generators (needs magnets), electronics (REEs, copper, gold) or appliances (copper, plastics, special metals). There are some that pollute less, one of them is hydrothermal where it exists, another is solar thermal.

All the remotely green technologies involved still involve rare-Earth mining, and aren't that reliable.

Ah, lets hope no stupid romantic native people are sitting on that then

Resistance is futile.
...I'm sorry, that was terrible. More seriously, if there's a particular problem with gathering it, whether ethical, political, or practical, then it'll get synthesized pretty quickly. (We might run into additional issues if that process is then patented, but patents only last 20 years.)

And is NIMBY such a strange idea? Seriously I think we need more NIMBY everywhere, because people should not have to put up with having some stuff happening in their vicinity that supposedly is to the better of the nation or mankind. Who are we to say that some people living in some place are supposed to take the risk or pollution while others take the benefit. I am sure you (Clarke and HNM) would happily like to live in the shadow of a nuclear power plant and enjoy the view, but many people do not and to tell them they are wrong and just put the stuff there - thats not working.

If it were possible to build it so, I'd spread the risk equally. (Another advantage of solar panelling Mercry: nobody lives there. ) This is fairly basic politicism: some people must their freedom* impinged in order to serve the greater good of the society. To argue aginst that principle basically involves arguing against the entire concept of an overruling government, which leads into anarchy, which leads into non-anarchy due to how humans work.

*Even this is arguable; you are free to move away if you wish.

[Aquaplant]

Originally Posted by Clarke

If we're going to be dumping things into spa(aaaaaaaaaa)ce, we actually want to throw them out of the solar system, rather than into the sun; it's cheaper. (Did I mention that orbital mechanics is rather strange? )

It might be safer not to litter too much in space on the account of there being a alien race that is neurotic about galactic purity and stuff, and would use their giant energy cannon of doom to remove the source of disturbance.

However, we shouldn't throw it anywhere just yet, because nucelar fuel can be recycled several times over. Check out that last sentence: "Finally, the breeder reactor can employ not only the recycled plutonium [...] potentially multiplying the energy extracted from natural uranium by more than 60 times."

The technology is mostly there, but it's being impeded by the irrational fear of "nuclear" anything, as well as the (IMO) scaremongering of nuclear terrorism. Nuclear fission on its own is capable of mostly solving energy issues, and the resulting mess is orders of magnitude less environmentally harmful than coal/oil plants: the radiation of the waste produced by breeder reactors falls to "unconcerning" levels within a few hundred years. (This isn't quite the same thing as "safe," but it's low enough that you'll have no major problems unless you stay in the area 24/7 for days at a time.)

Can I get the proper link? The spherical cow isn't going to help me understand how recycling nuclear reactor works, and I'm too lazy to google it.

[auroraglacialis]

Originally Posted by Aquaplant

At least they are sitting on something more useful than we are, but then again it's not useful to them, just like much of earth is not that useful to us. Oh the irony.

erm, sorry, but what we are sitting on is pretty useful, given that it is the reason we are alive in the first place and stay so for some 8 decades after we are born? I'd call that pretty darn useful!

That looks nasty. Oh well,[...] I'd hate to cut down my usage because lack of electricity.

Ok, that is a mean cut of your quote but I think it is not giving a completely wrong picture...

Anyhow, at least the waste would no longer be our concern once out there, but then again littering is not very nice. Space is pretty huge though, so I doubt anyone would notice...

Originally Posted by Clarke

If we're going to be dumping things into spa(aaaaaaaaaa)ce, we actually want to throw them out of the solar system

I think a major problem is getting it there safely (e.g. without transports falling back to Earth). The other is more theoretical, but I'd like to point out that the first people using oil were pretty much convinced that there is no way doing that could change the atmosphere of the whole planet, after all it is unimaginably huge and no one would notice... Another silly though was, what would we think if an object from outer space would come into the solar system after some thousand years of travel and we would find it, man a multi billion dollar expedition - to find out it is a huge barrel of still radioactive waste heading for the inner planets

"Finally, the breeder reactor can employ not only the recycled plutonium [...] potentially multiplying the energy extracted from natural uranium by more than 60 times."

I dont get what the spherical cow has to do with that one, but I guess you talk about nuclear fuel reprocessing. This basically means to remove unusable substances from spent fuel, make new fuel from the rest and also include plutonium int he fuel mix. I think this is not easy and not without risk, especially handling plutonium. A 60-fold increase would mean that the world at current rate of electricity consumption could run 600 years when producing all its electricity by nuclear power (that is an upper estimate, starting at 200 years of Uranium reserves at present day production, a 60-fold increase by reprocessing, a 20-fold increase of the percentage of nuclear power in electricity generation from now 5% to 100%). World energy demand is likely to multiply within that timeframe though, effectively reducing the runtime of this to maybe 1-2 centuries. This is using total reserves - peak production would probably be reached a lot sooner - just as peak oil will come long before oil really is all used up and the peak is what makes a resource undesireable afterwards. 1-2 centuries are impressive but not something to rely on for the future. It can at best be a "bridge technology".

The technology is mostly there, but it's being impeded by the irrational fear of "nuclear" anything, as well as the (IMO) scaremongering of nuclear terrorism.

I dont think that this is necessarily scaremongering. It may be so when one talks about some bunch of extremestis building a bomb in their garage, but on a larger picture - nuclear war is a major threat to the world. Just look at the whole deal with Iran and Israel right now. Also China and India are about to fight over water resources in the Himalaya - both having "the bomb". Everyone is scared of using it, but that does not mean no one will. Also as I mentioned before - in a conventional war, a country that has nuclear facilities has severe liabilities with these installations. They would have to be protected at all cost, even if that means whole cities being destroyed elsewhere. And if they do not manage to provide that protection - well I dont want to see that one...
Just imagine the UN would now start to invade Iran because they are building the bomb - and someone hits the wrong part of the production facility because intelligence was wrong - large parts of that country would be irradiated.

Everything you've said is tecnically correct, but it's unviable. For instance, even the densest cities are still sparse enough for everyone to fit their 2m solar dishes into, but not all cities are sunny enough. Edinburgh, for instance, is so cloudy that solar would almost be useless.

Well maybe that map is wrong, but looking at it, no part of the map has a value lower than 700. So you'd need a 3m solar dish. I think there is still plenty of room for those. But for the UK I think at least a partial use of wind power makes more sense anyways.

Attempting to store heat directly essentially has you run headlong into fighting the laws of thermodynamics. Additionally, all current power storage technologies apart from hydropotential are vastly inefficient.

Thermal energy storage - Wikipedia, the free encyclopedia

Molten salt can be employed as a thermal energy storage method to retain thermal energy collected by a solar tower or solar trough so that it can be used to generate electricity in bad weather or at night. It was demonstrated in the Solar Two project from 1995-1999. The system is predicted to have an annual efficiency of 99%, a reference to the energy lost by storing heat before turning it into electricity, versus converting heat directly into electricity. The molten salt is [...] non-flammable and nontoxic
[...]
hot storage tank. This is so well insulated that the thermal energy can be usefully stored for up to a week

Of course this is unviable for actually placing 2m dishes with generators on every house, but lets say put one such plants tower in the center a town and some mirrors on every roof and it may work. Or if people like that better one could also just build a field of these, but I personally dislike such large scale land-changing measures. With wind other ways may have to be found as they are not thermal machines.

Just to point this out: Mercury's solar constant is 9kW/m^2, 6 times that of an ideal Earth

Oh no doubt. And if you go inside that Orbit it is even better. Or you could create a huge fresnel lens and bundle the light of the sun onto the moon and ... ah whatever... SciFi

Apart from fusion, which is on the horizon. (Seriously, commercial prototyping is due before 2020, IIRC. We'll have it soon! )

Yay finally I may say this: "[Citation needed]"
But seriously - fusion power is "just around the corner" for the past about 25 years I took interest in that topic. It always is just 20 years away from application. This is the "20 year constant" as me and some physicist friends call it. What happens is that always new challenges pop up. If you also have a subscription to Scientific American, there was an article in there on that just last year: Fusion's False Dawn: Scientific American

All the remotely green technologies involved still involve rare-Earth mining, and aren't that reliable.

I dont say that it is a benign solution but take those solar concentration plants. They need glass and aluminum for the mirrors, metals and ceramics for the collector, some nitrate salts (fertilizers) for heat transfer and storage, steel and rubber for the pipes and turbines, copper and magnets for the generators and probably a lot of plastics and concrete. All not great but hardly any more toxic than any other powerplant that is feasible right now.
Personally I'd like to see a lot less of these machines, but as everyone keeps pointing out, this is only possible with a strong reduction in energy demand.

some people must their freedom* impinged in order to serve the greater good of the society. To argue aginst that principle basically involves arguing against the entire concept of an overruling government

Oh really?

*Even this is arguable; you are free to move away if you wish.

Yeah I know. "They can move"....

... unless eventually there are no places left to move to (or they are sold at a premium to the rich).

[Clarke]

Originally Posted by Aquaplant

It might be safer not to litter too much in space on the account of there being a alien race that is neurotic about galactic purity and stuff, and would use their giant energy cannon of doom to remove the source of disturbance.

Space is big. Very big. You might think it's a long way down the street to the chemist's... Unless it happens to be entering your solar system, you probably won't even be able to see it, that's how big space is and/or how small any man-made object is.

Can I get the proper link? The spherical cow isn't going to help me understand how recycling nuclear reactor works, and I'm too lazy to google it.

Oops, here it is: Nuclear reprocessing - Wikipedia, the free encyclopedia