Author Topic: Power options for a Mars settlement  (Read 75302 times)

Offline CuddlyRocket

Re: Power options for a Mars settlement
« Reply #420 on: 06/18/2017 02:55 PM »
Just use CO/O2 as a fuel system. Then you don't need to mine water and don't need to collect the exhaust.
In principle this is a backup system that is only needed in emergencies. On that basis any system should leverage as much existing infrastructure as possible. Since SX have decided on Methalox (and show no signs of changing that decision) the simplest option is to run power generation (either combustion based or FC) with the same reactants, running overnight needs on batteries.

I agree with using methalox for emergency power supplies if methalox is available - i.e. you happen to be near where methalox propellant production facilities are sited, which will be true in the early days. But any settlement is likely to soon have outposts and a CO/O2 system might then be useful as an emergency backup power system; perhaps even a non-emergency one. The obvious alternative is simply more batteries, but batteries are heavy, expensive and need a great deal of industrial infrastructure to manufacture. A CO/O2 system may be more easily manufactured on Mars. I foresee an engineering trades analysis!

Offline guckyfan

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Re: Power options for a Mars settlement
« Reply #421 on: 06/18/2017 03:54 PM »
A system that can burn both CO/O2 and methane O2 would be helpful at the main site. CO/O2 can keep heavy industry running over night and may be more efficient than batteries, when weight and lifespan is included. In emergencies like long dust storms the propellant store can be used.

Offline CuddlyRocket

Re: Power options for a Mars settlement
« Reply #422 on: 06/20/2017 04:58 AM »
A system that can burn both CO/O2 and methane O2 would be helpful at the main site. CO/O2 can keep heavy industry running over night and may be more efficient than batteries, when weight and lifespan is included. In emergencies like long dust storms the propellant store can be used.

Good idea. Dual fuel shouldn't be a problem (the on-board generator for the Wrightspeed hybrid truck is a micro-turbine that is designed to run on diesel, compressed natural gas, liquid natural gas, liquid propane, or landfill gasses).

You might want generators at two sites (and away from any batteries) for redundancy/safety reasons. Just as you probably don't want to keep all your propellant in two big tanks. Though such redundancy comes at a cost, of course.

Offline john smith 19

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Re: Power options for a Mars settlement
« Reply #423 on: 06/21/2017 10:53 AM »
Good idea. Dual fuel shouldn't be a problem (the on-board generator for the Wrightspeed hybrid truck is a micro-turbine that is designed to run on diesel, compressed natural gas, liquid natural gas, liquid propane, or landfill gasses).
I had not heard of Wrightspeed before. There technology sounds interesting and the power level seems to be in the range that a small settlement would need, although you could cluster them for larger sizes. 
Quote from: CuddlyRocket
You might want generators at two sites (and away from any batteries) for redundancy/safety reasons. Just as you probably don't want to keep all your propellant in two big tanks. Though such redundancy comes at a cost, of course.
The last thing you want is your contingency system (which is only operating in an emergency) to fail on you, making what's already a serious situation worse.

If the system could run on either CO or CH4 you would have two sets of tanks anyway. Keep in mind while on emergency power it's likely all propellant production will be shut down and if the system has to switch to Methalox burning things will have gotten very serious.
BFS. The worlds first Methane fueled FFORSC engined CFRP structured A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP structured booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C Apply So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

Offline Ludus

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Re: Power options for a Mars settlement
« Reply #424 on: 06/27/2017 04:37 PM »
From the POV of a commercial project, Solar Power Satellites in Areostationary Orbit have some real advantages. ASO is less than half the distance of GSO, not much atmosphere to get in the way, no real environmental issues or land issues with the rectenna.

SPS's have the advantage of scaling. If you have a design that can deploy itself and start beaming power it can be replicated and improved. Local conditions don't change for every deployment.

The system is likely to be lower upkeep. Ground PV has to be kept free of dust. Rectennas are likely much less trouble.

It provides reliable power 24/7 unlike ground Solar, without batteries. Unlike the Terrestrial version it's not competing with Solar PV with zero launch cost...it all has to get to Mars one way or another.

It's flexible. If Mars has a new settlement it can be powered right away hundreds of miles from old settlements.

It's a utility service that bills for power delivered not a product.

Mars will need a lot of electricity.

Offline jpo234

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« Last Edit: 03/09/2018 07:24 PM by jpo234 »
You want to be inspired by things. You want to wake up in the morning and think the future is going to be great. That's what being a spacefaring civilization is all about. It's about believing in the future and believing the future will be better than the past. And I can't think of anything more exciting than being out there among the stars.

Offline Hominans Kosmos

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Re: Power options for a Mars settlement
« Reply #426 on: 03/09/2018 10:29 PM »
MIT Aims To Bring Nuclear Fusion To The Market In 10 Years

http://www.wbur.org/bostonomix/2018/03/09/mit-nuclear-fusion

https://www.engadget.com/2018/03/09/mit-embarks-ambitious-plan-build-nuclear-fusion-2033/

For some context and background on those articles





TL;DR: commercial availability of continuously improving magnetic field and current density compatible high temperature superconductors. 
Basically the remaining job is commercializing the specific integration of the commercial off-the-shelf technologies in modern start-up fashion, quickly and efficiently.

It seems reasonable to expect these aspirations to be met. This would make these commercial reactor technologies available for the aerospace community to lightweight for airlift and space-lift compatible versions.

Edit: disambiguating field strength and current density
« Last Edit: 03/09/2018 11:21 PM by Hominans Kosmos »

Offline speedevil

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Re: Power options for a Mars settlement
« Reply #427 on: 03/09/2018 10:50 PM »
TL;DR: commercial availability of continuously improving magnetic field density resistant high temperature superconductors. 
Basically the remaining job is commercializing the specific integration of the commercial off-the-shelf technologies in modern start-up fashion, quickly and efficiently.

It seems reasonable to expect these aspirations to be met. This would make these commercial reactor technologies available for the aerospace community to lightweight for airlift and space-lift compatible versions.

I just watched that a few days ago.
There are major caveats in lightweighting - namely that as I understand it, other than for the ancillary systems, you pretty much can't, this is the minimal size.

The whole thing pretty much needs to be largely steel, or coolant, or superconductor wire, and you can't go significantly under 6m diameter, or the scaling goes all wrong.

However.
This isn't too disasterous, the weight of the system is not >20000 tons for the reactor like ITER, but more like 300-400 tons.

But, it gets better!
Due to the design, you can obviously drain the coolant, and remove the vacuum vessel and inner superconductors (it's designed for this for servicing), and get it in two major halves of about 150 tons each.
A number you may remember from elsewhere.

You then need probably several more loads of cryogenics, heat radiators, generators, and such. But then if you get it working, your only meaningful import for power per 500MW-years becomes the vacuum vessel and superconductors, which are a consumable, weighing perhaps 50 tons.

(assuming it works according to the design shown)

Offline redskyforge

Re: Power options for a Mars settlement
« Reply #428 on: 04/10/2018 01:48 PM »
One point I've not seen discussed very much is how much baseload vs dispatchable power will be needed on Mars.

Given by far the greatest power requirement comes from the Sabatier plant making rocket fuel, I think the answer to this hinges on how amenable our hypothetical Mars-based Sabatier plant will be to shutting down and starting up again. I know that in heavy industry on Earth some industries are very suitable to Demand Side Response, is this the case with the Sabatier plant? What kind of penalties are there to shutting down/starting up? What losses are there, and how agile (fast) can a shutdown/startup be done in this kind of process?

Offline CuddlyRocket

Re: Power options for a Mars settlement
« Reply #429 on: 04/11/2018 06:06 PM »
One point I've not seen discussed very much is how much baseload vs dispatchable power will be needed on Mars.

Given by far the greatest power requirement comes from the Sabatier plant making rocket fuel, I think the answer to this hinges on how amenable our hypothetical Mars-based Sabatier plant will be to shutting down and starting up again. I know that in heavy industry on Earth some industries are very suitable to Demand Side Response, is this the case with the Sabatier plant? What kind of penalties are there to shutting down/starting up? What losses are there, and how agile (fast) can a shutdown/startup be done in this kind of process?

I don't know the answer to that, but the ability to reduce power consumption significantly would be desirable, especially if solar was a significant source of electrical power - at night and during dust storms, for example. But you might not need to shut down the propellant plant; reducing output may be sufficient.

Minimum baseload is presumably life-support and keeping essential equipment etc running.

Offline envy887

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Re: Power options for a Mars settlement
« Reply #430 on: 04/11/2018 07:12 PM »
One point I've not seen discussed very much is how much baseload vs dispatchable power will be needed on Mars.

Given by far the greatest power requirement comes from the Sabatier plant making rocket fuel, I think the answer to this hinges on how amenable our hypothetical Mars-based Sabatier plant will be to shutting down and starting up again. I know that in heavy industry on Earth some industries are very suitable to Demand Side Response, is this the case with the Sabatier plant? What kind of penalties are there to shutting down/starting up? What losses are there, and how agile (fast) can a shutdown/startup be done in this kind of process?

I don't know the answer to that, but the ability to reduce power consumption significantly would be desirable, especially if solar was a significant source of electrical power - at night and during dust storms, for example. But you might not need to shut down the propellant plant; reducing output may be sufficient.

Minimum baseload is presumably life-support and keeping essential equipment etc running.

Not all life support has to be baseload. You could use consumable stores (e.g. O2, water) when you don't have power, then regenerate (by electrolysis, filtration, etc.) them when you do.

Offline jpo234

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Re: Power options for a Mars settlement
« Reply #431 on: 04/11/2018 07:21 PM »
One point I've not seen discussed very much is how much baseload vs dispatchable power will be needed on Mars.

Given by far the greatest power requirement comes from the Sabatier plant making rocket fuel, I think the answer to this hinges on how amenable our hypothetical Mars-based Sabatier plant will be to shutting down and starting up again. I know that in heavy industry on Earth some industries are very suitable to Demand Side Response, is this the case with the Sabatier plant? What kind of penalties are there to shutting down/starting up? What losses are there, and how agile (fast) can a shutdown/startup be done in this kind of process?
The assumption was, that the generated fuel would also serve as electricity source while solar power is not available.

This obviously does not work to power the ISRU plant...
« Last Edit: 04/11/2018 07:22 PM by jpo234 »
You want to be inspired by things. You want to wake up in the morning and think the future is going to be great. That's what being a spacefaring civilization is all about. It's about believing in the future and believing the future will be better than the past. And I can't think of anything more exciting than being out there among the stars.

Offline redskyforge

Re: Power options for a Mars settlement
« Reply #432 on: 04/11/2018 07:22 PM »
One point I've not seen discussed very much is how much baseload vs dispatchable power will be needed on Mars.

Given by far the greatest power requirement comes from the Sabatier plant making rocket fuel, I think the answer to this hinges on how amenable our hypothetical Mars-based Sabatier plant will be to shutting down and starting up again. I know that in heavy industry on Earth some industries are very suitable to Demand Side Response, is this the case with the Sabatier plant? What kind of penalties are there to shutting down/starting up? What losses are there, and how agile (fast) can a shutdown/startup be done in this kind of process?

I don't know the answer to that, but the ability to reduce power consumption significantly would be desirable, especially if solar was a significant source of electrical power - at night and during dust storms, for example. But you might not need to shut down the propellant plant; reducing output may be sufficient.

Minimum baseload is presumably life-support and keeping essential equipment etc running.

Not all life support has to be baseload. You could use consumable stores (e.g. O2, water) when you don't have power, then regenerate (by electrolysis, filtration, etc.) them when you do.

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. It sounds like given the 'planned economy' of a Martian colony, very little baseload is necessary - night times and local dust storms could almost certainly be powered by a relatively modest battery backup (we're seeing more and more utility-scale battery deployments on Earth. They'll only get cheaper and better). However, surviving longer dust storms remains a challenge. I think it would be crazy not to have some kind of backup Methane turbine/generator for these situations, given the stockpiles the colony will have for most of the synod.

Does anyone know how flexible a Sabatier plant can be?
« Last Edit: 04/11/2018 07:25 PM by redskyforge »

Offline AC in NC

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Re: Power options for a Mars settlement
« Reply #433 on: 04/11/2018 09:18 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."

Offline Steve D

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Re: Power options for a Mars settlement
« Reply #434 on: 04/11/2018 09:45 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.

Offline whitelancer64

Re: Power options for a Mars settlement
« Reply #435 on: 04/11/2018 09:57 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.

That's exactly what that article says.
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Online DistantTemple

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Re: Power options for a Mars settlement
« Reply #436 on: 04/11/2018 10:09 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.
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Offline AC in NC

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Re: Power options for a Mars settlement
« Reply #437 on: 04/11/2018 10:39 PM »
And I recall also seeing that "air pockets" last far, far longer than people think. 

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.

That's exactly what that article says.

And a perfect example of the point in bold red above.   ;D
« Last Edit: 04/11/2018 10:40 PM by AC in NC »

Online Robotbeat

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Re: Power options for a Mars settlement
« Reply #438 on: 04/12/2018 01:11 AM »
BTW, if you have access to vacuum, then CO2 scrubbing is pretty easy with some valves. The only problem is Mars isn't totally a vacuum as it has a CO2 partial pressure higher than usual Earth air. But regardless, even if you need a more active scrubber, it doesn't take much energy compared to oxygen production.
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Offline spacenut

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Re: Power options for a Mars settlement
« Reply #439 on: 04/12/2018 04:12 AM »
I like the idea of polar orbital solar power at the dusk-dawn area of around Mars.  The solar power would always be facing the sun while beaming the power to a dark side receiving antenna for night power.  Having several solar stations orbiting Mars in this vertical orbital plane could actually beam power almost anywhere on Mars at any time.  Not as much need for batteries. 

Another idea is to split water during the day into hydrogen and oxygen, then use the two as batteries at night like they did with Apollo and have water reproduced as a by product.  All this in a closed system. 

Small scale fission reactors will probably eventually be brought, coupled together to produce all the power they need for industrial scale uses.