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How bright is this planet anyway?

Posted: Tue Mar 17, 2015 5:42 pm
by MadZuri
I was doing homework for one of my classes, and I thought I'd do the same calculations for factorio! MY homework assignment was about figuring out how much land it would take to power the US entirely off of solar. Given data included a peak incoming solar radiation of about 1350w/m^2. (outside the atmosphere)

So, what is Factorio's incoming solar radiation? I'm assuming that each grid square is 1 m^2, and they have better tech than we do. So at 50% efficiency, to produce a max of 60 kW with an area of 9 m^2... the incoming solar radiation would have to be 13.3 kW/m2. That is about 10x Earth's solar radiation. Just thought to share some quick calculations.

edit: I dropped a 0 in there, i fixed the math.

Re: How bright is this planet anyway?

Posted: Tue Mar 17, 2015 5:53 pm
by DaveMcW
That explains why solar panels are so overpowered. :)

Re: How bright is this planet anyway?

Posted: Tue Mar 17, 2015 6:08 pm
by Omgalof
that also explain why he never take the space suit out.

Re: How bright is this planet anyway?

Posted: Tue Mar 17, 2015 6:15 pm
by MadZuri
Yeah, on earth nominal/affordable solar cells provide 150w/m2 electrical, but on factorio they produce 6667w/m^2. If you assume we use the same technology, factorio is ~45x brighter than earth. That or the scale of gameplay is deceptive. I really doubt a refinery is 5m x 5m big...

Re: How bright is this planet anyway?

Posted: Tue Mar 17, 2015 6:39 pm
by SHiRKiT
MadZuri wrote:Yeah, on earth nominal/affordable solar cells provide 150w/m2 electrical, but on factorio they produce 6667w/m^2. If you assume we use the same technology, factorio is ~45x brighter than earth. That or the scale of gameplay is deceptive. I really doubt a refinery is 5m x 5m big...
Nor that the human is taller than the assemblers, but this Factorio. Everything can happen win Factorio.

Re: How bright is this planet anyway?

Posted: Tue Mar 17, 2015 9:08 pm
by hoho
What if it's a huge mecha instead of a human? It would at least explain being able to carry several wagons worth of stuff with it all the time.

Re: How bright is this planet anyway?

Posted: Tue Mar 17, 2015 11:10 pm
by ssilk
We can assume, that 1 tile = 1m² , cause too much things are matching together with that measure. Any other leaves more question-marks. :)

Re: How bright is this planet anyway?

Posted: Wed Mar 18, 2015 3:03 am
by Khyron
I agree with the size/scaling and efficiency discussed above, but there is some wiggle room in the other factors:

On a clear day in Melbourne, Australia (ie: pretty far South) we can get over 2kW/m2 between 11am and 3pm. Without checking I'd expect it gets near to 3kW/m2 for a longer part of the day at the equator.

Possibly a more important factor for a different planet would be the spectral distribution of the primary. Higher wavelengths yield more power. So maybe it looks similarly lit to Earth due in the visible spectrum, but there's more ultra violet and above. I'm not sure what range PV cells can work in though...

At least, that's the explanation I'd go with :ugeek:

Re: How bright is this planet anyway?

Posted: Wed Mar 18, 2015 3:41 am
by MadZuri
^^ what Ssilk said that is most definitely true. Everything from shown velocities to bot power consumption to the head loss in pipes confirms that. Even the code lists it as meter/tiles interchangeably. Conclusion: the factorio world is somewhere between 10 and 45 time brighter than earth. Either that or solar produces so much power for gameplay balance. :D This just makes me think about all those mods that makes solar even MORE powerful... they are absolutely absurd! I blame my engineering education for this.

Re: How bright is this planet anyway?

Posted: Wed Mar 18, 2015 3:46 am
by MadZuri
Khyron wrote:(snip) Possibly a more important factor for a different planet would be the spectral distribution of the primary. Higher wavelengths yield more power. So maybe it looks similarly lit to Earth due in the visible spectrum, but there's more ultra violet and above. I'm not sure what range PV cells can work in though...

At least, that's the explanation I'd go with :ugeek:
That would certainly explain how the creepers evolve so fast. I wonder if it is a binary system? That would explain how the daylight cycle is so skewed to favor day over night.

Re: How bright is this planet anyway?

Posted: Wed Mar 18, 2015 6:39 am
by Khyron
MadZuri wrote:That would certainly explain how the creepers evolve so fast. I wonder if it is a binary system? That would explain how the daylight cycle is so skewed to favor day over night.
Hm... well...

UV mutating the DNA of terrestrial life is one thing but who knows how some other life evolves, adapts, mutates, etc. Do they have DNA or anything even like it?

And as for day/night cycles... it could be due to axial tilt. Or binary stars as you suggest, but if that were the case we should expect to see different brightness levels and colours reflected off the surface.

Re: How bright is this planet anyway?

Posted: Wed Mar 18, 2015 8:23 am
by ssilk
Sorry, but a world that bright would just cook. Even two times brighter will kill all life. Indeed the amount of solar power is limited to a relative small zone around a sun (relative in astronomical measures):
http://en.wikipedia.org/wiki/Circumstel ... table_zone

So the logical conclusion is: The solar panels must be somehow much, much, much more efficient. :geek: Which is really possible, cause it is a game. :D

Re: How bright is this planet anyway?

Posted: Wed Mar 18, 2015 8:42 am
by DaveMcW
Even with 100% efficiency, you need 6.67 kW/m^2. That is 6 times as bright as the earth's equator at noon.

Khyron wrote:On a clear day in Melbourne, Australia (ie: pretty far South) we can get over 2kW/m2 between 11am and 3pm. Without checking I'd expect it gets near to 3kW/m2 for a longer part of the day at the equator.
That is 2 kilowatt-hours/m^2. You need to divide by 4 hours to get the average radiation, 0.5 kW/m^2.

Re: How bright is this planet anyway?

Posted: Wed Mar 18, 2015 10:30 pm
by bigyihsuan
ssilk wrote:We can assume, that 1 tile = 1m² , cause too much things are matching together with that measure. Any other leaves more question-marks. :)
Has anyone attempted to calculate how big a tile actually is? We have a confirmed max speed of a single locomotive, so I think rapidly taking screenshots and counting how many tiles pass in a certain amount of time, and divide that by the speed, to get how big a tile is. I think that's how it works.


EDIT: I'm guessing you could count how many tiles pass in one second, and see how it relates to the speed in m/s.

So:

Code: Select all

tiles/s = 259.2 km/s --> 72 m/s
tiles/s = 72 m/s
tiles = 72m         //cancel out seconds
tiles/tiles = 1m/tiles
1 tile = ??? m

Re: How bright is this planet anyway?

Posted: Wed Mar 18, 2015 10:49 pm
by ssilk
Interesting, but where did you take the speed from? Never heard of it... :)

Re: How bright is this planet anyway?

Posted: Wed Mar 18, 2015 10:52 pm
by bigyihsuan
ssilk wrote:Interesting, but where did you take the speed from? Never heard of it... :)
Tooltip from hovering over the train

Re: How bright is this planet anyway?

Posted: Wed Mar 18, 2015 11:10 pm
by DaveMcW
You will find the train moves 72 tiles/s.

Code: Select all

/c game.player.print("x:" .. game.player.character.position.x .. " y:" .. game.player.character.position.y .. " s:" .. game.tick/60)

Re: How bright is this planet anyway?

Posted: Thu Mar 19, 2015 12:09 am
by bigyihsuan
DaveMcW wrote:You will find the train moves 72 tiles/s.

Code: Select all

/c game.player.print("x:" .. game.player.character.position.x .. " y:" .. game.player.character.position.y .. " s:" .. game.tick/60)
Well there you have it. Every tile is 1 meter squared.

So transport belts are a meter, and the splitters are a ridiculously wide piece of machinery? Why not? :D

Re: How bright is this planet anyway?

Posted: Thu Mar 19, 2015 2:46 am
by Khyron
DaveMcW wrote:That is 2 kilowatt-hours/m^2. You need to divide by 4 hours to get the average radiation, 0.5 kW/m^2.
Nope. I meant what I wrote, which is why I used kW/m2 instead of kWh/m2.

However, my source had bad data. Our peak irradiance is more inline with OPs working value of 1kW during our summer.

Re: How bright is this planet anyway?

Posted: Thu Mar 19, 2015 2:53 am
by Khyron
bigyihsuan wrote:Well there you have it. Every tile is 1 meter squared.

So transport belts are a meter, and the splitters are a ridiculously wide piece of machinery? Why not? :D
I'm waiting to see how far down the rabbit hole this thread goes... If a 2m x 1m piece of machinery requires 16 iron to build, how much does each piece of iron weigh? If an inserter only uses 13kW for whatever duration to move a piece of iron 2 meters, what must the gravitational strength of the planet be? :lol: