Author Topic: Power options for a Mars settlement  (Read 150306 times)

Offline DistantTemple

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Re: Power options for a Mars settlement
« Reply #500 on: 04/19/2018 08:08 pm »
My speculation... A NASA team of several astronauts, one or two Kilopower reactors.... on the first Human mission.
Quote from: john smith 19
That said I think they'd expect SX to pay something per unit to offset some of those costs.
Not "payment" as such, but the opportunity for NASA to have a key, valued role in the expedition, and not be just passengers, or scientist/explorers, or labour for SX to deploy. The NASA personnel would have their own expertise, and tasks to perform, to install connect maintain and evaluate the reactors.
Of course SX can have sufficient solar panels and batteries to cover the shortfall if the nulcear takes a while to come online... 
Of course the NASSA contingent could get stuck into everything else when their "baby" is happy.
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Offline speedevil

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Re: Power options for a Mars settlement
« Reply #501 on: 04/19/2018 09:50 pm »
My speculation... A NASA team of several astronauts, one or two Kilopower reactors.... on the first Human mission.
Quote from: john smith 19
That said I think they'd expect SX to pay something per unit to offset some of those costs.
Not "payment" as such, but the opportunity for NASA to have a key, valued role in the expedition, and not be just passengers, or scientist/explorers, or labour for SX to deploy. The NASA personnel would have their own expertise, and tasks to perform, to install connect maintain and evaluate the reactors.
Of course SX can have sufficient solar panels and batteries to cover the shortfall if the nulcear takes a while to come online... 
Of course the NASSA contingent could get stuck into everything else when their "baby" is happy.

Nuclear is perhaps the hardest capability for a private company to develop. I wonder if the potential of spinning this as 'a vital component of' could limit NASA intrusion into the design of the core mission.

If it can't, it may be best not to take NASA money at all for any marsbase, and only offer contracted kilos on the ground.

Offline DistantTemple

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Re: Power options for a Mars settlement
« Reply #502 on: 04/19/2018 10:08 pm »
My speculation... A NASA team of several astronauts, one or two Kilopower reactors.... on the first Human mission.
Quote from: john smith 19
That said I think they'd expect SX to pay something per unit to offset some of those costs.
Not "payment" as such, but the opportunity for NASA to have a key, valued role in the expedition, and not be just passengers, or scientist/explorers, or labour for SX to deploy. The NASA personnel would have their own expertise, and tasks to perform, to install connect maintain and evaluate the reactors.
Of course SX can have sufficient solar panels and batteries to cover the shortfall if the nulcear takes a while to come online... 
Of course the NASSA contingent could get stuck into everything else when their "baby" is happy.

Nuclear is perhaps the hardest capability for a private company to develop. I wonder if the potential of spinning this as 'a vital component of' could limit NASA intrusion into the design of the core mission.

If it can't, it may be best not to take NASA money at all for any marsbase, and only offer contracted kilos on the ground.
I imagined that NASA probably wouldn't be able to transfer such technology easily or quickly, and this arrangement would give SX access to Kilopower.

It is true that power (and heat) from Kilopower reactors would be extremely useful, as people have said above, for ISRU, baseload, mining water by melting... etc.

NASA can claim to be making an important contribution, and not be publicly embarrassed by being shut out of the project. Plus its a nicer way to work (together).
We can always grow new new dendrites. Reach out and make connections and your world will burst with new insights. Then repose in consciousness.

Offline Elmar Moelzer

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Re: Power options for a Mars settlement
« Reply #503 on: 04/20/2018 01:02 am »
I hate to be pessimistic, but we've been hearing about fusion break even for decades. It would be great if it happened next year, but I wouldn't be surprised if it doesn't happen in twenty years.
A lot of the delays were because of the notoriously low funding for anything but tokamaks and those things are big and complicated and expensive mega projects that take a long time to develop. A lot has changed in the past 20 years, however and new designs and ideas have emerged along with new enabling technology.
One can not look back to predict the future. I mean, a few years ago, none of us would have worried about power options for a Mars settlement or would have expected fully reusable Mars space ships any time soon and look where we are now!

Since Musk wants to land the first BFS on Mars in less than a decade, we need to be discussing what can be ready to deploy very soon. Even if there's a big fusion success next year, production power reactors won't be ready for the initial settlement.
That is probably true, but then a success like that would result in a lot of interest from many parties (including NASA) and a lot of cash flow. All that could accelerate development a lot. Again, look what happened with RLV development in the last 10 years! Plus, even if there is no reactor ready for Mars 15 years from now, the colony will still be growing (assuming that enough people want to go) and so will the power requirements. They can start out with solar and batteries initially and then switch to fusion, once it becomes available.

Online Robotbeat

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Re: Power options for a Mars settlement
« Reply #504 on: 04/20/2018 01:51 am »
This sounds really familiar. Okay, beer bet, then. No breakeven by end of 2019.
I am not a betting man and this is a very hard task. So I would not make that bet myself, but for the fun of it, I will hold that bet, if only to maybe convince you to visit me in Michigan some day to claim that beer ;)
Okay, so what are the terms? No Helios scientific breakeven before end of 2019 UTC.

I consider scientific breakeven to be total input power equal to power generated by fusion. That's easier than engineering breakeven, which takes into account the efficiency of converting the heat to electricity.


What I am NOT referring to is just input power to the pellet. It has to be wall-plug input power being equal to the heat of the generated fusion. Deal? If so, I will send an email to emailfuture.com to remind myself on January 1st, 2020.

Terms are: beverage or beer (value not to exceed $5 or so) to the winner, must be redeemed in person.
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Offline paramedikisto

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Re: Power options for a Mars settlement
« Reply #505 on: 04/20/2018 02:17 am »
Has anyone considered salvaging and using the nuclear reactors currently in orbit?  The Russians orbited over 30 reactors, most producing 2-3KW, and a couple larger ones that produced about 6KW (all electrical, the reactors produced much more thermal energy...which is also useful).  There was also SNAP-10A that the US launched, but it only produced about 500W.

My thought is that the reactors, or at least the cores (which were mostly ejected into a graveyard orbit) could be salvaged and transported to Mars, where the core or  even just the fuel rods could be placed into a reactor, ideally one specially constructed to accept multiple cores so as to obtain a greater output.  Doesn't seem like that difficult of an engineering task.

The advantage would be that these reactors get removed from orbit around the Earth, where they are a hazard, and will (after thousands of years) eventually decay and reenter the atmosphere.  There is also the advantage of not having the huge headache of launching nuclear material, and since under the OST the reactors are still property of Russia, they can be sold off by the government.


Offline Ludus

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Re: Power options for a Mars settlement
« Reply #506 on: 04/20/2018 04:13 am »
I hate to be pessimistic, but we've been hearing about fusion break even for decades. It would be great if it happened next year, but I wouldn't be surprised if it doesn't happen in twenty years.
A lot of the delays were because of the notoriously low funding for anything but tokamaks and those things are big and complicated and expensive mega projects that take a long time to develop. A lot has changed in the past 20 years, however and new designs and ideas have emerged along with new enabling technology.
One can not look back to predict the future. I mean, a few years ago, none of us would have worried about power options for a Mars settlement or would have expected fully reusable Mars space ships any time soon and look where we are now!

Since Musk wants to land the first BFS on Mars in less than a decade, we need to be discussing what can be ready to deploy very soon. Even if there's a big fusion success next year, production power reactors won't be ready for the initial settlement.
That is probably true, but then a success like that would result in a lot of interest from many parties (including NASA) and a lot of cash flow. All that could accelerate development a lot. Again, look what happened with RLV development in the last 10 years! Plus, even if there is no reactor ready for Mars 15 years from now, the colony will still be growing (assuming that enough people want to go) and so will the power requirements. They can start out with solar and batteries initially and then switch to fusion, once it becomes available.

The Helion Fusion Engine concept has the great virtue that if it works, itís ready to scale in the most effective way, as a mass produced compact 50 MW reactor. The speed that Elon has moved from PowerPoints to giant mandrels for carbon fiber on the BFR has rattled my cynicism about hopeful tech. A 50MW fusion reactor popping up that fits perfectly in that BFR would be just what the Heinlein novel version of the 2020ís calls for.

Mars even turns out to be oddly favorable for deuterium.
https://www.newscientist.com/article/dn22572-heavy-hydrogen-excess-hints-at-martian-vapour-loss/
« Last Edit: 04/20/2018 04:37 am by Ludus »

Offline john smith 19

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Re: Power options for a Mars settlement
« Reply #507 on: 04/20/2018 07:00 am »
Has anyone considered salvaging and using the nuclear reactors currently in orbit?  The Russians orbited over 30 reactors, most producing 2-3KW, and a couple larger ones that produced about 6KW (all electrical, the reactors produced much more thermal energy...which is also useful).  There was also SNAP-10A that the US launched, but it only produced about 500W.

My thought is that the reactors, or at least the cores (which were mostly ejected into a graveyard orbit) could be salvaged and transported to Mars, where the core or  even just the fuel rods could be placed into a reactor, ideally one specially constructed to accept multiple cores so as to obtain a greater output.  Doesn't seem like that difficult of an engineering task.

The advantage would be that these reactors get removed from orbit around the Earth, where they are a hazard, and will (after thousands of years) eventually decay and reenter the atmosphere.  There is also the advantage of not having the huge headache of launching nuclear material, and since under the OST the reactors are still property of Russia, they can be sold off by the government.
Welcome to the site.

I think you'll find the Russian reactors were in the 10s of Kws. They wanted to run ocean surveillance radar from them. This is pretty thirsty.

As for recovering the cores and recyling the fuel. Let's see.

They are in high orbit. So you'll need significant delta v to find and catch them.

They will be intensively radioactive as they are strong neutron emitters.  During construction you could handle the fuel elements of the SNAP 10a with nothing but rubber gloves (watch the videos of it being assembled). A BFS which took one aboard (after running) however would be strongly  irradiated.

You now have to break the (different) designs down and extract the actual enriched fuel. No one's developed that technology WRT these designs. Never designed for disassembly. Either need high energy processes or aggressive chemicals, even if you just take them to Mars so you can do this in something like Earth gravity.

It sounds very wasteful, but IRL it's simpler and easier to do things this way.
However for Mars a sustainable nuclear programme would be a very different proposition.

PWR's are the most common reactor design on Earth. They make great power sources for ICBM carrying submarines operated by a state with a navy and a substantial nuclear weapons programme. But Mars has no free bodies of water. Those design choices are not really very relevant there.  Especially the one about the availability of enriched Uranium as fuel.
« Last Edit: 04/20/2018 11:38 am by john smith 19 »
BFS. The worlds first Methane fueled FFORSC engined CFRP stainless steel structure A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP stainless steel structure booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C apply. Believe no one. Run your own numbers. So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

Online josespeck

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Re: Power options for a Mars settlement
« Reply #508 on: 04/20/2018 09:44 am »
74,000,000 square miles are used for agriculture on Earth. I really don't think a few square miles for solar (which is just a kind of agriculture, just using photovoltaics instead of photosynthesis) is going to be that much of a problem for Mars (which has about the same land area as Earth). The area argument against solar is tired and not actually true when judged in proportion to other uses of land (particularly agriculture). And this applies much more strongly on Mars.

From a mass perspective, solar is superior to nuclear on Mars. And solar+batteries are a very good solution.

NO.

http://www.fao.org/fileadmin/user_upload/newsroom/docs/en-solaw-facts_1.pdf

Offline speedevil

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Re: Power options for a Mars settlement
« Reply #509 on: 04/20/2018 10:08 am »
74,000,000 square miles are used for agriculture on Earth. I really don't think a few square miles for solar (which is just a kind of agriculture, just using photovoltaics instead of photosynthesis) is going to be that much of a problem for Mars (which has about the same land area as Earth). The area argument against solar is tired and not actually true when judged in proportion to other uses of land (particularly agriculture). And this applies much more strongly on Mars.

From a mass perspective, solar is superior to nuclear on Mars. And solar+batteries are a very good solution.

NO.

http://www.fao.org/fileadmin/user_upload/newsroom/docs/en-solaw-facts_1.pdf

NO?
The actual cultivated area is around 7 million, not 70 million (which is the total land area).
Is this your only comment?

Online Robotbeat

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Re: Power options for a Mars settlement
« Reply #510 on: 04/20/2018 12:38 pm »
74,000,000 square miles are used for agriculture on Earth. I really don't think a few square miles for solar (which is just a kind of agriculture, just using photovoltaics instead of photosynthesis) is going to be that much of a problem for Mars (which has about the same land area as Earth). The area argument against solar is tired and not actually true when judged in proportion to other uses of land (particularly agriculture). And this applies much more strongly on Mars.

From a mass perspective, solar is superior to nuclear on Mars. And solar+batteries are a very good solution.

NO.

http://www.fao.org/fileadmin/user_upload/newsroom/docs/en-solaw-facts_1.pdf
Thanks for making my point. About 37 percent of the world is used for agriculture in total, if you include grazing. I accidentally used total surface of the Earth instead of just land area, but thanks for providing data that backs up my point.
« Last Edit: 04/20/2018 12:47 pm by Robotbeat »
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Offline Elmar Moelzer

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Re: Power options for a Mars settlement
« Reply #511 on: 04/20/2018 04:56 pm »
Okay, so what are the terms? No Helios scientific breakeven before end of 2019 UTC.

I consider scientific breakeven to be total input power equal to power generated by fusion. That's easier than engineering breakeven, which takes into account the efficiency of converting the heat to electricity.
I think that they have a chance to achieve scientific break even. There are a couple of caveats. It could be that Helion will only use D+D for their tests. Their Fusion Engine is supposed to extract He3 from the D+D- reaction exhaust and feed it back into the reactor as fuel for the following shot. The problem is that D+D releases less energy than D + He3 would and the extraction system might not be part of this test reactor yet. Since He3 is also very expensive, they might only do D+D shots for their experiments and then convert the resulting energy release of that into what it would have been with D+ He3, at least until they have fully optimized everything. Unlike going from D+D to D+T, going from D+D to D+He3 is actually easier, because the neutron wall loading is a lot less (among other things) and they won't need FLiBe tanks and all those complicated things that are needed for D+T burning Tokamaks. It is merely a cost saving measure if they don't do that right away.
So, I would like to include that caveat in the bet: Scientific break even with D+D result converted to D+He3 result. If you are OK with that.

Offline Elmar Moelzer

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Re: Power options for a Mars settlement
« Reply #512 on: 04/20/2018 05:01 pm »
The Helion Fusion Engine concept has the great virtue that if it works, itís ready to scale in the most effective way, as a mass produced compact 50 MW reactor. The speed that Elon has moved from PowerPoints to giant mandrels for carbon fiber on the BFR has rattled my cynicism about hopeful tech. A 50MW fusion reactor popping up that fits perfectly in that BFR would be just what the Heinlein novel version of the 2020ís calls for.

Mars even turns out to be oddly favorable for deuterium.
https://www.newscientist.com/article/dn22572-heavy-hydrogen-excess-hints-at-martian-vapour-loss/
Yes, that is what I have been thinking about too. Plus, the direct power conversion solves a lot of problems that would come with steam cycles. I believe that a single Helion reactor could be transported to Mars in anywhere between one and three BFS launches, depending on a few factors. Also worth noting that these reactors need so little fuel that you could send fuel for years along with any of these 3 launches and it would make no measurable difference in weight and volume.
« Last Edit: 04/20/2018 05:02 pm by Elmar Moelzer »

Offline AC in NC

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Re: Power options for a Mars settlement
« Reply #513 on: 04/20/2018 08:57 pm »
Thanks for making my point. About 37 percent of the world is used for agriculture in total, if you include grazing. I accidentally used total surface of the Earth instead of just land area, but thanks for providing data that backs up my point.

It's a good point.

At this point long removed from the effort, I won't attest to the whether I did it right and was accurate in calculations.  However, I once was trying to spitball the cost of a massive solar project as a layman's perspective on what we could have alternatively done with certain large government expenses since 2000 in certain troublesome areas.

My recollection is that I validated a variety of numbers from various sources and did a back-of-the-napkin calculation that the entire US annual energy electricity production could be replicated in a square solar-field 30 miles on a side (900 sq mi).  As I recall, this accounted for US Electrity Consumption, then-current Efficiency, reasonable assumption about Solar hours/day and weather, but perhaps not accounting for panel angle-to-the-sun and transmission losses.

The operative point I think being that it easier to do a lot with a little groundspace than you might expect.

As an aside, I think the cost of those 900 sq mi of Solar was significantly higher than the expenditures I was comparing against, but it wasn't ridiculously so and therefore may have been a worthwhile alternative investment particularly given what you get out the back side.
« Last Edit: 04/21/2018 03:45 pm by AC in NC »

Offline DistantTemple

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Re: Power options for a Mars settlement
« Reply #514 on: 04/20/2018 10:16 pm »
Yep. I read on another thread here that the larger your habitat volume, the longer it takes for the O2 mix to become seriously depleted.

And I recall also seeing that "air pockets" last far, far longer than people think. 

http://www.vocativ.com/198502/underwater-air-pocket-yangtze-river/index.html
"Hexdall calculated that, in an air pocket the size of a U-Haul moving van, it would take about 79 hours before you lost consciousness."
Yes, but its not the lack of oxygen thats the problem. Its the carbon dioxide build up that will get you in trouble first long before you run out of oxygen.
So you need first after a while CO2 scrubbing, and then later begin to need oxygen supplementation.
separate to solving these, you could have individual or room sized emergency systems based on either scrubbing or exhausting CO2 rich "air", and O2 supplementation from pressurised storage.

But for larger community and working spaces, plus for resilience, and avoiding excessive disruption from dust storms etc, you have plants, (which unfortunately need light input, which will in a dust storm be largely from likely scarce electrical power). However they should be considered a key part in maintaining breathable air.

Then there is large scale chemical scrubbing. One look at Wikipedia https://en.wikipedia.org/wiki/Carbon_dioxide_scrubber, gave several reactions the first is:
Quote from: wikipedia
The dominant application for CO2 scrubbing is for removal of CO2 from the exhaust of coal- and gas-fired power plants. Virtually the only technology being seriously evaluated involves the use of various amines, e.g. monoethanolamine. Cold solutions of these organic compounds bind CO2, but the binding is reversed at higher temperatures:

CO2  +  2 HOCH2CH2NH2  ↔  HOCH2CH2NH3+  +  HOCH2CH2NHCO2−

And since it is reversible, when the storm has passed and more energy is available the CO2 is recovered for use in Sabatier, and the monoethanolamine is recovered for use next time. This would be built into the ECLSS breathable air management system. I am no expert on this, but at first sight something like this would be an excellent and reusable buffer for periods of lacking light and energy. As for O2, just a large reserve of pressurised/liquid? O2, that is output earlier from Sabatier.

I hadn't seen this. (picture) My schoolboy chemistry guess.... at amines used for reversable CO2 capture. NASA has an experimental "Thermal Amine Scrubber" headding to the ISS on CRS-15

Although in the context of our above thread:
Quote from: wikipedia - Carbon dioxide scrubber
The dominant application for CO2 scrubbing is for removal of CO2 from the exhaust of coal- and gas-fired power plants.
Is the sort of scale needed for a large settlement.
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Online Robotbeat

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Re: Power options for a Mars settlement
« Reply #515 on: 04/20/2018 11:18 pm »
Okay, so what are the terms? No Helios scientific breakeven before end of 2019 UTC.

I consider scientific breakeven to be total input power equal to power generated by fusion. That's easier than engineering breakeven, which takes into account the efficiency of converting the heat to electricity.
I think that they have a chance to achieve scientific break even. There are a couple of caveats. It could be that Helion will only use D+D for their tests. Their Fusion Engine is supposed to extract He3 from the D+D- reaction exhaust and feed it back into the reactor as fuel for the following shot. The problem is that D+D releases less energy than D + He3 would and the extraction system might not be part of this test reactor yet. Since He3 is also very expensive, they might only do D+D shots for their experiments and then convert the resulting energy release of that into what it would have been with D+ He3, at least until they have fully optimized everything. Unlike going from D+D to D+T, going from D+D to D+He3 is actually easier, because the neutron wall loading is a lot less (among other things) and they won't need FLiBe tanks and all those complicated things that are needed for D+T burning Tokamaks. It is merely a cost saving measure if they don't do that right away.
So, I would like to include that caveat in the bet: Scientific break even with D+D result converted to D+He3 result. If you are OK with that.
Itís easier to achieve scientific breakeven with D+T, but if they truly achieve it with D+D (ie not just extrapolated based on being harder than D+T), then Iíll concede. Same with D+He3.
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Offline Elmar Moelzer

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Re: Power options for a Mars settlement
« Reply #516 on: 04/21/2018 03:52 am »
Itís easier to achieve scientific breakeven with D+T, but if they truly achieve it with D+D (ie not just extrapolated based on being harder than D+T), then Iíll concede. Same with D+He3.
[/quote]
I am not sure they will do D+He3 experiments and as I said, the output vs input of D+D is lower. So, it would be fair to let the extrapolate from the D+D results to what they would have been had they used D+He3. What really counts is the tripple product of confinement time, density and temperature. If they achieve enough of that for D+He3 fusion with a Q<1, then they have scientifically achieved break even, even if the reactor was only fueled by D+D. The rest is then a matter of replacing the fuel with He3. I am not sure it makes a lot of sense to spend the extra money for that until everything has been fully optimized, but maybe they will decide to do a few shots with He3 just to proof that they can actually do it practically and not just scientifically.
Personally, I would already be quite ecstatic if they managed to do just scientific break even. It would proof their physics and scaling laws. The rest is engineering and that will IMHO be solved quickly once the funding gates open after they have achieved that milestone.

Online Robotbeat

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Re: Power options for a Mars settlement
« Reply #517 on: 04/21/2018 05:36 am »
Then no deal. Has to be actual scientific breakeven. Dealing with the Tritium (or helium3) is part of the difficulty, and weíve been dealing with extrapolations for the last half century. (In fact, breakeven in a narrow sense has been achieved at NIF... the pellet received less energy than it produced via fusion... although that doesnít include the efficiency of the lasers or all the laser light which missed the pellet.)
« Last Edit: 04/21/2018 05:36 am by Robotbeat »
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Offline john smith 19

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Re: Power options for a Mars settlement
« Reply #518 on: 04/21/2018 06:46 am »

At this point long removed from the effort, I won't attest to the whether I did it right and was accurate in calculations.  However, I once was trying to spitball the cost of a massive solar project as a layman's perspective on what we could have alternatively done with certain large government expenses since 2000 in certain troublesome areas.

My recollection is that I validated a variety of numbers from various sources and did a back-of-the-napkin calculation that the entire US annual energy production could be replicated in a square solar-field 30 miles on a side (900 sq mi).  As I recall, this accounted for US Electrity Consumption, then-current Efficiency, reasonable assumption about Solar hours/day and weather, but perhaps not accounting for panel angle-to-the-sun and transmission losses.

The operative point I think being that it easier to do a lot with a little groundspace than you might expect.

As an aside, I think the cost of those 900 sq mi of Solar was significantly higher than the expenditures I was comparing against, but it wasn't ridiculously so and therefore may have been a worthwhile alternative investment particularly given what you get out the back side.
Just to note

That's about 1/2 million acres of land.

What happens when the sun sets?

Cut the starting sunlight by about 1/2 for Mars.
BFS. The worlds first Methane fueled FFORSC engined CFRP stainless steel structure A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP stainless steel structure booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C apply. Believe no one. Run your own numbers. So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

Offline speedevil

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Re: Power options for a Mars settlement
« Reply #519 on: 04/21/2018 08:12 am »
If you're thinking of new power sources for agriculture enabling things, think what it actually enables if freight is costing $130/kg.

In order to make it worth it growing food, you need to get under $130/day/person or so to compete with dried foods, shipped from earth).

Baseline calories from potatos can be done for $7/day. Using an utterly non-optimised solar power source. (considering only power)

Baseline oxygen at 50% conversion efficiency from the sabatier process, for free along with your fuel manufacturing efforts is $1.5 (200W average).

A 'nice' diet, with 25% of the calories from pork, and a varied vegetable /potato diet costs around $30/day.

This implies that at least the simplest power costs for food and air are not meaningful, being easily payable on a minimum wage job anywhere in 'the west'.