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Re: Accumulator / Solar panel ratio
Posted: Wed Aug 19, 2020 2:50 pm
by ickputzdirwech
astroshak wrote: Wed Aug 19, 2020 2:44 am
Then you have to find a common point - how many reactors in a 2xN setup produce the same MW as a given number of Boilers+2 Steam Engines, and how many Solar Panels/Accumulators provide that much power?
[... everything in between ...]
It is very expensive compared to boilers.
Koub wrote: Mon Aug 17, 2020 3:38 pm
[Koub] this is drifting to off topic. The thread is about solar to accumulator ratio, not the power to ressource ratio of solar vs other power generation.
You might be looking for this thread, where such things have already been discussed.
I think this is exactly what Koub meant. This topic isn't about comparing solar power to other means of power production but only about the ratio between solar panels and accumulators.
mrvn wrote: Tue Aug 11, 2020 3:22 pm
If you use more solar cells then they will provide more power earlier in the day and last longer in the evening. That means less power will be drawn from the accumulators over night and you can use less of them. They will also be recharged faster during the day and then there will be excess power that will simply go to waste (assuming our constant consumption of power). But to some accumulators are expensive and solar cells are cheap. Space is also often not a problem or you probably wouldn't be using solar. So wouldn't a 30:18 (or whatever ratio makes it work again) be better if you assign accumulators a higher price than solar cells?
So what we really should have is a table with solar cells at one axis and accumulators at the other axis and the garanteed constant power as values in each cell. There would be a region in the table with sensible combinations of solar cells and accumulators. But also regions that don't make sense. Any cell that doesn't improve on the one with one less accumulator is out too. That's just wasted. On the other side though, asides from having 0 accumulators there is nothing to obviously exclude. Every added solar cell will increase the power even one accumulator will alow as constant draw. But it quickly becomes near 0.
There would be a line starting at 1,1 and go through 25:21 that reflects the "optimal" 0.84 ratio. The line of maximum accumulators. How many additional W/solar cell does that line give? I think it's something around 40W/cell.
The question I would want answered is: Given a cost ration X:Y for solar cells to accumulators what ratio gives you the most W per cost and how much is it?
This is a really interesting thought! The math would be quite complicated. Therefore I'll elaborate it with logic only:
The ratio 100 solar panels to 84 accumulators is
optimized for solar panels first, than for accumulators. We could do that the other way around. We would need the fewest accumulators if we would just draw power from them if solar panels would produce no power at all. For that we would need an infinite amount of solar panels however, since the power output of each solar panel is just tiny at the end of dawn and the beginning of dusk. That this would be worse than 100:84 is obvious but we don't have to go that far.
Would it make any sense at all to reduce the number of accumulators in favour of more solar panels? No! Because of the following reasons:
Minimizing the amount of solar panels first is therefore definitely the way to got. The 100 solar panels to 84 accumulators ratio is the best way to go as long as you have relatively constant power consumption and you don't want to build more than you really need.
Re: Accumulator / Solar panel ratio
Posted: Mon Aug 24, 2020 12:16 pm
by mrvn
You assume you are playing vanilla. And even there oil might be rare and you might need every drop for something else while having lots of iron/copper deposits.
And speaking of modded the specs for solar pannels and accumulators can change. So some spreadsheet magic would be needed so people just have to plug in the values for solar pannels and accumulators to refresh the table. Might be nice to have a few presets for Angles and Bobs mobs or other common sets. Anyone up for it?
Re: Accumulator / Solar panel ratio
Posted: Tue Aug 25, 2020 7:11 am
by Hannu
ickputzdirwech wrote: Wed Aug 19, 2020 2:50 pm
Would it make any sense at all to reduce the number of accumulators in favour of more solar panels? No! Because of the following reasons:
- Space: Solar panels use more than twice the amount of space than accumulators. There is no way we will save more than two accumulators with each additional solar panel.
- Material: Accumulators are way cheaper than solar panels. Even if you consider 10 Oil being worth 1 copper or iron ore (personally I consider oil free like water since it is infinite)
It you think oil is very precious, it can be advantageous. Then you can for example switch electric smelting off if battery charge is under some limit. I do not see it good idea at vanilla game at most settings, but there may be mods, extreme settings or personal preferences which change the situation.
That 25:21 is calculated with the most trivial conditions. If you want to take more complex conditions into account it will be very much more complex mathematical problem. Solving such problems is more math hobby that gaming hobby. Such solution is valid for that specific game and can not be generalized
(without suitable proofs).
Re: Accumulator / Solar panel ratio
Posted: Tue Aug 25, 2020 7:16 am
by Hannu
mrvn wrote: Mon Aug 24, 2020 12:16 pm
And speaking of modded the specs for solar pannels and accumulators can change.
If mod does not change the diurnal cycle, you can calculate optimal ratio by:
(25 * P_vanilla / P_modded) / (21 * C_vanilla / C_modded),
in which P is power of solar panel and C is capacity of accumulator.
Maximum charge or discharge power of accumulator may need to be taken into account in some situations.
Re: Accumulator / Solar panel ratio
Posted: Fri Apr 22, 2022 1:22 pm
by Bilka
Someone made an edit on the solar panel wiki page, changing
It takes 23.8 solar panels to operate 1 MW of factory '''and''' charge 20 accumulators to sustain that 1 MW through the night.
to 25 accumulators. The accumulator page links to this thread to explain the 20 accumulators (instead of 25), citing accumulators not immediately discharging at the start of dusk. I decided to verify the calculations here with the game.
Attached is a savegame with 24 solar panels, 20 empty accumulators and 1000 combinators (full buffers, totaling to 1MW consumption) paused at daytime 0.7 (somewhere during dawn). Letting it run for 25000 ticks (day length) with the editor shows that at the start, the solar panels already provide enough power for the combinators, so accus start to charge. This charge is enough to last through the night, only getting as low as 460MJ. So, 20 accumulators are enough to last through the night with ~24 solar panels and 1MW of production, as previously stated on the wiki.
This is just repeating math that has been discussed several times in this thread, but I like verifying things before reverting wiki edits :)
Re: Accumulator / Solar panel ratio
Posted: Fri Apr 22, 2022 4:43 pm
by Qon
Bilka wrote: Fri Apr 22, 2022 1:22 pm
but I like verifying things before reverting wiki edits
I'm an admin over at
https://wiki.factorio.com. Feel free to contact me if there's anything wrong (or right) with it.
Bilka, YOU are what's right with the wiki <3
Re: Accumulator / Solar panel ratio
Posted: Sun Apr 24, 2022 3:19 pm
by Pascali
So with 24 Solarpanels + 21 accumulators i have enough energy for 1 megawatt fabric for day and night?
Re: Accumulator / Solar panel ratio
Posted: Mon Apr 25, 2022 8:23 am
by Koub
Pascali wrote: Sun Apr 24, 2022 3:19 pm
So with 24 Solarpanels + 21 accumulators i have enough energy for 1 megawatt fabric for day and night?
Yes.
Re: Accumulator / Solar panel ratio
Posted: Tue Apr 26, 2022 12:25 pm
by Pascali
Thank you Koub!
Re: Accumulator / Solar panel ratio
Posted: Wed Jan 01, 2025 6:43 pm
by Jetboy
Thanks to Cilya for the great post. I have come by it more than once, and ended up reading it multiple times, as it is very well-written and rich of useful information.
That said, I think there is a small computation error by the end of your explanation:
Cilya wrote: Fri Aug 29, 2014 2:03 pm
Times are in fraction of day, so they must be multiplied by (25 000 / 60).
A full in-game day is 7 minutes, which equal to 420 seconds. 420 seconds * 60 ticks per seconds = 25200 != 25000.
This sadly shifts the accumulator to solar panel perfect ratio from 0.84 (21 accumulators to 25 solar panels) to 0.84672 (2626 accumulators to 3125 solar panels).
Re: Accumulator / Solar panel ratio
Posted: Wed Jan 01, 2025 6:49 pm
by DaveMcW
Yes, the 25200 tick day was added in Factorio 2.0.
Re: Accumulator / Solar panel ratio
Posted: Thu Jan 02, 2025 2:21 pm
by jockeril
but isn't the easiest solution just to have more accumulators ? and anyway, you get to nuclear so fast that you might as well skip solar all together for the most part on Nauvis. it might prove more useful on Volcanus so I wouldn't not research it, but I think that's just about it,
(I'm no mathematician, I have dyscalculia and am unable to actually make those kind of calculations without consulting an AI, which might not be a bad idea, but I will not
)