Author Topic: Hydrocarbon energy storage and use on the Moon  (Read 2561 times)

Offline DarkenedOne

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Re: Hydrocarbon energy storage and use on the Moon
« Reply #20 on: 10/04/2017 04:27 PM »
Nuclear power is the solution for powering a Moon base.  It is as simple as that.  All of these elaborate solutions for trying to make solar power work are really just a giant waste of time.

A nuclear reactor does not produce electricity or mechanical energy.  The heat from a nuclear reactor usually drives a turbine.  This uses a Carnot cycle.  Nuclear power works on Earth because we have lots of air and water to use as a heat sink.  On the moon you need a large panel to radiate the heat.  There is elaborate plumbing involved.  Radioisotope thermoelectric devices have less plumbing but still need a radiator panel. 

During the night you could dump the nuclear reactor's heat into the station and let the station's surface radiate.  During daylight you need to protect the station from overheating.  That could be done with some sort of screen or maybe a ... panel.

The power needs are going to be variable.  Life support (agriculture?) sets a minimum power output.  Human life support also needs redundant systems.  So around 3 weeks of unused fuel cells and batteries need to be distributed in the habitat modules.  Fuel cells can also provide drinkable water.    Rocket fuel production and metallurgy drain a lot of watts but they can wait for 2 weeks. 

A polar telescope would benefit from constant power supply.  A hot nuclear reactor would have adverse effects.  If you run a power line from the far side of a hill then you can also put solar panels on that hill.

Solar panels are handy when there is no power grid.  A rover can use them while roving for example.  If we are talking about "later" when there is a power grid then you have 24 hours of sunlight.

First of all there is a simple reason why no instrument has survived on the surface of the Moon or Mars for more than a year without nuclear power.  The thing you need most on the Moon or Mars is heat.  Human habitats especially need large amounts of heat because unlike the electronics in the rovers, which can easily endure freezing temperatures, our core body temperature needs to be remain 98 degrees.  On the moon each night is 13 days long.
 On Mars the nights are about as long as they are on Earth, but the winters are twice as long.  In fact I would be willing to bet you that a permanent habitat on the Moon will likely need more heat energy than electrical energy.  On top of that many of the things you want to do like produce rocket fuel involve endothermic chemical reactions that require heat.  Nuclear cogeneration systems are ideal because they can provide both heat and electricity. 

Secondly have you ever done any calculations to determine what you would need to have "3 weeks" of power in batteries or fuel cells.  You are talking about a ridiculous amount of mass.
« Last Edit: 10/04/2017 04:32 PM by DarkenedOne »

Offline matterbeam

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Re: Hydrocarbon energy storage and use on the Moon
« Reply #21 on: 10/04/2017 04:55 PM »
First of all there is a simple reason why no instrument has survived on the surface of the Moon or Mars for more than a year without nuclear power.  The thing you need most on the Moon or Mars is heat.  Human habitats especially need large amounts of heat because unlike the electronics in the rovers, which can easily endure freezing temperatures, our core body temperature needs to be remain 98 degrees.  On the moon each night is 13 days long.
 On Mars the nights are about as long as they are on Earth, but the winters are twice as long.  In fact I would be willing to bet you that a permanent habitat on the Moon will likely need more heat energy than electrical energy.  On top of that many of the things you want to do like produce rocket fuel involve endothermic chemical reactions that require heat.  Nuclear cogeneration systems are ideal because they can provide both heat and electricity. 

Secondly have you ever done any calculations to determine what you would need to have "3 weeks" of power in batteries or fuel cells.  You are talking about a ridiculous amount of mass.

Energy, or mass. Thickly insulated habitats can drastically reduce the heat leaking out of human-occupied spaces. They will mass a lot, but potentially less than an electrical power supply and heating system to compensate for the heat loss. If the insulation is made out of local materials, then it is the best option.

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Offline hop

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Re: Hydrocarbon energy storage and use on the Moon
« Reply #22 on: 10/04/2017 09:14 PM »
First of all there is a simple reason why no instrument has survived on the surface of the Moon or Mars for more than a year without nuclear power.
Opportunity has been operating on Mars for over 13 years. Admittedly, it does use RHUs for heating some components, but all electrical power comes from solar. The Yutu rover and lander were also solar powered (reportedly with RHUs on the rover at least, but to what extent is unclear). AFAIK, the lander is still operating.

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The thing you need most on the Moon or Mars is heat.
Things like exposed actuators tend to need significant heating, but this is not necessarily true for habitats. You don't have to go very far underground to get a pretty steady temperature. Equipment and humans generate significant waste heat, and vacuum + MLI is a very good insulator.

Offline matterbeam

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Re: Hydrocarbon energy storage and use on the Moon
« Reply #23 on: 10/04/2017 09:24 PM »
@hop
Are you the author of Hop's Blog? http://hopsblog-hop.blogspot.co.uk/
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Offline hop

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Re: Hydrocarbon energy storage and use on the Moon
« Reply #24 on: 10/04/2017 09:30 PM »
Are you the author of Hop's Blog? http://hopsblog-hop.blogspot.co.uk/
Nope. I believe the author is Hop_David on this forum.

Offline DarkenedOne

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Re: Hydrocarbon energy storage and use on the Moon
« Reply #25 on: 10/05/2017 04:14 AM »
First of all there is a simple reason why no instrument has survived on the surface of the Moon or Mars for more than a year without nuclear power.
Opportunity has been operating on Mars for over 13 years. Admittedly, it does use RHUs for heating some components, but all electrical power comes from solar. The Yutu rover and lander were also solar powered (reportedly with RHUs on the rover at least, but to what extent is unclear). AFAIK, the lander is still operating.

Exactly like I said.  Those missions would be practically impossible without the RHUs.  There are weeks where the Mars rovers would not collect enough power to do anything, but the RHUs kept them warm enough to survive.
 With solar power and batteries you simply are not able to generate and store enough energy to keep the rovers warm at nights and during the winter.  With humans it becomes a much bigger issue.  You need much more heat.  You also need a very constant and reliable amount of power. 

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The thing you need most on the Moon or Mars is heat.
Things like exposed actuators tend to need significant heating, but this is not necessarily true for habitats. You don't have to go very far underground to get a pretty steady temperature. Equipment and humans generate significant waste heat, and vacuum + MLI is a very good insulator.

Sure but the first outposts will not be underground.

Offline hop

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Re: Hydrocarbon energy storage and use on the Moon
« Reply #26 on: 10/05/2017 06:36 AM »
Exactly like I said.  Those missions would be practically impossible without the RHUs.
Not really. Each MER used 8 RHUs, with ~1 W thermal output per RHU (https://solarsystem.nasa.gov/rps/rhu.cfm). An extra ~200 Wh/day would certainly be annoying to supply with solar, but you could do a pure solar MER if you really had to.
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Sure but the first outposts will not be underground.
No, but they will be in vacuum.

There's certainly arguments to be made for nuclear reactors, but keeping the habitat warm doesn't seem like a particularly compelling one to me.

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