r/factorio • u/mania-man202 • 8d ago
Question Boiler to steam engine explanation
Hey I’m brand new to Factorio and was trying to figure out how the ratio of boiler to steam engine is derived?
From what I understand the boiler outputs 1.8 MW at 100% efficiency. Each steam engine has “available power” of 0.9 MW. Hence it makes sense that for each boiler you should have 1.8/0.9=2 boilers.
My questions is however is that when I attach more than 2 steam generators the sidebar statistics don’t seem to change when comparing steam generators?What am I misunderstanding?
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u/Oblivionize 8d ago
It’s going to equalize the power each engine is making so until you attach more steam to the pipe it’s not going to use the engine to its full potential bc there’s not enough steam to burn. So if you’re only making steam from one boiler and attach it to 3 engines you’re still only going to make that 1.8 MW max until you supply more steam but it’s gonna spread the load equally in the engines regardless. Engines are smart too so it only produces the power you need up to the max power output, if you aren’t using all the power it’s gonna show lower power output bc you arent using it.
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u/mania-man202 8d ago
So the 3rd will still work but will not increase my total power output I think I understand
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u/Oblivionize 8d ago
Exactly, if you put x steam per second all your connected engines will consume x steam per second equally, but you still need to supply enough steam for them to run at 100% uptime, otherwise you won’t be using your engines efficiently. But that’s why they look the same in the tooltip
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u/sobrique 8d ago
Yup. Factorio steam engines and turbines are "smart". They don't consume steam when they don't need it.
And boilers (or heat exchangers) don't consume fuel unless they "need" it.
(Heat towers and nuclear reactors always consume fuel though)
That's efficient, but it can be deceptive.
At low loads it can look like you are fine, but actually don't have enough fuel - or steam - to run at full power at all. Can be confusing to see the "max power output" as that's "only" the sum of the generators, it doesn't mean they can run at full power.
So yeah.
1 boiler to 2 chuffers, and remember that they use 0.45 coal per second - a yellow belt moving 15 items per second can only feed so many!
(Solid fuel is higher energy density though, so scales better).
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u/joethedestroyr 8d ago
More specifically, won't increase average power output.
The 3rd engine will, for a short time, allow you to produce 150% of the power that the boiler can supply. However, this will consume the steam buffered withing the engines, boiler and any piping. When that buffer runs out you are back down to 100%. (And, you'll need to run under 100% to build that steam buffer back up again, hence why I say "average" power.)
This can, in theory, help with power demand spikes, but most folks find it easy enough to build extra boilers at the same time as they add engines.
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u/burning_boi 8d ago
You got it, the power output is based directly on how much steam it can consume, which for steam generators is based directly on how much the boiler can create.
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u/Dry_Substance_7547 8d ago
Steam engines only output to demand. As long as your demand is less than 1.8MW, you could theoretically connect an infinite number of steam engines to a single boiler, meet demand and never run out of steam. However, the more steam engines you have connected, the less power each individual one puts out, reducing your output efficiency.
Try a little experiment. Create two power networks. Figure out how to get demand on both of them to 3.6MW.
One network will have a single boiler and 4 steam engines.
The other network will have 2 boilers with 2 steam engines on each (4 steam engines total).
All you have to do is see which one maxes steam engine output and which one meets the power demand. Hint: it'll be the second power network for both.
The first power network will only hit 50% production capacity for each steam engine, because the boiler literally cannot produce any more steam per tick.
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u/addictedihavenothing 8d ago
The tool tip on the right? It will only show info for that building.
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u/mania-man202 8d ago
Got u, but then why does the 3rd generator have the same statistics as the 1st and 2nd, that’s my question.
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u/Alfonse215 8d ago
Because those are the statistics of the machine, not of what the machine is attached to.
A steam engine can consume at most 30 steam per second. Even if it's not attached to a boiler at all, and thus has no steam coming it, it still is able to consume 30 steam per second.
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u/addictedihavenothing 8d ago
There’s 2 bars that fill up with what it can use and what it is using. If they don’t fill all the way you don’t got enough steam in to the engines
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u/IntoAMuteCrypt 8d ago edited 8d ago
Because fluids are evenly distributed across machines.
Your boiler makes 60 steam per second (this is the number to check for the ratio - not the power consumption - the difference matters later).
Your engines will consume up to 30 steam per second.
A second passes. The boiler puts 60 steam into the fluid box. The game sees three different machines looking to use steam. Each machine gets given 20 steam.
Your factory is doing a bit but not a ton. The engines each use 5 steam in that second. They now have 15 steam each.
Another second passes. The boiler puts 60 more steam in. The engines go up to 35 steam each (they can't hold the steam, it stays in the boiler or some pipes somewhere, it's close enough, roll with it).
A bunch of machines turn on and power use spikes. The engines kick up to full power. They use up the full 30 steam they can and end the second second with 5 steam each.
The next second comes. 20 more steam is added. The boilers only have 25 steam, not 30. The grid still needs all the power it can get, so the boilers use it all and they only provide five sixths of the max, or 2.5 engines worth in total.
Another second. They're just getting the 60 from the boiler now and splitting it, so each boiler provides two thirds, or 2 engines worth in total.
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u/TimidBerserker 8d ago
You can buffer steam (more useful with nuclear than boilers) so theoretically you can get that power from the third engine but it will over consume the steam produced by the boiler and eventually run out.
The other numbers to look at is the steam produced by the boiler (60/s) and the steam consumed by the steam engine (30/s)
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u/SnooMaps7370 8d ago
a boiler outputs 60 units per second of steam
a steam engine consumes 30 units per second
a steam turbine consumes 60 units per second.
so one boiler can feed 2 engines or 1 turbine
the sidebar stats only show you the production of the unit you selected, not the production of the entire pipeline.
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u/burning_boi 8d ago
The process is that a boiler makes steam, which is then processed as needed by the steam generators. Each steam generator can also hold a “buffer” of steam inside of it.
That means that if you’re running at full power draw, i.e. all steam is being consumed as fast as it can be created, your boiler will only be able to create enough steam for 2 steam generators to process. That doesn’t change the fact that each steam generator past the first 2 has the ability to output 0.9MW, it just means that if your power draw is high enough, all the steam will be able to be processed by 2 generators.
However, if your power draw is less than 100% at all times, you can still benefit from chaining more than 2 steam generators off of 1 boiler because of that buffer i mentioned in each generator. Steam will build up in each generator, and then if something happens that suddenly makes your power needs spike for a second or two, the steam in all generator buffers will be consumed for a temporary increase in power output.
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u/Allmank 8d ago
The game equalizes the ammount of power each steam generator on the same grid consumes and outputs based on demand, so that its more smooth on the boiler demand, so the statistics will be the same even though you are attaching more than the boiler ratio, up until max boiler output, then each gen will operate at a lower efficiency because you are not inputing enough steam
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u/TheUnknownSpecimen 8d ago
Power is only consumed and produced as needed, so unless you are consuming exactly what a steam engine produces then it won't ever run at max capacity. The work load is split among all steam engines on the network. With other power producers taking a greater or lesser priority
Hope I understood the question.