02-25-2018, 03:19 AM | #31 | |
Night Watchman
Join Date: Oct 2010
Location: Cambridge, UK
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Re: [Spaceships] Antimatter Factory
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02-25-2018, 09:42 AM | #32 | ||
Join Date: Oct 2008
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Re: [Spaceships] Antimatter Factory
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So taking a say SM 11 fission reactor for $100 million, and the 1.5% costs for maintenance, bank loans and other costs makes the costs $1.5 million/month. SM 11 power point seems to be 10 GJ weapon shot every 20 seconds for normal weapon and one every 10 seconds for improved, so assuming normal is 25% efficient and improved 50%, that is 40 GJ/20 seconds or 2GW. So the power plant would produce 24*30*2 GW-h/month= 1440GW-h or 1.44 million MW-h for that 1.5 million cost. So one on site power production using space ships prices would give a cost of just over $1/MW-h. So that is a *30 improvement in cost for the electricity, we would then only need additional efficiency to cover the cost of the AM production facility, profit, transporting and such over your 0.00833% efficiency to reach spaceship prices. Say an efficiency increase of order of magnitude *2 to *8 maybe. |
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02-25-2018, 06:53 PM | #33 |
Join Date: Feb 2016
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Re: [Spaceships] Antimatter Factory
Energy is insanely cheap in Spaceships. The price of the fission reactor is $0.1/W, which is ridiculous cheap, considering that non-mobile fission reactors are 10/W. Solar panels are also laughably cheap at $0.16/W, considering that they cost $5/W before you subtract an average of $3.50/W in grants and tax incentives given by the federal, state, and local governments in the USA. In reality, SM+10 fission reactors should cost $3 billion, not $30 million, and solar panels should have a cost $1.5 billion at SM+10, if you do not receive subsidies and grants.
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02-25-2018, 09:13 PM | #34 |
Untagged
Join Date: Oct 2004
Location: Forest Grove, Beaverton, Oregon
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Re: [Spaceships] Antimatter Factory
If you use the posters' estimates of power points, then you hit the problem of solar panels producing far more energy as would be realistically available. They're obviously written to make them slightly competitive with fission reactors, etc.
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02-25-2018, 09:37 PM | #35 |
Join Date: Feb 2005
Location: Berkeley, CA
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Re: [Spaceships] Antimatter Factory
The power to weight ratio isn't absurd -- it's probably easier to get 1 kW/kg out of solar than it is out of nuclear. The problem is size. A SM +5 ship (30 tons, 1,500 kW) needs at least 1500 square yards for 1 pp. The actual cross-section of a SM +5 ship is probably something like 75 square yards, to get 1500 square yards you need to go up to SM +9, and realistic efficiencies result in it being about SM +11. This gets worse as you go up SMs -- a decent rule of thumb would be to multiply SM by 1.5 and then add 4, rounding up, for the SM of the solar array.
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02-25-2018, 09:50 PM | #36 |
Join Date: Feb 2016
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Re: [Spaceships] Antimatter Factory
If we use an estimate of 30 kW of electricity production per metric ton of spacecraft mass per power point, the minimum realistic size of a solar panel would be around 120 square meters per metric ton of spacecraft per power point at TL8 (assuming 19% efficiency) or 60 square meters per metric ton of spacecraft per power point at TL9+ (assuming 38% efficiency). If we also assume a minimum mass of 0.75 kg per square meter, the minimum mass for a SM+10 solar panel should be around 900 metric tons at TL8 (two components per power point) or 450 metric tons at TL9+ (one component per power point). Anything less robust than 0.75 kg per square meter (75 milligrams per square centimeters or the same mass as a postage stamp per area) will probably not survive any meaningful acceleration.
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03-05-2018, 10:07 PM | #37 | |
Join Date: Feb 2007
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Re: [Spaceships] Antimatter Factory
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03-06-2018, 08:13 AM | #38 | |
Join Date: Aug 2007
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Re: [Spaceships] Antimatter Factory
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Spaceships' adoption of mass as its' sole significant measurement makes the fuel/delta-V issues work out right for realistic drives. However no formula basing solar power generated on mass will work out right. Solar power should be based on surface area and not mass. As ships get larger their ratio of surface area to mass will shrink so attempts to use solar power will require increasingly large arrays added on. Historical/Real World spacecraft have relied on unfolded arrays anyway rather than panels covering only the outside hull. As with most of Spaceships realism issues it arises out of trying to extend a marginal/niche real world technology to give it general usefulness. Most users would never encounter the problems.
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03-06-2018, 09:48 AM | #39 |
Join Date: Feb 2016
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Re: [Spaceships] Antimatter Factory
I always assume that Solar Panel Array are deployable arrays that retract during combat and planetary operations.
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03-06-2018, 10:46 AM | #40 | |
Join Date: Aug 2007
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Re: [Spaceships] Antimatter Factory
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<shrug> I went back and checked and all the basic rules text says is that a Solar Panel Array is an exposed system and is not protected by armor. There certainly didn't seem to be anything about it changing the vehicle's SM. So not a fantastically realistic design option and I wouldn't use it as a source for hard numbers.
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