h a l f b a k e r yPoint of hors d'oevre
add, search, annotate, link, view, overview, recent, by name, random
news, help, about, links, report a problem
browse anonymously,
or get an account
and write.
register,
|
|
|
Instead of installing expensive power lines, crushing
digging and mining the ore, and then using wasteful non-
renewable energy for melting the ore and creating the
copper (or other precious metals) why not just use a
"solar
furnace" directing and concentrating sunlight from these
largely
desert areas, directly into the mine or cave,
melting the
ore directly on its location, and then handling it from
there.
composition of Solar Wind
http://sohowww.nasc...ons/compos9_12.html
per an annotation that misinterpreted the title of this Idea. Copper isn't high on the list of common elements in the Solar Wind, but be assured it is there. [Vernon, Nov 09 2012]
Copper extraction techniques
http://en.wikipedia...traction_techniques
[spidermother, Nov 10 2012]
[link]
|
| |
// non- renewable energy // |
|
| |
Solar energy is not actually "renewable". |
|
| |
Electrolytic refining of copper is actually the most energy-efficient method available. |
|
| |
If radiation from the sun and the resulting products are not "renewable", then we really are up shits creek without a paddle. "Recycling" is the most energy efficient mechanism for satisfying the demand for copper. |
|
| |
Solar radiation isn't renewable. Once a photon from the sun
hits you, that photon will never hit you again, and when
the sun is all out of photons, that's it. No renewal. |
|
| |
Oh, and this idea is Bad Science in more ways than I care
to count, though I'm sure others will. |
|
| |
^^^ Schlee's right. Except that I thought electrolysis was to purify the (already refined) copper. [Edit] (terminology fail) It's typically *smelted* with coke, *reduced* with natural gas, then *refined* electrolytically. |
|
| |
Anyway, what they ^ all said. "Just add solar" [-]. |
|
| |
//If radiation from the sun and the resulting products are not "renewable", then we really are up shits creek without a paddle.// Now you're getting the hang of it! |
|
| |
//Solar energy is not actually "renewable".// |
|
| |
It is definitionally “renewable energy”. If you're
talking about some sense of the word “renewable”
that cannot be used to describe sunlight, you're no
longer referring to the word that is used as part of
the phrase “renewable energy”, but rather some
homonym of that word. |
|
| |
[Marked-for-Deletion] WKTE |
|
| |
Conceptually, at least. The practicalities are far
from solved. |
|
| |
//It is definitionally “renewable energy”.// |
|
| |
That's precisely the problem. People just say "solar's renewable", then drift of into a cloud-cuckoo land where you are no longer required to practice valid accounting - the energy and resources consumed by the solar harvesting project, and the Nth order resources consumed in providing those resources, is simply ignored. Solar may be (and probably sometimes is) less bad than many of the alternatives, but that doesn't grant a license to hide one's head in the sand. |
|
| |
While solar fusion is not, technically, renewable,
it can be considered such for two reasons. First,
that if we haven't come up with alternatives in
the nine billion years before it goes out, it's
probably because we aren't around any more (as a
species) to care about it. Second, we don't have
any way to slow it down or stop it, so it's more
wasteful not to use it than to use it. |
|
| |
Beyond that is the question of whether harvesting
solar energy is renewable. In it's simplest form,
the answer is yes. Harvesting food and burning
biomass can be 100% renewable. |
|
| |
Beyond that, the more sophisticated your
harvesting gets, the more difficult that question
is to answer. If, however, sufficient power is
available, then it becomes possible to completely
recycle all components of any solar harvesting
system at the end of life. I believe, although I
cannot find hard numbers, that the EROI on the
latest generation of PV panels is sufficiently high
that they do, in fact have a net positive return
even if complete recycling is taken into account.
(This doesn't mean such recycling will be done, it's
still cheaper to mine new.) If it can be done,
then yes, the panels are completely renewable. |
|
| |
We assert that there is a predictable upper
limit to your primary's energy output,
calculable directly from its mass and rate of
hydrogen conversion, and therefore it is not
"renewable"; it is a fixed and time-limited
resource. |
|
| |
[MechE] With those provisos, I agree with you. |
|
| |
Yes, but that's not the meaning of the term “renewable energy”. You're shifting the
goalposts here by focusing on an alternative definition of “renewable” that is not the
one used in the context of “renewable energy”. “Renewable energy” refers specifically
to energy derived directly from resources that are naturally replenished, including
sunlight. You seem to be misapplying the term “renewable” to mean “unlimited”. |
|
| |
It's like claiming that “antisemitism” doesn't mean hatred of Jews because you're
applying an alternative definition of the word “semitic”. That's all well and good, but
focusing on a homonym for part of the phrase in order to attack the usage of the entire
phrase is a straw man. |
|
| |
Don't you try and out-pedant me, [8th]. I am the pit bull of pointless pedantry (say
/that/ ten times fast). |
|
| |
Example: production of fuel ethanol from purpose-grown maize. The total fossil fuel energy consumed (using deep energy accounting) almost certainly exceeds the ethanol energy delivered to the end user. But if there is any net fossil fuel consumption, the overall process is less than completely renewable. My view is that the goalposts are misplaced in the mainstream definition, which tends to ignore such bedevilled details and say "it's bio-fuel / solar / whatever, therefore it's renewable". |
|
| |
Solar energy is renewable as long as you don't actually mean "renewable". |
|
| |
I will fully agree that corn ethanol is one of the
stupidest things anyone ever came up with, but
I'm not certain it's EROI is below one. I'm not
certain it's above, either. |
|
| |
Sugarcane ethanol does better, and is almost
definitely well above one, although how far is
open for discussion. |
|
| |
I'm still hoping that one of the cellulosic ethanol
plans will work out, but we shall see. |
|
| |
Flat plate solar thermal definitely is, concentrated
solar thermal probably is. PV is, I think, and is
getting better as greener manufacturing
approaches are found. |
|
| |
Wind EROI is far above one, as is hydro if sufficient
effort is made to avoid damaging the local fish
stocks. (Treating those as food that needs to be
replaced). |
|
| |
Nuclear is wonderful in that respect, at least once
we switch over to low waster reactors that reduce
the need for thousands or millions of years of
care. It's not actually renewable, however. |
|
| |
We're kind of missing the point here. “Renewable energy”
is a term of art that is defined to encompass solar energy
(check Wikipedia—it's in the very first sentence). But
beyond that, regarding the non-renewability of the Sun: |
|
| |
//We assert that there is a predictable upper limit to your
primary's energy output, calculable directly from its mass
and rate of hydrogen conversion, and therefore it is not
"renewable"; it is a fixed and time-limited resource.// |
|
| |
So, you can't think of any way to increase its mass? I
suggest a fact-finding mission to the surface of the Sun—
and if you go, the Earth thanks you for your contribution to
the longevity of its main energy source. |
|
| |
Simply because we do not have any influence over the
sustainability of the sun doesn't mean that solar fission isn't the
most sustainable and most renewable form of energy production
available in this universe. No other technique for producing
energy from raw materials even comes close to the output of a
star for the ability to renew the useful output over time. Is most
of the energy wasted? Yes. Does it mater? No. Is it matter? Yes. |
|
| |
[WcW], the Sun uses fusion to produce energy, not fission. |
|
| |
Anyway, I thought this Idea would be about extracting copper atoms from the Solar Wind.... |
|
| |
//Solar energy is not actually "renewable".// |
|
| |
Sources of negentropy the harvesting of which does not greatly impact their abundance or availability may be loosely regarded as "renewable" sources (although "renewing" would be more technically correct). If they can be harvested in such a way that the abundance or availability of other (non-"renewable") resources is not reduced, then the result may be regarded as sustainable negentropy harvesting. |
|
| |
In a non-technical setting, the word "energy" may be used as a short-hand for high grade energy (that is, concentrated negentropy, used or usable by humans). |
|
| |
^ You just have to shake the flask really really hard. |
|
| |
I played in a D&D game where a character had an item like
that. It worked on magic. |
|
| |
As far as I understand, and please just correct me
without any snide remarks if I'm wrong, that the
smelting stage is done with a source of carbon such as
coke fuel and [bold] heat, a lot of heat, at very high
temperatures. [/bold] |
|
| |
So extraction of iron, copper, silver and other metals
from the ore needs a lot of energy, which is usually
NOT AVAILABLE at the location, and also is very
expensive. |
|
| |
Concentrating and sending light deep into a cave
seems to me to be anything but "bad science". |
|
| |
So, Alterother or any other boner, please spell out
the bad science here. |
|
| |
This idea was written after a visit to the desert mines
of ancient times in Timna, where slaves dug the ore
in deep mines, then sent it up to a furnace, where
the copper was extracted by heat and charcoal. |
|
| |
and c'mon. So call it "clean energy". I didn't think you
were all pedantic. |
|
| |
I went with WKTE because solar furnaces are an old
technology. Several attempts have been made to
get them to metal smelting temperatures, and one
or two exist, but the practicalities have kept them
from being economical so far. |
|
| |
Iron needs 1250C. Solar furnaces reach 3500C and
more. See wikipedia "solar furnace" |
|
| |
Yeah, yeah, smelters are hot, solar furnaces are hot. We all get that. But there's nothing to be gained from heating the ore in the mine. It needs to be extracted ... prepared ... diced! And the heat in a copper smelter comes from the reaction itself - not from some external source. And the difficulty is not that no-one has thought of it - they have - but that it is difficult. |
|
| |
Copper foundries typically heat the metal to between 1900
and 2250
degrees before the pour, and even if the founding process
were simply a matter of melting the metal (which it is not;
various solid and gaseous additives must be introduced at
different stages), the sustained BTU requirements of an
industrial
copper foundry range into the low millions. The biggest
solar furnace I can find on the web cranks out around
700,000 over a six-hour run. |
|
| |
Those technical quibbles, however, only apply once you've
got the metal to the foundry. Getting it out of the ground,
extracted from the ore, and refined into usable form is a
much bigger and more complicated task, and only the very
last stage (smelting) involves any
significant amount of heat, which, as [spidey] pointed out,
is not solely generated by an external source. Simply
introducing intense heat directly
to a chalcocyte
deposit accomplishes nothing other than warming up a bit
of orange-ish rock. |
|
| |
That brings me to my next issue; the site you visited bears
little resemblance to the copper mines of today.
Nowadays, copper-bearing ores are nearly always mined in
open-pit mines or via hillside/hilltop removal, so instead
of directing concentrated sunlight into a shaft or tunnel,
you'd have to cast it over a very wide area. Assuming your
concept were possible, this would require a light collection
and concentration appuratus many times larger than the
mined area (which themselve can be 50 square miles,
sometimes more), and building such an installation would
consume so much energy that you could practically never
balance it out with the amount of non-renewable energy
you'd be 'saving.' |
|
| |
Finally, the idea that you could heat even pure metal to
melting temp while it's still in the ground strains credulity.
The Earth is the biggest heat sink on Earth. |
|
| |
The bone isn't mine. I'd much rather mock than bone. |
|
| |
//I'd much rather mock than bone.// But for those of us unable to mock... |
|
| |
But for Timna and similar places (dark red rock btw, not
light orange) this would be fit. Because of the
concentration of energy heat loss would be irrelevant.
It would act like plasma gasification does with metals
(they "leak down" out of the other material). |
|
| |
I'm not saying this is the whole process. Its just a cheap
way that may do a large part of the process. |
|
| |