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#1 2016-12-02 10:54:07

Void
Member
Registered: 2011-12-29
Posts: 6,976

Heliostats on Mars, and other worlds.

https://en.wikipedia.org/wiki/Heliostat
http://www.heliostat.us/
Quote:

Hands down the cheapest way to gather the suns energy

Or at least someone thinks so.

I have found that it should be prudent to introduce Heliostats to their own section, as it seems that here the only application accepted are typically for warming up cold Plamemo's.

To some extent conversation has bumped on making basalt bricks with a solar concentrator.

And the body of works has mentioned using some type of mirror to melt the polar ice caps of Mars.  That will be hard to implement, but it remains a possibility, in my opinion.

This level of application is much more attainable within our lifetimes, and is in fact being implemented in large ways here on Earth already.

Types of heliostats that I am aware of existing are.
-Augmented lighting.
-Solar ovens.
-Individually functional heliostats where each mirror has it's own focal target, and a fluid is typically heated in the focus.
-Collective power tower heliostats.

I think that all of these are to some degree in current representation on Earth today.

And now, here I go, another proposed item, specially built for icy worlds, which in our solar system typically have low atmospheric pressure.

Mars, Ceres, Callisto, Ganymede, Europa? (Nasty place).

The deviation being Titan, Titan has a good thick atmosphere, but unless the smog removed (And you might not want to), then Heliostats are not a good choice for Titan, unless they are orbital.

But our primary desire is Mars.

Heating and lighting H20 Canal waters.

In reality on Mars today, a greenhouse covering is required for practicality, and even in the future almost always will be.

An exception to that generalized rule could be the melting of polar ice caps with ground heliostats or orbital ones.

Orbital has been covered previously by others, so I suggest I will contemplate ground based heliostats.

Melting rivers of water from the North polar ice cap, seem less productive to current purpose due to elevation, than melting the South ice cap, so I will focus on the South ice cap.

In my view, if a significant ice body has been developed in a location such as Utopia Planetia, and then Hellas Planetia proves to be what it might hope it is, humans might want to melt rivers from the South polar ice cap, the run into the Hellas depression.

I am presuming that by the time this is implemented greenhouse gasses will have increased average atmospheric pressure on Mars to perhaps ~11 mb or more.  In the bottom of Hellas, then there should be a pressure of >22 mb, maybe approaching 30 mb.

The rivers desired could flow right now from the south ice cap into Hellas perhaps, but of course the energy needed would be very large, and the evaporative losses would be very large as well.

So, I am expecting a increase in atmospheric pressure, and if desired the implementation of heliostats pointed at elevated portions of the south ice cap to liquefy those portions, producing a river.  The rivers produced for the most part can be expected to be ice covered, which will reduce evaporation.  Means to heat the flowing water more, should it start to freeze may be required.  However the process of flowing will heat the water, so it is not as formidable a task as might be imagined.  The turbulence of the water flowing downhill will tend to heat it.

If I got close, then great.  If it needs more work, so be it.

Don't do your standard procedure and try to snuff this idea.

Last edited by Void (2016-12-02 11:22:47)


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#2 2016-12-02 12:46:17

elderflower
Member
Registered: 2016-06-19
Posts: 1,262

Re: Heliostats on Mars, and other worlds.

For local melting, eg of a cliff exposure of ice, this might work. For melting ice caps and making rivers, I'm not so sure. This method doesn't increase the available heat, it moves it to one location at the expense of the area where it would otherwise have arrived. If you want to melt ice caps an orbiting mirror arrangement has the advantage of increasing total heat gain. You will also have to reduce heat losses to space by, perhaps, adding lots of sulphur hexafluoride and fluorocarbons to the atmosphere.

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#3 2016-12-02 15:49:18

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Heliostats on Mars, and other worlds.

I think you have to factor in time.

If you capture solar energy and absorb it into a phase change of water from ice to liquid, you are delaying the time it takes for the sunlight to hit a surface on Mars, and when the energy of that sunlight passes out into space.  The two primary methods for that energy to go out into space are reflection and radiation, typically infrared.

As for shading one spot with a heliostat, and adding sunlight to another spot to make it exceed the melting point of water ice, that really does no harm, as ice has a single point of melting, 0 degC / 32 degF.

A natural example of this would be a river which feeds liquid water into a Antarctic Dry Valley lake.  I believe that the Onyx river only runs a couple of weeks a year from meltwater, and fills a dry valley lake.

https://en.wikipedia.org/wiki/Onyx_River

Lake_Vanda_map.jpg

Lake Vanda:
https://en.wikipedia.org/wiki/Lake_Vanda
Lake_Vanda_with_Onyx_River.jpg
Quote:

Ice-covered Lake Vanda with Onyx River in the right foreground

Quote:

Lake Vanda is a lake in Wright Valley, Victoria Land, Ross Dependency, Antarctica. The lake is 5 km long and has a maximum depth of 69 m.[2] On its shore, New Zealand maintained Vanda Station from 1968 to 1995. Lake Vanda is a hypersaline lake with a salinity more than ten times that of seawater,[3] more than the salinity of the Dead Sea, and perhaps even more than of Lake Assal (Djibouti), which is the world's most saline lake outside of Antarctica. Lake Vanda is also meromictic, which means that the deeper waters of the lake don't mix with the shallower waters.[4] There are three distinct layers of water ranging in temperature from 23 °C (73 °F) on the bottom to the middle layer of 7 °C (45 °F) and the upper layer ranges from 4–6 °C (39–43 °F).[5] It is only one of the many saline lakes in the ice-free valleys of the Transantarctic Mountains. The longest river of Antarctica, Onyx River, flows West, inland, into Lake Vanda. There is a meteorological station at the mouth of the river.


Ice-covered Lake Vanda with Onyx River in the right foreground
The lake is covered by a transparent ice sheet 3.5–4 metres (11–13 ft) year-round, though melting in late December forms a moat out to approximately 50 metres (160 ft) from the shore. The surface of the ice is not covered with snow and is "deeply rutted with cracks and melt lines".[5] During the colder months the moat refreezes.
While no species of fish live in Lake Vanda or the Onyx River, microscopic life such as cyanobacteria algal blooms have been recorded. Due to the concerns over impact to the natural environment that may occur during research, scientific diving operations are limited to work in the upper layer (above 30 metres (98 ft)) and remotely operated underwater vehicle use is not allowed.[

Another link:
http://aem.asm.org/content/81/6/1988.full
Quote:

Besides supplying heat, this deep influx of solar energy supports a phytoplankton bloom at a 55- to 60-m depth, where the relatively warm temperatures and inorganic nutrients diffusing upward from the brine stimulate photosynthesis (10).

Last edited by Void (2016-12-02 16:12:21)


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#4 2016-12-02 16:13:49

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Heliostats on Mars, and other worlds.

So, you see what can be gained!

Hellas in it's entirety could be a giant solar collector, protected from U.V. by ice, and could support photo life.  In fact with some manipulation of nutrients the photo life could be much higher in the water column.

But, why preclude solar orbital mirrors?  Those too, when they are most useful.

But a smaller project could be done.  There are surely smaller valleys with salt in their soils that could be "Terraformed" by adding water.

Would you like to swim on the bottom of such a body of water at 23 °C (73 °F)?
It could be possible.

Evaporation from the ice is going to be a problem.  It will be necessary to thicken the atmosphere of Mars.  This I presume would indeed involve greenhouse gasses.

I understand that by doubling the pressure on Mars, snow will be possible, and temporary melt water streams.  What this may say about evaporation is questionable.  Surely it should help.

Last edited by Void (2016-12-02 16:25:20)


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#5 2016-12-02 16:28:08

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Heliostats on Mars, and other worlds.

A way around the problem would be to melt the polar ice caps themselves, particularly the North polar ice cap.

However this would induce a fresh water lake, which would be cold all the way to the bottom.  But evaporation would not be a problem as where else does the water vapor on Mars have to condense.

So, Heliostat methods, orbital, and surface could be used to create melted bodies of water at the poles.

I prefer a sea in Hellas however, with warm water in it's lower layers.


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#6 2016-12-02 16:29:53

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Heliostats on Mars, and other worlds.

The four evil subjects that most members won't talk to me about at New Mars!

1) Mushrooms.
2) Dry Valley Lakes.
3) Heliostats (You broke the code elderflower!)
4) Polar Seas.

Zzzzzzzzzzzzzzzzzzzzzzzz.......................................... smile

Last edited by Void (2016-12-02 16:30:41)


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#7 2016-12-03 05:45:27

elderflower
Member
Registered: 2016-06-19
Posts: 1,262

Re: Heliostats on Mars, and other worlds.

The dry valley lakes are a better model for Europa, I think. They might be of use in understanding Mars lakes but we have to make them first.

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#8 2016-12-03 10:18:07

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Heliostats on Mars, and other worlds.

Yes, the whole of Europa, we think bears some resemblance to a Dry Valley Lake.

However the primary source of warming is from tidal stretching of rocks.  I also bet that heating is happening from Serpentization.

And the likelihood of any meaningful amount of light projecting into the presumed waters of Europa is very low to zero.

But there is a similarity of process, and therefore a resemblance.

There are almost certainly freeze dried dry valley lakes on Mars.  All you would need to do is to add water and inhibit evaporation.
So, we are in a situation of excellent possibilities in my opinion.

The situation is not unlike humans ability to make fire.  You leverage a small effect and a small burden into a big reward, if you get the technology right.

Last edited by Void (2016-12-03 10:26:57)


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#9 2016-12-03 19:05:36

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: Heliostats on Mars, and other worlds.

Solar energy at Earth 1300 watts or over 150,000 lumens at orbit distance averaging a mere 1100 at the surface per meter squared but at Mars is by far less. Solar Theral efficency is aroud the 60% - 70% typical for designs while the most advance solar cells are around 40%.

As you can see by the images in this page https://en.wikipedia.org/wiki/Heliostat with the https://en.wikipedia.org/wiki/Solar_power_tower being another type with an array of flat, movable mirrors (called heliostats) to focus the sun's rays upon a collector. https://en.wikipedia.org/wiki/Concentrated_solar_power Which can mirrors or lenses to concentrate a large area of sunlight.

The concentrated light is converted to heat, which drives a heat engine (usually a steam turbine) connected to an electrical power generator.

A parabolic trough consists of a linear parabolic reflector that concentrates light onto a receiver positioned along the reflector's focal line. The receiver is a tube positioned directly above the middle of the parabolic mirror and filled with a working fluid. The reflector follows the sun during the daylight hours by tracking along a single axis. A working fluid (e.g. molten salt) is heated to 150–350 °C (300–660 °F) as it flows through the receiver and is then used as a heat source for a power generation system.

With a variation a design encapsulates the solar thermal system within a greenhouse-like glasshouse. The glasshouse creates a protected environment to withstand the elements that can negatively impact reliability and efficiency of the solar thermal system.

There are other working fluids that can be used to collect the heat energy in these designs of which oil, Freon, Amonia plus many others come to mind.

But starting to build them will need equipment on mars to create the reflective surfaces, collection tubes and many more parts from insitu materials as we can only afford a smal mass allotment for this type of project at the start of exploration to a base colony effort.

Bucket list item number 3 started out, now for sure....

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#10 2016-12-03 19:49:43

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: Heliostats on Mars, and other worlds.

Void wrote:

The four evil subjects that most members won't talk to me about at New Mars!

1) Mushrooms.
2) Dry Valley Lakes.
3) Heliostats (You broke the code elderflower!)
4) Polar Seas.

Zzzzzzzzzzzzzzzzzzzzzzzz.......................................... smile

here is the Mushroom topic http://newmars.com/forums/viewtopic.php?id=6910

If I recall there are signs from orbit that there is a seasonal brine that stains the slopes of craters in serveral spots so we have the making of the Dry valley lakes http://newmars.com/forums/viewtopic.php?id=7522

Polar seas would require an very large dome to make possible and lots of heat generation to keep it in liquid form...

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#11 2016-12-03 20:35:09

Antius
Member
From: Cumbria, UK
Registered: 2007-05-22
Posts: 1,003

Re: Heliostats on Mars, and other worlds.

SpaceNut wrote:
Void wrote:

The four evil subjects that most members won't talk to me about at New Mars!

1) Mushrooms.
2) Dry Valley Lakes.
3) Heliostats (You broke the code elderflower!)
4) Polar Seas.

Zzzzzzzzzzzzzzzzzzzzzzzz.......................................... smile

here is the Mushroom topic http://newmars.com/forums/viewtopic.php?id=6910

If I recall there are signs from orbit that there is a seasonal brine that stains the slopes of craters in serveral spots so we have the making of the Dry valley lakes http://newmars.com/forums/viewtopic.php?id=7522

Polar seas would require an very large dome to make possible and lots of heat generation to keep it in liquid form...

I don't know much about fungi, that is why I don't talk about them.  I provide feedback when I think I have something useful to offer.  My limited understanding of fungi tells me that they are not primary producers.  If you provide plant matter or some other organic material they will derive energy by breaking it down.  They are an important part of Earth ecosystems as they help close the loop.  In what context do you wish to see them discussed?

As for polar seas, they could be stable at Martian atmospheric pressure if covered in ice.  An internal heat source would be needed to keep the water under the ice liquid.  On the scale of an entire sea, the power required would be formidable.  Smaller crater lakes could be kept liquid with more modest heat addition.

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#12 2016-12-03 21:05:20

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Heliostats on Mars, and other worlds.

Thanks for the replies to my last post guys.

Mushrooms/Fungi:
Should we foster livestock that eats plant matter, we can nominate;
-Cattle
-Chickens (Not strict vegetarians).
-Black Sodier Fly Larvae
-Fish
-Mushrooms

Of these proposed livestock, Cattle and Chickens are warm blooded, and so we can expect them to consume calories and Oxygen to maintain their body temperature.  We should perhaps want to look at the other candidates instead.
So,
-Black Sodier Fly Larvae
https://en.wikipedia.org/wiki/Hermetia_illucens
-Fish
-Mushrooms

Of the above, Black Sodier Flies and fish are animals.  Therefore they are animated, have muscles.  Therefore they will consume calories and Oxygen moving around.  So in my opinion we should perhaps want to look at the remaining candidate.

Some Fungi have sex organs that we call Mushrooms.  That is sort of disgusting in a way that we remove them and eat them, but if the organism is assisted in its propagation, I do not consider it to be and unthinkable immoral act.  Many plant products we eat are after all the seeds of life for plants.  It isn't that different.

Eating Mushrooms, I think is of a greater morality than killing animals to eat.  I am not a wacko however, I do eat meat.  I understand that the animals eaten would most likely not have had a life if it was not for that purpose.  We can only hope that morality can be applied to the raising livestock, and that eventually humans will not have to kill such animated life to survive.

Fungi which produce Mushrooms, can digest many organic biologically produced materials, and weird things like Oil and Coal/Carbon.
And the resulting leftovers are beneficiated as a soil additive for photo-plant growing.

Foods you could feed your fungi, include your body waste, (But be careful about parasites).  Carbon taken from the atmospheric CO2, (Which would leave you with O2 to breath.  If there is Methane in the ground as Clathrates (https://en.wikipedia.org/wiki/Methane_clathrate) then you might reform the Methane, and produce Hydrogen, but a byproduct might be an oil that the fungi could digest.

https://www.bing.com/videos/search?q=mu … ORM=VRDGAR

Of course if you reform Methane into Hydrogen and Oil, then for the fungi to eat the oil, they will need Oxygen.  Perhaps this could be extracted from the tiny amount in the Martian atmosphere.  Or I have read that greenhouses will produce excess Oxygen.

Mushroom nutrition for humans:
http://www.fitday.com/fitness-articles/ … anked.html

Mushroom Calories/Protein:
https://www.caloriecount.com/calories-mushrooms-i11260
Quote:

Nutrition Facts
Serving Size 1 cup, pieces or slices (70 g)
Per Serving
% Daily Value*
Calories 15

Calories from Fat 2
Total Fat 0.2g
0%
Saturated Fat 0g
0%
Polyunsaturated Fat 0.1g
Monounsaturated Fat 0g
Cholesterol 0mg
0%
Sodium 4mg
0%
Potassium 222.6mg
6%
Carbohydrates 2.3g
1%
Dietary Fiber 0.7g
3%
Sugars 1.2g
Protein 2.2g

Vitamin A 0% · Vitamin C 3%
Calcium 0% · Iron 11%

And unlike plants no photons required.

One really possibly cool aspect of this is that you could grow green slime in a very low pressure greenhouse, and feed the green slime to your livestock the fungi, which produce mushrooms, and the eat the mushrooms.

Most of our other livestock candidates will not eat green slime, or might be poisoned by it.

Polar Seas (Fresh water most likely).

Yes domes are one idea for polar seas, and absolutely it would be formidable task.

Certainly being saved for much later than the first colony, unless some new technology shows up as practical.

The list of possible options to facilitate the melting of a polar sea (North), or a chain of very large lakes (South) is rather long I feel.

1) Spacenuts Dome.
2) Ground Based Heliostats, that few people here are comfortable with yet (In truth CO2 ice could damage them, so warm the planet above that temperature before you can apply ground based Heliostats in a practical manner).  In the use of ground based heliostats the objective would be to inject heat under the ice, and to use an ice layer to insulate a body of water produced.
3) Greenhouse gasses.  (It is hoped that greenhouse gasses alone can melt the polar ice caps.  But let us remember that the Earth has a very good greenhouse effect, an yet our polar ice caps are only partially melted.  The north pole is actually more melted I think by the flow of water from warmer regions).
4) Orbital Heliostats.  Typically this seems to imagine warming the ice caps at the surface of them so much that CO2 evaporates, or even the polar ice caps are dissipated
5) Fission power plants.  I would think that Antius would like this one.  If you have a fission power system as the French apparently have successfully managed, there can be a symbiotic relationship to it using the Polar ice caps.  Obviously.  Here again you inject the heat into a body of water protected from loss of heat by a layer of ice.
6) Fusion power, if attainable.  Much the same as #5, but with less likelihood of making the polar ice cap waters radioactive.
7) Serpentization. (http://www.space.com/33294-enceladus-ma … -city.html) This has to be taken "With a grain of salt".  Not sure if Serpentization generates that much heat.  Probably it does generate significant heat.  But it can also produce salts and Hydrocarbons.  Fracking at the bottom of a polar sea may stimulate Serpentization processes.
8) Introduce O2 and CO from the atmosphere of Mars into the waters, allow microbes to digest it.  This would produce heat.  However, the amount of O2 and CO in the atmosphere is very trace, being produced by photolysis of the atmosphere under the suns U.V. spectrum.  However if a efficient method to extract those gasses from the Martian atmosphere could be invented, then much energy could be introduced into a Martian polar sea, and according to this notion also producing a biosphere of microbes activated by the introduced O2 and CO.
9) Water canaled to the equator, O2 and Methane/H2 piped to the poles.  Using Photolysis, or electrolysis, these gasses produced at the equator from water canaled to the equator could be pumped into the polar seas, to feed organisms, and so produce heat.  (Think moist haystack that catches fire).
10) Forget the water canaled to the equator.  Just split CO2 into O2 and CO at the equator, and pipe that to the poles, in order to feed a microbe community under the ice with O2 and CO, thus to produce "Haystack Heat".

Then if you managed to produce a polar sea of fresh water (Mostly fresh), and could keep the insulating ice surface thin enough during the summer, you might anticipate that photons will enter the liquid waters, and you might have photo life in the ice covered bodies of water as well.

*More thoughts about orbital Heliostats.
I am tired and will not make the conversions.  Water at 32 degrees F lighter than water at 39 degrees F.

Put some floating objects on the polar ice cap that are lighter than liquid water but heavier than ice.  Make them black.  Focus your orbital mirrors on those locations.

1 Square Mile?

The heliostat light passing through an "Ice window" hitting the black objects, heating the water to 39 degF.  That water sinking below the 32 degF water which is adjacent to the "Ice window.

So you drill/melt a hole all the way down to the bedrock of the polar ice caps.  And that body of water can be expanded to include the whole reservoir of the Polar ice cap.

Granted, the effort to have orbital heliostats that do this, focusing on the polar ice caps, is a very, very hard task.

Enough.  Thanks for considering my input.  I am tired.  Nite nite.

Last edited by Void (2016-12-03 22:20:44)


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#13 2019-01-15 19:04:29

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: Heliostats on Mars, and other worlds.

Typically we are talking molten salts for heat retention but maybe this would be the ticket for mars:

louis wrote:

Looks like we might have a technical solution to intermittency...

https://www.sciencedaily.com/releases/2 … 171913.htm

I'm guessing that the way to produce complete energy security is to improve insulation so you can keep the superheated silicon liquid over several days.  Wikipedia says of thermal energy storage that "With proper insulation of the tank the thermal energy can be usefully stored for up to a week". 

They article indicates one unit could serve 100,000 people. That's about 3000 to serve all homes in the USA. Maybe double that for industry as well - 6000. But obviously fewer than that number would be required.

If you also remember that electric car batteries will also (with incentives) be available as storage for the grid, then I think we can see a way forward to a renewable energy world comprising solar, wind, energy from waste, hydro, wave power, geothermal, sea current, tidal power, bio fuels,  methane (produced from solar and wind in times of over production) ,  transcontinental grids, thermal energy storage,  chemical battery storage and pumped hydro storage. During times of low energy generation from wind and solar, there will be ramped up production from energy from waste, bio fuels and methane plus use of stored energy.

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#14 2019-01-15 20:21:52

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Heliostats on Mars, and other worlds.

That is a very encouraging device SpaceNut, just as they present it.
Of course Heliostats may or may not be used to help pump it up.  In the end whatever gets the job done best.

……

Believe it or not I have posted about distantly similar methods.  Not proven to be sure.

For instance if you could make a cone shaped cave, say in rock or just maybe in a salt dome.  You might heat the ceiling to incandescence.  I have always considered stopping at red.  I believe that since some microbes can do oxidative photosynthesis even with near infrared, the that wavelength up to red could be sufficient for a biosphere.  Of course then you might be concerned about heat radiating down to the garden you might have below.  But if you put it into a greenhouse and perhaps filled the rest of the cave with a mix of greenhouse gasses, maybe the short infrared can be blocked.  If not good enough then fill the greenhouse with water, and circulate cooling water into it.

I believe that with GM it should be possible to make garden plants that can use infrared and red light.  Maybe you would also add some blue from LED's but I would like to skip that.

…..

If gardens are not possible, then I did think that the cave could have high temperature solar cells in it.  So, in that case how do you heat the caves upper part?  Well I had thought that Incandescent Martian gasses could be circulated through it from a focus from Heliostats on the surface.  If that worked then you basically change the Mars surface spectrum which is hostile to life into the cave spectrum which might be suitable to life, or at least solar cells.  This would give you your 24/7 power except for when global dust storms occur.

…..

Another device I have mentioned might be similar, where you have a metal cone sitting on the surface of Mars.  Your heliostats heat the top of the cone to incandescence which may transfer to the interior and shine like a sun.  In this case there would not be much storage of energy, so the hope would be to adapt it to gardens.  For instance your seaweed you mentioned elsewhere.  A water plant would be very good, as again you could circulate fresh cool water from a reservoir into the bottom of the cone, to keep the crop cool.  And then the heated water circulated out of the cone could heat a reservoir which was ice covered most likely.  And so store energy.  Vapors coming off of the water inside the cone could be condensed on unheated portions of the cone walls, to produce fresh water of some use.

……

But I am perfectly happy to return to the item you posted about, it seems like a very nice tool.

I prefer to have as many tools as possible.  Making them better is also nice.

Done.

Last edited by Void (2019-01-15 20:35:00)


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#15 2019-01-16 12:39:48

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Heliostats on Mars, and other worlds.

SpaceNut curiously, this has appeared, and just might fit into some Mars purpose.
https://phys.org/news/2019-01-scientist … rared.html
Quote:

Their approach, known as triplet fusion upconversion, involves a chain of processes that essentially fuses two infrared photons into a single visible light photon. Most technologies only capture visible light, meaning the rest of the solar spectrum goes to waste. Triplet fusion upconversion can harvest low-energy infrared light and convert it to light that is then absorbed by the solar panels. Visible light is also easily reflected by many surfaces, whereas infrared light has longer wavelengths that can penetrate dense materials.

Read more at: https://phys.org/news/2019-01-scientist … d.html#jCp

Of course the proposed medical applications will also be important on a planet which will have an as yet undefined power to promote cancer in humans.

While I think it will ultimately be possible to GM crops to work with near infrared and red light, and to tolerate perpetual lighting 24/7, this new technique may offer some real benefits both for gardening underground and of course for human psychological happiness.

If this technology is affordable and practical, then heat stored in rock, molten salt baths, and the silicon device you recently posted about, may change long wave infrared into more useful wavelengths.  Both to stimulate solar panels on desire and to grow gardens in caves or underwater.

Obviously caves and artificial tunnels and indeed pseudo stone structures on the surface, made of Boring Company tailings in part, might all host gardens which can have day durations similar to an Alaskan summer.  Midnight sun of course.

https://www.hcn.org/issues/49.16/agricu … y-possible
Quote:

Alaska’s history is littered with failed agricultural enterprises. Around 1883, explorers noted that seeds planted in Arctic Alaska could be harvested in just 27 days because of the ’round-the-clock sunlight. In 1912, industrious farmers in the state’s interior produced the equivalent of $2.4 million worth of produce. The following year, it snowed in August, ruining crops.

Of course if you are in a cave, tunnel, or underwater, frost is not that much of a risk.
So apparently they like a mix of Volcanic materials and organic matter for soil:
Quote:

Medley believes the 12-hour days are worth it. Thanks to built-up organic matter and ash from nearby volcanoes, locals say that Homer has some of the best soil in the Northern Hemisphere.

I guess I am thinking the organic materials could come in part from ice covered reservoirs where chemosynthesis is used to promote a plankton.  That plankton falling to the floor of the reservoir or being harvested could grow a crop of mushrooms, and then the mushroom compost, castings, can serve to mix with volcanic materials I suppose.

I guess this will depend on if that chemical process can effectively and for a reasonable cost, provide lighting on demand from stored heat.

Done.

Last edited by Void (2019-01-16 13:00:36)


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#16 2019-01-16 19:45:39

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: Heliostats on Mars, and other worlds.

Materials to shft the color of the light that comes out of a ray of light sent in has been known for a period of time as lasers use the effect to make green If I recall correctly.

Thermal energy is also shared at the low end of the red spectrum as well

Spectrum+of+electromagnetic+radiation?format=1000w

infrared.jpg

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#17 2019-01-17 18:01:17

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: Heliostats on Mars, and other worlds.

A metal that is heated to a high temperature can also glow with a color. For instance, a metal with temperature around 900 degrees Fahrenheit (500 degrees Celsius) is about a faint red glow, while metals with temperature above 2500 F (1400 C) glow hot white.
https://en.wikipedia.org/wiki/Thermal_radiation

http://coolcosmos.ipac.caltech.edu/page … s_infrared

http://people.csail.mit.edu/jaffer/Color/Heat/

https://en.wikipedia.org/wiki/Black-body_radiation

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#18 2019-01-17 18:39:51

tahanson43206
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Registered: 2018-04-27
Posts: 16,752

Re: Heliostats on Mars, and other worlds.

For Void ... thank you for this discovery of the IR fusion technique ... It seems (at first reading) to have significant potential value.

To try to make your post easier to find, I'm adding some search terms:

SearchTerm:IRfusion
SearchTerm:InfraRed


Void wrote:

SpaceNut curiously, this has appeared, and just might fit into some Mars purpose.
https://phys.org/news/2019-01-scientist … rared.html
Quote:

Their approach, known as triplet fusion upconversion, involves a chain of processes that essentially fuses two infrared photons into a single visible light photon. Most technologies only capture visible light, meaning the rest of the solar spectrum goes to waste. Triplet fusion upconversion can harvest low-energy infrared light and convert it to light that is then absorbed by the solar panels. Visible light is also easily reflected by many surfaces, whereas infrared light has longer wavelengths that can penetrate dense materials.

Read more at: https://phys.org/news/2019-01-scientist … d.html#jCp

Done.

(th)

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#19 2019-01-21 19:52:11

tahanson43206
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Registered: 2018-04-27
Posts: 16,752

Re: Heliostats on Mars, and other worlds.

Void,

Upon reading the article you found a second time, I note that the investigators were primarily interested in helping to destroy cancer cells while avoiding damage to healthy cells.  I gather that their notes about other applications are secondary for their mission.

However, I am hoping my interpretation may have merit, and invite others on the forum to provide their insights.

Thermoelectric devices are in use to generate electricity given a source of heat and availability of a heat sink.  The greater the difference of temperature, between the heat source and the heat sink, the greater the current which can be caused to flow.   In space, a method of releasing thermal energy from a vehicle is radiation in infrared wavelengths.

The system described in the paper you found appears to use a chemical process to accept low energy IR photons as input, and to (somehow) cause a higher energy photon of visible light to be generated.

The efficiency of this process would (probably) not be a concern in the treatment of cancer.  Any infrared radiation not consumed by the conversion system would (presumably) spend itself in gentle heating of tissue.

However, for a space energy capture situation, the efficiency of the process would be of interest.

Never-the-less, it would seem (to me at least) worth investigating the possibility that the system efficiency of a thermoelectric power generator might be increased by capturing waste heat in the form of infrared radiation, converting it to visible light, and then capturing THAT light with photovoltaic cells.

(th)

Void wrote:

SpaceNut curiously, this has appeared, and just might fit into some Mars purpose.
https://phys.org/news/2019-01-scientist … rared.html
Quote:

Their approach, known as triplet fusion upconversion, involves a chain of processes that essentially fuses two infrared photons into a single visible light photon. Most technologies only capture visible light, meaning the rest of the solar spectrum goes to waste. Triplet fusion upconversion can harvest low-energy infrared light and convert it to light that is then absorbed by the solar panels.
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#20 2019-01-21 20:58:49

SpaceNut
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From: New Hampshire
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Posts: 28,747

Re: Heliostats on Mars, and other worlds.

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#21 2019-01-22 05:07:18

elderflower
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Posts: 1,262

Re: Heliostats on Mars, and other worlds.

Thermoelectric devices are heat engines and therefore are subject to the efficiency limitations of these. In particular you cannot exceed the thermal efficiency of a Carnot engine working between the same temperatures.
The above limits do not apply to electrochemical devices, like fuel cells, which have their own limits. These are not so restricting as the Carnot cycle law.

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#22 2019-01-22 12:32:03

Void
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Registered: 2011-12-29
Posts: 6,976

Re: Heliostats on Mars, and other worlds.

Various comments.  Interesting.

The potential to join two lower powered photons into one photon of a higher energy level, will require more information to determine it's possible utilities.

While I think the medical uses could be very important in space, I am also interested in the stored power utility that is hinted at;

2 infrared photons > 1 visible photon > Solar Panel.

But I would also be interested in;

2 infrared photons > 1 visible photon > photosynthesis.

One of the values of such a process is that you could perhaps store heat at a lower temperature, and yet then somewhat be able to release the energy on demand, (Perhaps), to stimulate the production of electricity and/or photosynthesis.  This might allow you to control the lengths of the days that plants would experience.

But at this point, much more needs to be learned.

……

As for efficiency, yes that matters, but so does capability.

For instance, I could say that modern humans with their big brains are not efficient, perhaps not as efficient as homo erectus.

But they are more capable.  The predators of our ancestors and our ancestors material needs, suggest that the modern human mind is suited to prosper from capability more than efficiency.

I might propose, (Without proof),  that homo erectus had high levels of communication, and so a group of 6 individuals may have functioned as something like a bee hive mind or a more highly communicative wolf pack.  In certain ways more efficient than a group of 6 individuals linked by communication with modern human brain/minds. 

The task is what determines what makes sense in the above.  If your plan is to run prey animals in circles by doing a hand off between the 6 homo erectus individuals, then the homo erectus will eventually replace the modern humans, as the modern humans are burdened by excessively large and calorie demanding brain/minds.  But if a greater human capability is useful, then 6 modern human brain/minds might win out.

The contest would work this way.  In theory 6 homo erectus minds linked by communications and being each a specialist of some part of the equivalent of part of a modern human mind, could on the cheep create the intelligence of one single modern human brain/mind.  And so I do not rule out that they could collectively have a hive consciousness equivalent to one modern human mind and they might eventually solve many of the problems we supposedly can.  But communications by mouth-ear or hand-eye are slow relative to communications within a modern human mind.  So while they may have the capability to mimic one human mind over long time spans, the modern humans have 6 individuals who can teach and learn from each other by mouth-ear and hand-eye communications, and yet internally each modern brain/mind is equivalent to a hive of homo erectus, but internal communications between the brain sections are much quicker.

So words like efficient, effective, capable, are somewhat wishy washy.

Indeed excessive reliance on group think often gums up things, as the individuals should be seeking to use their minds more internally, and to rely on interpersonal communications for more useful things like teaching and learning.  (Programming sharing).

This I think, is a vast mistake that humans made in the last few centuries where they over emphasized communicative intelligence, and during the industrial age developed a college system which in reality is a method to Castrate/Lobodomize the minds of the servant classes.  Turning them into servant robots.

There are two obvious types of manipulation.  To manipulate objects, and to manipulate people.   smile

However I might not like aspects of what was done or what is being done, I am not ready to overturn the game board.  The process got us here to a new potential.  I am not ready to cause more damage than good by recommending radical changes.  Yet.

But I did froth at the mouth!

……

Heliostats/Robots

It is interesting that in the age of robots and the even stronger coming age of robots, there is so much resistance to the ideas of robot heliostats on Mars, or the idea of telepresence robot avatars on the surface of Mars.  Just incredible how much this not accepted as a useful method.

Anyway I think that normal use of heliostats will involve a collection of such.  How much "Brain" power do they need?  I would say you don't need a super computer.  They have a limited task.  Deflect sunlight from a moving object the Sun, to a target(s).

So in my world, I see them often working in parallel groups but during the day having potentially different targets.  I don't see much reason to add more calculation ability than needed.  In fact on version I am rather fond of has a central observer/calculator near a target(s), that can see each heliostat and knows the identity of each and all of them.  It can "See" how they are pointing, and give instructions for them to change their pointing status.  This is somewhat in contrast to those who want robot/computers that will be smarter than us.

I would rather have a bee community that gives us "Honey" not "Stings".

As for the target(s).  I suggest that perhaps a tower made of a cone of bricks but with a metal mast on top would be interesting.

Perhaps various types of solar panels on that cone.  Perhaps a high temperature oven/boiler on the metal mast.

During the course of a Martian day, in the morning and afternoon, perhaps the main objective might be to satisfy electrical power demands, so that would be the task of most or all of the heliostats.  Deflect an appropriate number of photons to the solar panels.  These might even be high temperature solar panels that can use most wavelengths of light.  During hours adjacent to high noon, however it might be useful to divert some photons to the oven/boiler.  Maybe you just want to squirt steam into the atmosphere.  Maybe you want to bake something.  Maybe you want to heat up compressed CO2 or Martian atmosphere, and inject that heated gas into underground reservoirs.  Those reservoirs might store energy as heat, pressure, salinity differentials of brines or whatever.

So that is how I think about it.  We are planning to have sophisticated robots in our lives in the next 10, 20, 30 years, here on Earth, why can't we contemplate relatively low intelligence heliostat robots on Mars to give us material gain?

And for that matter why so much resistance to telepresence avatars?

Sci Fi of the 60's and 70's got things locked down?  Are we a dogmatic religion of old Sci Fi?

Done.

Last edited by Void (2019-01-22 13:32:54)


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#23 2019-01-22 14:11:34

tahanson43206
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Registered: 2018-04-27
Posts: 16,752

Re: Heliostats on Mars, and other worlds.

For Elderflower,

Thanks for your reminder of Carnot ... I suspect (although am not sure) you brought this up because you might have thought I was proposing the efficiency of a thermoelectric generator might be changed somehow.  I am NOT suggesting any changes to the generator.  It does its thing, which results in waste heat energy currently delivered to the Universe.

However, the generator is one system in a larger system, which is the space craft.

There are many instances of heat generators producing work and delivering waste heat to the environment, much to the delight of those downstream who can and do benefit.  A typical example of beneficiaries are fish living in the warm waters downstream from a power plant, although there are reported to be instances of humans enjoying waste heat from municipal power plants.

In the case of my inquiry, if the 2 IR to 1 visual photon idea is ** real **, then ( I presume ) it could be harnessed to consume some of the waste energy from the thermoelectric generator.

For Void ...

Thank you for developing this idea further.  Since low grade heat sources abound on Earth, and (apparently) elsewhere in the Solar System, a capability of harvesting higher energy from low grade sources ought to be valuable wherever such sources are found.

I am assuming that the efficiency of conversion is NOT 100 percent.  Real world efficiency might be as low as 25%, by the time that four IR photons have been consumed in the process of delivering one high grade photon.   However, given the abundance of volcanic lava flows on Earth, and in selected locations in the Solar System, such low efficiency would not (or in my opinion, should not) impede development of the capability.

(th)

Void wrote:

Various comments.  Interesting.

The potential to join two lower powered photons into one photon of a higher energy level, will require more information to determine it's possible utilities.

While I think the medical uses could be very important in space, I am also interested in the stored power utility that is hinted at;

2 infrared photons > 1 visible photon > Solar Panel.

But I would also be interested in;

2 infrared photons > 1 visible photon > photosynthesis.

One of the values of such a process is that you could perhaps store heat at a lower temperature, and yet then somewhat be able to release the energy on demand, (Perhaps), to stimulate the production of electricity and/or photosynthesis.  This might allow you to control the lengths of the days that plants would experience.

But at this point, much more needs to be learned.
...
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#24 2019-01-22 15:52:30

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,752

Re: Heliostats on Mars, and other worlds.

Void ...

In attempting to find out if the 2 IR to 1 visible photon phenomenon is "real" I asked Mr. Google for assistance.

To my surprise, research from 2014 showed up.  Work done at institutions in the general area is reported:

https://www.nature.com/news/photons-dou … le-1.16459

One discovery is that (apparently) the human eye is capable of performing photon energy translations, although I came away thinking that more work needs to be done to verify the hypothesis described.

(th)

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#25 2019-01-22 17:26:20

Void
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Registered: 2011-12-29
Posts: 6,976

Re: Heliostats on Mars, and other worlds.

tahanson43206...

Yes it is an item to be interested in.  Perhaps further mention of it will occur in the future, and that will better define any real potentials.

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