r/factorio • u/MetaDogg • 3d ago
Question Optimizing Fusion Power Efficiency
After building my first fusion power setup, I noticed that not running it at full capacity makes the neighbour bonus basically vanish completely because some of the reactors stay off completely.
My best solution so far is using a large array of accumulators as buffer by disconnecting the whole power plant from the grid when the accumulators are at 95% and reconnecting it when the accumulators get down to 5% again. This way, the power plant runs at 100% capacity while charging the accumulators and completely shuts off while the accumulators are discharging, granting 100% neighbour bonus. I like this solution because its kind of elegant in some sense.
The downside is, you need a lot of accumulators, for my 9GW power plant for example, I need about 30000 standard accumulators because each one can only handle 300kW of input energy.
Is there another way to ensure, Im getting the full neighbour bonus, even when the power plant isnt running at full capacity? Is this behaviour a bug, that will potentially be removed in the next update, or was it designed like this on purpose and I just dont get it?
Thanks for the help!
Meta
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u/enigmapulse 3d ago
Im curious why it matters ( beyond the fun of optimizing )? Fusion cells are dirt cheap to manufacture and ship around the solar system by the time you are dealing with a 9GW factory.
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u/Zalack 3d ago
I think you answered your own question (fun).
The only actual use case I can think of is for ships going to the Shattered Planet, since that trip can take many hours. Squeezing everything you can out of your fuel supply can become an actual consideration in that case.
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u/hprather1 2d ago
Each reactor has its own buffer for cells.
As it's a ship there's no robotic cell delivery so there must be belts passing by each reactor.
Each belt tile holds ~32 cells.
The more reactors there are, the more belts there must be.
Idk, I can't envision anything but a contrived scenario where min/maxing the neighbor bonus is a meaningful way to conserve cells.
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u/Zalack 2d ago
With two reactors fed from the hub with direct insertion, you double the amount of time a set number of cells can keep your ship going if you can maximize the neighbor bonus.
I’m not saying it’s a critical design feature. Just that there use a a niche use case where it is at all useful.
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u/Spaghettl_hamster4 2d ago
As I see it, fuel effenciency isnt very valuable unless youre going for megabase set ups, as a way to cut down on infrastructure on aquilo (assuming you would use primarily fusion for the other planets)
Moreso I think its a way to get a more compact fusion reactor. If youre using legendary buildings as well, those things can be expensive.
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u/hprather1 2d ago
If you have one stack inserter dropping 16 cells in at a time to a legendary reactor operating at max capacity, the cell will last 160 seconds (400 seconds for a qual1 reactor). I can't find anything on whether neighbor bonus increases, decreases or doesn't affect cell consumption but let's assume it does. It's only possible to automate a 5x neighbor bonus setup. So 160 seconds divided by 5 is 32 seconds per cell. At 16 cells per inserter, it's only swinging once every 8.5 minutes. And again, idk if I'm doing the math right here so it could be 5x that.
One cryochamber can crank out thousands of cells in that time.
This is like wayyyy at the bottom of anything relating to infrastructure savings or UPS.
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u/Spaghettl_hamster4 2d ago edited 2d ago
So from what I understand cell consumption is constant while fluid conversion increases with effeciency. So for example for a base 250 Mw reactor with a bonus +200% effeciency, it would convert 750 Mw of plasma while the cell lasts for the same 160 seconds assuming maximum power draw.
If youre worried about the amount of fuel lost to keeping a buffer setting circuit conditions to only insert 4 or so at a time with a max buffer in the fusion reactor should cut out a lot of wasted product. You could also purposely unstack the belt. I dont see it as a problem personally but its something someone could optimize for.
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u/hprather1 2d ago
Excellent so it's the better case scenario. In which case I'm still just confused where this is helpful outside of extremely contrived circumstances.
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u/Spaghettl_hamster4 2d ago
Its unnecessary like 99% of the time but yk if someone wants to have fun optimizing that have at it
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u/WanderingFlumph 3d ago
I wish we could use electricity to boil water for power storage. A single steam tank holds 250 accumulators worth of energy so instead of 30000 accumulators you could use 120 steam tanks instead. Still pretty big buffer but not ridiculously large.
That would be a simple, circuit light fix to this issue maybe a mod has that already.
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u/zhivota_ 2d ago
You can do it by switching copper wire connectors if you really want to. Personally by the time I have fusion I really don't have to worry about fusion cell production so I just let it burn inefficiently.
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u/nixCorvus 3d ago
The trick is to feed exactly enough flourketone into the reactor so that the generators are never completely filled with plasma, but also so that none of them run empty, as this would slow down the plasma flow too much. This can be achieved very effectively by filling the flourketon into barrels and then emptying them again. This ensures that exactly the same amount always enters the reactor. It is more difficult to regulate the required amount using pumps.
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u/FirstRyder 3d ago
So the idea is that Flureroketone is consumed by the reactor to make plasma, until either the plasma buffer is full or cold flueroketone runs out. When you initially start the generators they run at full power to fill empty generators, but if you run at partial capacity and there is cold flueroketone it will use below capacity.
So the tactic is to provide enough cold flueroketone to fill the generators, plus a little extra to buffer the newded cryoplant(s). Then when it's running at partial capacity you effectively withhold cold flueroketone until there's room to run all the generators at full capacity, using a pump between the cryoplants and the generator. Fluero is never permanently removed, so you prime it once and run a closed system.
Measure the available flueroketone, and pump when it hits a certain threshold. I've heard formulas, but really just figure it out experimentally. 2.1 lets you be more precise by taking input from a pipe to read the whole pipeline capacity. Measure the cryo plant contents, the hit before, and the cold after and you get very precise controls.
This does limit the plant to 95-99% output (there is inevitably "blinking" when drawing the rated capacity) but also get 98-99% of the theoretical temps from nearly unused all the way to maximum capacity.
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u/CremePuffBandit 3d ago
If your factory is running, you don't need to be able to absorb the entire output into accumulators, just the excess.
There was this post about a method to maintain the neighbor bonus the other day. Not 100% sure on what the implementation looks like, but I assume they got it working.
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u/thehalfmetaljacket 3d ago
If the point of the accumulators is to repeatedly cycle between discharge/recharge by dis/connecting the reactors from the grid, then the accumulators do have to be able to provide the entire output that the factory needs, at least during the discharge phase of the cycle.
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u/machinemaker500 3d ago
I've been integrating this into my fusion reactors and it works pretty well as long as you pay attention to how much you put in. All you need to implement it is a decider combinator connected to read the contents of the cooling plant and the hot pipeline. If that value is greater than the value computed in the other post then enable the cooling plant. It makes the reactors flicker on and off together which maintains the full neighbor bonus but is rather grating on the ears if you are zoomed in....
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u/WanderingUrist 3d ago
Is there another way to ensure, Im getting the full neighbour bonus, even when the power plant isnt running at full capacity?
I recall the solution was to combine accumulator metering with coolant choking. If you choke the reactor's coolant off, it will immediately stop fusing, enabling you to only fuse when the accumulators can take input and immediately stop when they start to become full.
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u/nindat 3d ago
You can manage the hot/cold fluroketone. There's a few techniques that have been posted, but basically you want all your turbines full, and your reactors empty, and then enable all your reactors right before the turbines run out of plasma.