How bright is this planet anyway?

[Khyron]

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.

[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. Which is really possible, cause it is a game.

[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.

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.

[bigyihsuan]

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

[ssilk]

Interesting, but where did you take the speed from? Never heard of it...

[bigyihsuan]

Interesting, but where did you take the speed from? Never heard of it...

Tooltip from hovering over the train

[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)

[bigyihsuan]

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?

[Khyron]

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.

[Khyron]

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?

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?

[DaveMcW]

Since the earth-based solar industry prefers to use kWH, we can convert Factorio data to that.

42 kW per solar panel * 24 hours / 9 m^2 = 112 kWH/m^2 per day.

112 * 365 = 40,880 kWH/m^2 per year.

Compare to some earth data:
http://www.pveducation.org/pvcdrom/prop ... -radiation
http://www.greenrhinoenergy.com/solar/r ... idence.php

[MadZuri]

I must say that I love the way this conversation has gone. I started the post as a way to conceptualize the homework I was doing in my energy systems and the environment class in my nuclear engineering curriculum. In real life, solar and wind have a max of about 30% utilization factor. That means you can only use on average about 30% of the installed maximum power that those systems provide, and you still need a baseline power system. You can't really choose when wind kicks in, and solar only works on clear days half the time (pretty close to a sine wave, really). That kWhr unit is an endless source of frustration for me. It is a unit of energy, equal to 3600 kJ. Power for most plants is in MW. You gotta multiply time * power * utilization factor to get the average, but they charge by energy, in kWhr. Long story short, if you want minimal impact on carbon emissions, nuclear is the only way to go. Supplement it up to 15% solar, 15% wind, and that is about it. Energy storage is HARD. Current technology almost exclusively is in the form of pumping large volumes of water into reservoirs for storing energy. We don't have accumulators IRL. Maybe eventually, but now... not so much. Be glad the game is the way it is, and that renewable is a viable form of baseline power production. Real life isn't so kind.

Add to my struggle that I live in the US, and that most things are in units of BTU's, kCals, F, and pounds-feet and you should understand my frustration with the topic.

[Khyron]

...and you still need a baseline power system.

... says conventional wisdom. Challenge the status quo, man. We can do better! Part of the problem here is that we arrive at this need for a baseload power system if we start by assuming a) we will need a ubiquitous power grid and b) power companies will store the power for nighttime use. Apparently nobody told the consumer that because you can get residential solar systems which include an array of 12v lead-acid batteries to power your needs overnight and be fully off-grid.

Alright, so there are problems with that. But we're still at an infancy stage in terms of power storage technologies. There simply hasn't been a mass-market demand for this technolgy until very recently. Look what mobile phones and laptops have done for battery technology in the past 10 years. Fully electric cars will be the next big push. Personally I love the idea of massive banks of flywheels (in a sort of steam-punk kind of imagining) but again that has challenges (some of which are being tackled by materials engineering). But some future technology would be awesome.

We don't have accumulators IRL. Maybe eventually, but now... not so much.

Sure we do. Capacitors. Rechargeable batteries. The problem is a) charging them is a lossy process (put more in that you get back out) and b) they physically degrade over many charge/discharge cycles.

Add to my struggle that I live in the US, and that most things are in units of BTU's, kCals, F, and pounds-feet and you should understand my frustration with the topic.

You started it. Maybe your generation will make the US change to le systeme international d'unites. Eww, French... gross. And upgrade your bloody 110v low efficiency domestic grid, geez...

[cpy]

USA is our medieval fair fun place, where they use old inefficient power grids, use ancient measurement units, they use this illogical nonsense to preserve history for future generations, but i prefer old stuff to be written in books or digital storage, but whatever.

[JimiQ]

I recommend this blog of american physics professor Tom Murphy. It contains lots and lots of calculations about solar and other forms of energy (pretty much every form we know) and multiple forms of energy storage (from pumped air through water reservoirs to lead-acid batteries)

[Psycho0124]

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. Which is really possible, cause it is a game.

Yep. Modern cells are really only about 20% efficient. They only absorb a limited spectrum, have huge losses to heat and reflection, suffer from the resistance in the conductors in the cells, allow some photons to pass through, etc. Future solar technology is going to have a vastly different efficiency rating. It may use layers of more than one semiconductor material to absorb more of the electromagnetic spectrum, have built-in heat-> electricity conversion technology, have fancy anti-reflective coatings, etc.. The efficiency variable will ruin any attempt to calculate the brightness of the planet based on the power produced.

http://solarcellcentral.com/limits_page.html
^ Neat read on the limited efficiency of modern solar technologies.

[SteelGiant]

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. Which is really possible, cause it is a game.

Yep. Modern cells are really only about 20% efficient. They only absorb a limited spectrum, have huge losses to heat and reflection, suffer from the resistance in the conductors in the cells, allow some photons to pass through, etc. Future solar technology is going to have a vastly different efficiency rating. It may use layers of more than one semiconductor material to absorb more of the electromagnetic spectrum, have built-in heat-> electricity conversion technology, have fancy anti-reflective coatings, etc.. The efficiency variable will ruin any attempt to calculate the brightness of the planet based on the power produced.

http://solarcellcentral.com/limits_page.html
^ Neat read on the limited efficiency of modern solar technologies.

The efficiency thing isn't really so much of a problem: even at 100% efficiency, the Factorio solar cells are generating so much energy that the light intensity over the entire planet is so high that liquid water would be immediately split into hydrogen and oxygen. The fact efficiency will be lower than 100% just makes this effect even worse.

[Koub]

The efficiency thing isn't really so much of a problem: even at 100% efficiency, the Factorio solar cells are generating so much energy that the light intensity over the entire planet is so high that liquid water would be immediately split into hydrogen and oxygen. The fact efficiency will be lower than 100% just makes this effect even worse.

Technically, even on Earth, at sea level, and ambient temperature, an infinitesimal fraction of the water spontaneously breaks into H2 and O2. It's an equilibrium.
Now, under same conditions, if you want to achieve thermolysis for good, you'll need to be around 2700ish°C. I am way too lazy to calculate if Factorio's world reveives enough light to have 2700°C on its surface, but I bet not.

[MadZuri]

I'll do the math for you. A temp of 2700C would have a black body radiation of about 4 million w/m^2, a bit much for our example. If we assume the solar panel efficiency is 50% (damn near a theoretical maximum for converting photons to usable electricity) and surface albedo of 30% (about the same as earth), the ground would need to radiate 6.53kW/m^2 with a surface temperature of about 300C. I took into account the daily average solar panel output being 42kW. I neglected the greenhouse effect, which would raise the surface temperature by a fair bit. So there you go. For factorio's solar panels to produce as much energy as they do, the surface temperature would be at a Minimum 300C. For giggles I'll assume that the solar panels are 100% efficient and surface albedo is 50%, and neglect greenhouse effect again.... That's about 177C.

[Psycho0124]

Hahah.. Alright then. Visible light (photons) only accounts for ~40% of the energy spectrum emitted by our sun though. If we assume we have a high-tech panel that can absorb the entire electromagnetic spectrum, and a star with a vastly different spectral irradiance curve, could we have a reasonable surface temperature?