[Spaceships] Query: Area of a Solar Panel Array

[DaltonS]

Is there a fixed area per ton of Solar Panel Array or is it the square of the ship's SM+3 length per system? (This will be useful when mapping my Martian “Gas” Station.)

Dalton “who likes mapping what he designs and vice versa” Spence

[Ejidoth]

A fixed area per ton would be more realistic, but you can run into problems if you try to work out realism for Spaceships solar arrays, as they seem to be implausibly efficient.

Given that, using the SM+3 that's used for targeting them seems like the most workable compromise, since it will prevent contradictions with other game mechanics.

Probably closer to one half the square of that length rather than the full square of that length, though, for area: remember, when converting SM to surface area, that the default assumption for SM 0 is a human-ish target that's at least twice as tall as it is wide.

[Anthony]

Realistically, you're looking at upwards of a square meter per kilowatt, and given that a SM+5 (1.5 ton) major battery outputs 10 MJ per 10s (per 5s if improved) it seems unlikely that a power plant is less than 2 megawatts per ton..

A SM+5 solar array is at least 3,000 square meters, or about a 100 meter radius if it's circular. That's a 200m diameter (SM+12) with another +2 for being a circular object, so SM+14. A decent rule of thumb is

Radius: (SM*1.5)+3.
SM: (SM*1.5)+7.

Thus, a SM+10 solar array has a radius of about a mile (+17) and has a size modifier of 22.

[DaltonS]

Originally Posted by Ejidoth

A fixed area per ton would be more realistic, but you can run into problems if you try to work out realism for Spaceships solar arrays, as they seem to be implausibly efficient.

Given that, using the SM+3 that's used for targeting them seems like the most workable compromise, since it will prevent contradictions with other game mechanics.

Probably closer to one half the square of that length rather than the full square of that length, though, for area: remember, when converting SM to surface area, that the default assumption for SM 0 is a human-ish target that's at least twice as tall as it is wide.

Okay, lets go with that. My SM+11 Martian “Gas” Station has three Solar Panel Arrays (one won't cut it at 1.5 AU) which have an SM+14 targeting modifier. That corresponds with a 1,500 foot length. Squaring that and multiplying by 3/2 gets me 3,375,000 square feet or 77.47934 acres. Wow, talk about a solar farm! Keeping it dusted would be … very hard!

Dalton “And think of the Windex!” Spence

[Anthony]

Originally Posted by DaltonS

Okay, lets go with that. My SM+11 Martian “Gas” Station has three Solar Panel Arrays (one won't cut it at 1.5 AU) which have an SM+14 targeting modifier. That corresponds with a 1,500 foot length. Squaring that and multiplying by 3/2 gets me 3,375,000 square feet or 77.47934 acres. Wow, talk about a solar farm![/I] Spence[/SIZE][/FONT][/RIGHT]

Hm. Compare to Topaz solar farm at 3,500 acres. Actually, that's not an unreasonable size for your gas station, 3,500 acres is 14 million square meters, and 3 x SM+11 power plant should be on the order of 9 gigawatts (space-based systems are likely to be far more compact than ground-based).

[DaltonS]

Originally Posted by Anthony

Hm. Compare to Topaz solar farm at 3,500 acres. Actually, that's not an unreasonable size for your gas station, 3,500 acres is 14 million square meters, and 3 x SM+11 power plant should be on the order of 9 gigawatts (space-based systems are likely to be far more compact than ground-based).

Actually according to the rules from GURPS Classic: Vehicles page 96, the power generated by that area of "solar cells" should be 270 MW on Earth which would translate to 120 MW on Mars. (The rate was 0.08 kW/sf if you are wondering.)

Dalton “A factor of 75 isn't too much, is it?” Spence

[Anthony]

Originally Posted by DaltonS

Actually according to the rules from GURPS Classic: Vehicles page 96, the power generated by that area of "solar cells" should be 270 MW on Earth which would translate to 120 MW on Mars. (The rate was 0.08 kW/sf if you are wondering.)

Dalton “A factor of 75 isn't too much, is it?” Spence

Yes, but one energy point at SM +11 is almost certainly not less than 3GW.