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#601 2021-11-04 14:29:13

kbd512
Administrator
Registered: 2015-01-02
Posts: 5,842

Re: Going Solar...the best solution for Mars.

SpaceNut,

The US had its first armed combat drones in 1944, but they were never used in combat.  We had experimented with RC drone aircraft for at least a decade at that point.  I think some of our first experiments with remotely piloted aircraft were not long after WWI, meaning 1920s.  The Naval Aircraft Factory TDN-1 RPV was an optionally piloted twin-engine drone aircraft equipped with a single 2,000 pound iron bomb or Mk 13 torpedo.  4 prototypes and 100 operational examples were built during the war.  As previously stated, tested in mock combat, but never used in actual combat.  These aircraft were of wooden construction, had fixed tricycle landing gear, operated from carrier flight decks like normal carrier aircraft, and contained a television camera or radar system with the signal relayed back to a remote viewing station aboard a TBM Avenger aircraft located up to 8 miles away.  Experiments were also conducted with a single airborne operator controlling multiple drones at the same time.

We had fully autonomous radar-guided glide bombs (the ASM-N-2 Bat was used operationally in the Pacific theater of war) that successfully sank or heavily damaged a number of Japanese ships in the Pacific.  These guided weapons were equipped with 1,000 pound warheads from regular iron bombs.  They were constructed of plywood, used Lead-acid car batteries to power the radar and flight control servos, were fire-and-forget weapons rather than radio-controlled / remotely-piloted, the airframe and electronics weighed 600 pounds, the weapons attained glide speeds of 140 to 210 knots, and a few dozen or so were used in successful attacks at ranges of up to 20 nautical miles when dropped from 25,000 feet.  The length was just shy of 12 feet and the wingspan was 10 feet.  The Bats entered into service in 1945 and were carried into combat by Corsair fighters, Catalina flying boats, and Privateer heavy bombers.  2,580 of these Bat glide bombs were built.

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#602 2021-11-04 17:11:43

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: Going Solar...the best solution for Mars.

I was amazed to read a few years ago that the Russians had (small) "robot" tanks, rado guided I think,  that they used in WW2.

kbd512 wrote:

SpaceNut,

The US had its first armed combat drones in 1944, but they were never used in combat.  We had experimented with RC drone aircraft for at least a decade at that point.  I think some of our first experiments with remotely piloted aircraft were not long after WWI, meaning 1920s.  The Naval Aircraft Factory TDN-1 RPV was an optionally piloted twin-engine drone aircraft equipped with a single 2,000 pound iron bomb or Mk 13 torpedo.  4 prototypes and 100 operational examples were built during the war.  As previously stated, tested in mock combat, but never used in actual combat.  These aircraft were of wooden construction, had fixed tricycle landing gear, operated from carrier flight decks like normal carrier aircraft, and contained a television camera or radar system with the signal relayed back to a remote viewing station aboard a TBM Avenger aircraft located up to 8 miles away.  Experiments were also conducted with a single airborne operator controlling multiple drones at the same time.

We had fully autonomous radar-guided glide bombs (the ASM-N-2 Bat was used operationally in the Pacific theater of war) that successfully sank or heavily damaged a number of Japanese ships in the Pacific.  These guided weapons were equipped with 1,000 pound warheads from regular iron bombs.  They were constructed of plywood, used Lead-acid car batteries to power the radar and flight control servos, were fire-and-forget weapons rather than radio-controlled / remotely-piloted, the airframe and electronics weighed 600 pounds, the weapons attained glide speeds of 140 to 210 knots, and a few dozen or so were used in successful attacks at ranges of up to 20 nautical miles when dropped from 25,000 feet.  The length was just shy of 12 feet and the wingspan was 10 feet.  The Bats entered into service in 1945 and were carried into combat by Corsair fighters, Catalina flying boats, and Privateer heavy bombers.  2,580 of these Bat glide bombs were built.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#603 2021-11-04 20:35:02

kbd512
Administrator
Registered: 2015-01-02
Posts: 5,842

Re: Going Solar...the best solution for Mars.

Louis,

I went back and checked.  The US started initial drone aircraft experiments much earlier than I recalled, around 1910.

The Russian Teletank was a very impressive radio controlled machine, able to execute up to 24 different commands.  They were much further along than any other nation in the realm of unmanned ground vehicles.

The Germans had much smaller wire-controlled tracked bombs, nicknamed Goliath.  The first variant was battery powered.  It was pretty useless, so they replaced the batteries and electric motors with a small 2-cylinder combustion engine, increasing its operational range by 10 times over the battery powered vehicle while also permitting the explosive charge it carried to be increased from 60kg to 100kg.

The US experimented with RC vehicles for decades before WWII, but never fielded any remote vehicles until long after the war.  The Luftwaffe dispatched both crewed and radio-controlled Russian tanks with reckless abandon, so that was probably for the best.  Still, it would've been nice to have a remote-controlled lead tank since those tended to be the first to get hit when ambushed by anti-tank guns or other tanks.

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#604 2021-11-19 15:05:09

tahanson43206
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Registered: 2018-04-27
Posts: 10,760

Re: Going Solar...the best solution for Mars.

https://currently.att.yahoo.com/finance … 00939.html

The so-called Antípodas project will be based on the enormous solar energy potential of Chile’s Atacama Desert, the driest non-polar desert in the world. While temperatures in the Atacama are usually relatively temperate, they can soar to 130 degrees Fahrenheit (50 degrees Celsius). The almost entirely cloudless desert is the region in the world with the highest rates of solar radiation, making it a prime location for a solar farm.

Getting all that solar energy to Chinese markets, however, may be tricky. On top of the hefty price tag of the cable itself, China will have to seriously invest in building out its solar plant infrastructure in order to make way for Chile’s prodigious 3,106 MW of already-installed photovoltaic capacity. It will also require a lot of geopolitical dealmaking between Chile, China, and other Asian economies.

For Louis !!!

(th)

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#605 2021-11-19 15:36:23

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 25,943

Re: Going Solar...the best solution for Mars.

A really long power cable for sure....and longer going to mars....

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#606 2021-12-03 20:22:44

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 25,943

Re: Going Solar...the best solution for Mars.

I will move this if I am in the wrong topic

https://mars.nasa.gov/files/resources/M … _Final.pdf

Power for orbiter:
More than 2,000 solar cells on four panels, covering 129 square feet (12 m 2) .
Solar panels generate between 1,150 and 1,700 watts . Wattage depends on the spacecraft’s position in Mars orbit .
The panels power two 55-amp-hour Lithium ion batteries

Orbit is elliptical; distance from sun varies from a minimum of 128 .4 million miles (206 .7 million km) to a maximum of 154 .8 million miles (249 .2 million km); average is 141 .5 million miles (227 .7 million km)

Revolves around sun once every 687 Earth days
Rotation period (length of day): 24 hours, 39 minutes, 35 seconds (1 .03 Earth days)
Poles tilted 25 degrees, creating seasons similar to Earth’s

Average diameter 4,212 miles (6,780 km)
Lowest orbital altitude: 77 .6 miles (125 km) above Mars surface, within the upper atmosphere
Highest orbital altitude: 3,864 miles (6,220 km) above Mars surface

This will support a mars solar ring structure to beam energy or to be made of for the atmospheric drop to create a balloon platform ring around mars.

https://ntrs.nasa.gov/api/citations/199 … 010257.pdf
Solar Radiation on Mars: Stationary .... Photovoltaic Array

https://ntrs.nasa.gov/api/citations/200 … 191326.pdf
Mars Solar Power for the mars polar lander mission support

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#607 2021-12-12 13:18:38

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 25,943

Re: Going Solar...the best solution for Mars.

This is a diy home build but its the information that we can make use of.

https://youtu.be/vng-CACPow0
Our Complete Solar System Cost With Battery Backup! 10kw Of Power

https://www.signaturesolar.com/?ref=cou … experience
all of our solar components at Signature Solar

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#608 2021-12-12 19:05:39

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 3,206

Re: Going Solar...the best solution for Mars.

SpaceNut wrote:

yes a battery can be a ripple current feature that means you are doing direct near full conversion to use with little being saved into long term storage.

This is a large thread and I'm still getting through it and I don't know if this was already discussed on this thread but has anyone looked at beaming energy Space Solar Power by microwave or laser and through Satellites into the Colder regions on Mars and use Satellites to beam and transport energy as a Possibility?

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#609 2021-12-12 19:12:42

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 1,955

Re: Going Solar...the best solution for Mars.

Mars_B4_Moon wrote:
SpaceNut wrote:

yes a battery can be a ripple current feature that means you are doing direct near full conversion to use with little being saved into long term storage.

This is a large thread and I'm still getting through it and I don't know if this was already discussed on this thread but has anyone looked at beaming energy Space Solar Power by microwave or laser and through Satellites into the Colder regions on Mars and use Satellites to beam and transport energy as a Possibility?

It has been discussed and is a good idea.  If we are relying on imported solar power infrastructure, then beyond a certain power output it may make sense leaving the panels in Mars orbit and beaming the power to ground.  That critical size will be in GW power range.


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#610 2021-12-29 11:43:30

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 25,943

Re: Going Solar...the best solution for Mars.

I continually look for what is being sold as kits for being able to deploy solar at a reasonable cost for home use and I keep finding specifications that are getting blurred and the actual performance is not really what is being advertised.

I was looking for a sine wave battery inverter for use for creating line voltage but some of these state Expertpower 2.5KWH 12V Solar Power Kit | Lifepo4 12V 100Ah, 400W Mono Solar Panels, 30A MPPT Solar Charge Controller, 3KW Pure Sine Wave Inverter

First clue is they try to give you the kwhr ratings and since this is solar means they are trying to calculate best alignment and max hours to store. Of course that is in a 12v at 100Ahr = 1,200 whr so we must have more than 1 battery to achieve the storage. It says that the inverter is 3kw and that means the Ahr and battery count are off..

It is soldon Amazon with same tag line

This Off-Grid Solar System Kit includes two 12V100Ah LiFePO4 batteries, 4 x 100W Monocrystalline Solar Panels

2.5kwhr means we are to get the panels to receive 6.25 hrs of direct sunlight to achieve that rating, which means that is not happening.

The 2 batteries in parallel means we have a working wattage of 2,400 watts for an hour of power we can draw from with the kit having the 200 Ahr battery option which would double that for 4,800 watts for an hour to start with for usage which is closer to the inverter rating. Of course when we use power we are not paying attention to any of these values so one 1500w appliance would get just 2 hours of use from the device.

That make is plausible for Th use with batteries fully charged and not hauling the panels around but we would need many of these for a human use.

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#611 2022-01-09 17:24:23

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 25,943

Re: Going Solar...the best solution for Mars.

kbd512 wrote:

tahanson43206,

Mars is so energy-poor that any significant settlement will require nuclear power.  No amount of "green ideology" will affect the fact that anyone living on Mars, energy-wise, is between a proverbial "rock and a hard place".  The energy usage at our Antarctic research station is sky-high, yet they produce no food for themselves, no atmospheric breathing gases are produced or recycled, no construction takes place on-site except using diesel powered machinery, and they do very little in the way of waste water recycling (they treat grey water and then they discharge it, because they're literally sitting on a functionally limitless supply of fresh water).  To support those very limited scientific research activities in the Antarctic, they burn an incredibly amount of diesel fuel each day.  The researchers do get supplemental power from wind, solar, and batteries.  Antarctica is rich in wind, but relatively poor in solar.  There's no usable wind power or hydro power on Mars, which leaves solar and batteries as the sole alternative, which also happens to be the least energy-dense form of fuels that humanity has learned how to use.

We supply 300,000 liters / 79,250 gallons of diesel fuel per year, in order to support 10 (winter) to 80 (summer) people.  Each gallon of diesel fuel represents 40,700Wh of thermal power, or 3,225,475,000 / 3.2GWh of power for 10 to 80 people over 1 year.  Each kilo of U235 is 24GWh per kg, if fully consumed in a nuclear reactor.  To supply daily power, batteries would have to store 8,836,918Wh, and to have any kind of reasonable battery life, that has to be doubled to 17,673,836Wh.  That equates to 70,695kg of batteries, which is either at or over the shipping weight of 10MWe class truck-transportable nuclear reactor cores.  If we're lucky, those batteries might last for 10 years (3,650 charge / discharge cycles) before replacement is required.

Mars InSight lander has an active array area of 5.14m^2 and generated approximately 4,600Wh on Day 1 (IIRC, actual output was 4,585Wh or thereabouts).  That equates to 895Wh/m^2 of "Day 1" / "perfectly clean" output.  Total array output dropped like a rock to, IIRC, a mere 700Wh in less than 2 years, due to accumulation of atmospheric dust.  Therefore, solar arrays DO have to be kept clean on a routine basis to prevent dramatic loss of power output.  We will assume that we can clean the arrays, though, because we do that in the deserts here on Earth, where it is equally necessary to maintain output.

That info comes from this document.  This is a comprehensive analysis of measured versus estimated output using state-of-the-art photovoltaic array equipment optimized for LILT (Low-Intensity / Low-Temperature) conditions:

Scientific Observations With the InSight Solar Arrays: Dust, Clouds, and Eclipses on Mars

Maximum Wh/m^2 is therefore around 900Wh/m^2 on Mars, under ideal conditions using 35% efficient triple-junction Silicon wafer-based photovoltaics with a very thin but very hard cover-glass that prevents the crazing problem that both Robert Dyck and myself have stated is a real issue with soft plastics.  Therefore, an absolute bare minimum of 9,819m^2 of array area (99m by 99m; a professional soccer field is 7,140m^2 and a NFL football field is 5,351m^2, for comparison purposes), at 900Wh/m^2, is required to supply power before any losses are taken into account.  Recall that here in Texas 23% of the electrical power is lost in the wiring and PMAD (Power Management And Distribution) equipment before the power touches the main line that feeds it into the grid.  Using my proposed 2kg/m^2 advanced CFRP / Kevlar honeycomb backer board with the same wafer-based photovoltaic panel design with 0.5kg allocated to a CFRP or CNT support structure (vastly lighter than anything used commercially here on Earth and lighter than ISS arrays), we're looking at 24,548kg for the panels without any wiring or PMAD equipment.

I don't know what voltages would be used, but if we use a small town photovoltaic array as our facsimile, then I estimate another 5,000kg for wiring / PMAD / circuit breakers using lightweight equipment, assuming Aluminum wiring is used.  CNT is likely required to achieve that mass target.  We can only be so smart about how we wire the panels to minimize wiring runs, and the more amps of power we provide, the thicker the gauge of wiring required.  Looking at lower output Earth-bound arrays, we'll see that 5,000kg is much nearer to a pipe dream than a practical tonnage figure.  In all probability, the wiring and PMAD mass will be a significant fraction of the array mass than my optimistic estimate, but let's be "dreamers" here.

That's around 100t to supply power for 10 people in Antarctica or on Mars, where the life support power requirements are much much higher.  The batteries, which represent 70% of the equipment mass, will not last more than 10 years before replacement is required.  If we assert that that amount of power could also keep 10 people alive on Mars (even though it cannot if food must be grown, CO2 scrubbed, and water ice melted for consumption).  That equates to 10,000,000,000kg / 10,000,000t for a 1,000,000 person Mars colony.  Total mass of all objects sent into space is 9,800t, but we'll call it 10,000t for easy math.  This 1,000,000 person Mars colony therefore requires 1,000X as much mass, not to Earth orbit but to Mars- "JUST" TO PROVIDE BASIC LIFE SUPPORT POWER, NO FOOD OR ISRU, IF WE INSIST ON USING PHOTOVOLTAICS AND BATTERIES!  Anyone who thinks that's practical to do is living in their own personal fantasy land.  That's 100,000 launches at 100t per launch, except we need 6 to 8 launches to deliver that tonnage to Mars, which means 700,000 launches.  At a mere $2M USD per Starship launch, that's $200B per 100,000 launches, or $1.4T USD for 700,000 launches.  You have to wonder about their inability to do basic math and accept.  We have to replace 70% of that mass every 10 years and 90% to 100% every 25 years, until 100% of the colony's power requirements are met by local production.  If it takes 25 years to grow the colony to 1,000,000 colonists, how practical does that seem to you?

We could obviously set up a photovoltaic or battery manufacturing plant on Mars using ISRU, but what would that require?

More equipment mass, more input power, more people to work in the factory, which in turn requires more mass and power...  It's a vicious cycle.

It's a fool's errand.  It's a fantasy-based proposal from people who refuse to accept basic math, because the results of the equations are so devastating to their ideologically-motivated beliefs.  Similarly, my admonishment to use simpler but more reliable and longer-lived heat engines, despite having a lower overall efficiency, is all about basic math.  Anyone who asserts that math doesn't matter does not believe in science, they believe in their own form of religion.  Those who know me also know that I am not a fan of any kind of religion, and have a particular mistrust of organized religion.  This is the reason why- the solutions they come up with are seldom, if ever, practical solutions that can be applied to a real world engineering problem.

Recall that at least several times I've stated that fission power alone is not enough, and that we probably need fusion power, in addition to the fission and solar thermal heat engines to generate the staggering amount of power required.  Power production is and always has been the name of the game.  You need mass and energy devoted to every other aspect of life apart from merely generating or storing enough power.  The use of low energy density batteries drastically adds to the total mass of the solution.  The greater the tonnage of power generating or storage equipment you have to ship, the less tonnage devoted to every other aspect of living on Mars.  I go over this aspect of living on Mars again and again and again, because it dictates how fast the colony can grow and how many people it can realistically support at any given time.  There are no other "natural resources" that can be used without the master resource- ENERGY!

It's not my fault that existing energy generation and storage technology does what it does, and can do no more.  That's the entire reason we continue to pursue fusion power.  Every big "jump up" the "order of magnitude scale" that you make, with respect to energy output, the greater the technological capabilities of your civilization.  None of it is truly "clean", none of it is truly "renewable", it's just a question of trade-offs and what you want to devote energy output to- "making more energy" with diffuse / intermittent power sources, or "all other human activities" with reliable and continuous generation with minimal "natural resource" consumption.  The more you understand of the basic math involved, the less prone you are to having someone sell you a bill of goods that does not meet or even approach the terms of the sales pitch.

If it was up to me, we'd be using hydro / geothermal / solar and nuclear thermal engines to power human civilization while devoting all available brain power and funding to fusion power.  Whereupon we have pervasive deployment of practical fusion reactors, then we can supply the electrical power to attempt to electrify nearly every aspect of human life- from transportation to home heating.  We also have excess power to tinker endlessly with photovoltaics and batteries (satisfy the curiosity or religious beliefs of scientists and environmentalists), with virtually no threat to the continued existence of a technologically advanced human civilization capable of space flight and colonization.  Unfortunately, politics and ideology have been unrecognizably contorted to promote a self-destructive anti-humanist ideology of scarcity and austerity, which have historically been abject failures every single time they're attempted, much like communism.  I like the arts and artists, so to preclude energy poverty from forcing those people to instead become farmers or mechanics or pursue any other career path for which they are manifestly unsuited, humanity requires abundant power / food / clothing / shelter / medical care (all the "good stuff" that comes from energy abundance).  Abundance only continues while the machinery of human civilization is kept well-oiled and humming along at full output.

Anyway, at this point I've restated this in as many different ways as I know how.  Some people will "get it", while others will not.  I have nothing against using any form of power, but its limitations should be well known unto its users and respected as such.

Another why we will use solar once we establish a real power source as nuclear

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#612 2022-01-15 18:57:07

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 25,943

Re: Going Solar...the best solution for Mars.

Recycling solar panels to help climate crisis

Ph.D. student, Natalie Click, shares how solar panels can be recycled to cut costs and help fight against climate change.

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#613 2022-01-29 11:41:25

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 25,943

Re: Going Solar...the best solution for Mars.

All the array hookups that many forget

The 74.5 megawatt is designed with 300,000 solar panels that will produce electricity to power 15,000 homes.09a414df34ae779ad71a1ffcfde89ef4

cost for residential solar systems has fallen more than 60% over the last decade.

The system if deployed on mars would be 43% of what we see here.

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#614 2022-02-07 09:16:28

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 4,858
Website

Re: Going Solar...the best solution for Mars.

This was in today's AIAA "Daily Launch" email newsletter.  It details the increasingly-fatal effects of dust accumulation limiting power production on the Insight Mars lander.  It specifically blames dust storms for this. 

Such were rather small dust storms;  history says they can be planet-wide,  and last for months. That is the weakness of solar power on Mars,  and it shows exactly why you really use solar as the extra atop a "base load" of nuclear.  --  GW

InSight Recovers From Safe Mode; Mission May Still End Within A Year

Space News (2/5, Subscription Publication) reported that “NASA’s InSight Mars lander has recovered from a safe mode caused by a dust storm in January, but the project’s leader says the mission is still likely to end within a year because of declining power levels.” In a presentation at February 3’s meeting of the Mars Exploration Program Analysis Group, Bruce Banerdt, principal investigator for the InSight mission, “said he expected the lander to resume normal operations Feb. 5 after going into a safe mode Jan. 7.”


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#615 2022-02-07 11:18:00

kbd512
Administrator
Registered: 2015-01-02
Posts: 5,842

Re: Going Solar...the best solution for Mars.

We've known about the deleterious effects of dust accumulation for quite some time.  It significantly affects solar array output here on Earth where we're 50% closer to the Sun than Mars is, on average.  This latest study is merely more proof that dust accumulation is not something that we can ignore, because it so drastically affects the utility of any solar-based power system.  Dust is a serious problem for machinery and electronics, as is water.  Therefore, considerable effort will be devoted to ameliorating these problems.  Furthermore, simply "laying the panels on the ground" to reduce weight is an egregiously bad idea.

When I was arguing with Louis about this inconvenient fact of life on Mars, I made a good faith effort to come up with a lightweight solar panel backer board using aerospace composites and a highly sophisticated CNT / BNNT wiring and insulation scheme to reduce wiring mass, but I still couldn't arrive at a mass comparable to nuclear power after the storage subsystem was included in the final mass tally.  We wound up with a bare minimum of 1 order of magnitude more mass than a nuclear reactor producing equivalent output.  That means we'd need batteries or another storage medium with an energy density comparable to liquid hydrocarbons to produce a complete 24/7/365 energy provisioning solution comparable to a nuclear power system, though still more massive than straight nuclear reactors.  That mimics what we see here on Earth, so it should not be surprising that a place 50% more distant from the Sun can do no better, no matter what technology we throw at the problem.  The backer boards would keep the panels 1m to 2m off of the ground, away from the clingy electrostatically-charged dust on the ground, and we would need a team of robotic cleaners, toiling away 24/7 cleaning off the panels using the equivalent of a feather duster.  Even if the solar panels, electronics, and battery storage subsystem were all 100% efficient (no losses of any kind), that doesn't change the math in favor of solar power.  At that point, the end results of this exercise should focus on the question of what the real argument against nuclear power is.  It's not math-based, therefore not science-based, therefore related to belief or ideology.

I don't have any qualms about using solar power, and my own home is partially solar powered, but it cannot provide 24/7/365 power without an enormous mass and energy investment that is impractical for use in fledgling colony on Mars.  If I didn't believe that solar panels could provide useful power, then I wouldn't pay for them.  However, in less than 1 year of time, 16 of the 76 solar panels on my roof are now disabled due to electronics (power inverter and/or wiring) failures, according to the installers of that system, and they are currently awaiting parts to replace the defective electronics and wiring.  They claim it will take about 2 weeks to obtain replacements, but time will tell us how closely their assertion correlates with reality.  From past experience, I wouldn't bet on having replacements in less than a couple months.  Each power inverter contains a fuse to protect the inverter electronics and panel, but since each unit is totally sealed, it must be returned to the factory, disassembled, and then refurbished (fuse and seals replaced) prior to reuse.  They're built that way to prevent ingress of dust and water contamination.  While highly effective in that regard, it also makes repair more difficult and time consuming.

As such, this nonsense about photovoltaics and batteries becoming the backbone of a near-future energy supply, either here on Earth or on Mars, needs to be examined very critically, and without any rosy prognostications about future technology or ideologically-based arguments that ignore current technological reality in favor of "futurism".  Thermal power plants are not "faddish" in nature.  They exist for very good reasons.  At best, my assertion is that wind and solar can be treated as surplus intermittent power that should be used to create an "as-flat-as-practical" demand curve so a thermal power plant (either solar thermal or nuclear thermal) can backstop the intermittent power by supplying baseload power.  Thermal power plants are big / expensive / labor-intensive, but they're also incredibly reliable and capable of the one thing that wind turbines and photovoltaics are not- supplying power all the time no matter what the weather or time of day happens to be.

There's no real issue with running surpluses during the day, so long as we have something productive for that surplus power to do.  I think the best use of energy surpluses is to store the power in the form of liquid hydrocarbon fuels.  We should also economize on fuel consumption for road vehicles by using smaller / simpler engines in simpler / lighter vehicles.  If we can generate enough surplus to consume atmospheric CO2 to synthesize storable hydrocarbon fuels, then we have a truly sustainable system.  We simply lack the technology to power practical heavy duty transport vehicles or aircraft using batteries.  Blimps and trains are the only practical solar powered vehicles, because they can be directly supplied with power using onboard solar panels, whereas nothing that rides on rubber tires or flies using aerodynamic lift ever could- and the larger / heavier the vehicle, the less practical this becomes, ruling out the use of all existing photovoltaics and batteries.

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#616 2022-02-07 16:22:32

GW Johnson
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From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 4,858
Website

Re: Going Solar...the best solution for Mars.

As cold as Mars is,  air conditioning is unlikely to be a factor in electricity demand.  But there will be a need for heating day and night,  pretty much around the clock.  It might be a little larger at night.  Maybe not.  Seasonably variable. 

During the nights,  most but not all the base personnel will be asleep.  A few keep watch,  and will need some lights.  That won't draw much.  It is during the day that everyone is up and busy and eating meals.  There will be electricity draws for cooking,  for laundry,  for communications and computers,  for power tools,  for electrically-powered heavy equipment,  etc. 

It is the making of oxygen and drinking water that must go on 24/7.  And if there is a propellant production activity,  that needs to go on 24/7. 
 
Point is,  there is a large "base load" of electricity draw on Mars,  larger for the population than here on Earth.  I would guess that the day/night variation in power draw is less than for Earth,  but still significant. 

What is smart to do is size the nuclear supply of electricity at a bit larger than the minimum nightly draw,  probably pretty close to the average-over-time.  Then you add enough solar to hit the max daily peak during the day,  and maybe just a bit more.  And you keep the dust swept off.  That minimizes the need for batteries,  minimizes the size of the nuclear plant,  and minimizes the mass of panels, controls,  and wiring.  All within the (hard) constraints of having enough on hand to get by,  even in the worst dust storms. 

After all,  daily demand will be reduced during bad storms,  because nobody is going outside to work under conditions like that.  The power draw for tools and especially heavy equipment,  will be much reduced,  lowering the daily peak.

GW

Last edited by GW Johnson (2022-02-07 16:24:43)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#617 2022-02-07 19:39:55

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 25,943

Re: Going Solar...the best solution for Mars.

The natural heating from equipment and cooking with a place that is well insulated may still need a little of both depending on what is happening but not like we are here on earth with the buildings which might not be so good for climate controlling. I currently live this in a poorly insulated split level ranch style home but since the cellar is so wet and cold we are only using the upper floor where we are able to stay above 50 'F with just the equipment use.

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#618 2022-02-08 10:37:25

Oldfart1939
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Registered: 2016-11-26
Posts: 2,300

Re: Going Solar...the best solution for Mars.

kbd512-
Your post #615 was a marvelous and well written summary of the shortcomings of Solar Power for use as the primary energy source on Mars--as well as here on Earth.
Robert Zubrin came to the same conclusion nearly 35 years ago, and he included a small nuke reactor in his Mars Direct proposal as a consequence.

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#619 2022-02-12 20:15:23

SpaceNut
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Re: Going Solar...the best solution for Mars.

This is the first that I have heard of this occurring.

Solar panels catch fire atop Mass. business, causing millions in damages

AATMiHC.img?h=768&w=1366&m=6&q=60&o=f&l=f

Makes one wonder what happened in the system to cause the panel to breakdown and to create the heat level as to cause metals to burn.

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#620 2022-02-12 20:17:35

louis
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From: UK
Registered: 2008-03-24
Posts: 7,208

Re: Going Solar...the best solution for Mars.

Lol! You lot never change.

We have huge experience of dust accumulation issues on Earth-based facilities which are often located in dusty desert regions which have frequent dust storms.

Mars Insight Lander was a stationary robot. It wasn't designed to shake off dust as far as I can see.  The mobile robots have done fantastically well continuing to be powered by solar over 12 years or more. They are able to shake off the dust easily.  When it comes to solar power facilities on Mars of course we will have dedicated robot cleaners as we do already on Earth.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#621 2022-02-13 19:25:27

GW Johnson
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From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 4,858
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Re: Going Solar...the best solution for Mars.

Louis:

Glad to see you back. 

Insight was not designed to shake off dust,  as you say.  That is one of two parts of the dust storm problem,  the other being reduction of insolation in an atmosphere obscured with dust.  Both effects act upon Insight.

Don't know anything about robot solar panel cleaners on Mars,  or about any plans to build such things,  but they would certainly be useful. 

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#622 2022-03-20 17:46:29

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 25,943

Re: Going Solar...the best solution for Mars.

tahanson43206 wrote:

Mars_B4_Moon just posted a link to news of an improved solar cell for space use.

Such a solar cell might be of interest to designers of Large Ships.



https://interestingengineering.com/spac … -panels-33

The statement adds that, "the IMM-β is also a radiation-hard cell with a power remaining factor of 87% after exposure to 1-MeV electrons at a fluence of 1E15 e/cm2 or equivalent of about 15 years life in GEO."

I note the projected 15 year lifetime in GEO.... Large Ship will be operating in the equivalent of GEO for most of it's service life, so solar cells chosen to support life aboard the ship must be chosen to survive deep space radiation for an extended period.

(th)

First off the panels are 33.3% efficient but the real deal closer is that they are 40% lighter and since we need about 3 times as many to provide the same energy as 1 panel does we are getting closer to being able to use solar from the mass reduction and energy efficiency improvement.

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#623 2022-03-20 19:15:24

louis
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From: UK
Registered: 2008-03-24
Posts: 7,208

Re: Going Solar...the best solution for Mars.

In virtually all the most habitable places on Earth - tropics and sub-tropics - we are already there with solar I would say. We just aren't quite at the point where we have reliable and cheap storage. But that is coming down the tracks for sure.

SpaceNut wrote:
tahanson43206 wrote:

Mars_B4_Moon just posted a link to news of an improved solar cell for space use.

Such a solar cell might be of interest to designers of Large Ships.



https://interestingengineering.com/spac … -panels-33

The statement adds that, "the IMM-β is also a radiation-hard cell with a power remaining factor of 87% after exposure to 1-MeV electrons at a fluence of 1E15 e/cm2 or equivalent of about 15 years life in GEO."

I note the projected 15 year lifetime in GEO.... Large Ship will be operating in the equivalent of GEO for most of it's service life, so solar cells chosen to support life aboard the ship must be chosen to survive deep space radiation for an extended period.

(th)

First off the panels are 33.3% efficient but the real deal closer is that they are 40% lighter and since we need about 3 times as many to provide the same energy as 1 panel does we are getting closer to being able to use solar from the mass reduction and energy efficiency improvement.

Last edited by louis (2022-03-20 19:15:58)


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#624 2022-04-27 12:43:58

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 3,206

Re: Going Solar...the best solution for Mars.

'Why solar energy can be a more effective way to power a mission on the surface of Mars than nuclear'

https://www.universal-sci.com/article/s … rs-mission

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#625 2022-04-27 19:15:38

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 25,943

Re: Going Solar...the best solution for Mars.

equator of Mars, such a solar-powered system would require transport of about 8.3 tons of mass to the red planet to generate the same amount of power that a mini nuclear power station would produce at 9.3 tons.

Not enough info

https://arxiv.org/pdf/2110.14757.pdf

flawed in trying to use max performance and calculated dust storm to calculate power store via water electrolysis

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