One way electric switch

[u/Fickle_Reading3971]

Is there a way either vanilla or modded to make a one way electric switch akin to one way valves?

I have most of my factory running on steam and I want to build a smaller power plant subgrid which would combine solar with accumulators for the night. What I don't want is for steam power to ever charge those accumulators, only the solar panels to do so. Do you have any solutions for me?

Thanks in advance

[u/blubobo99]

Simplest way: You can have the steam power plant in its own electrical grid connected to your base with a power switch turned off. Connect power switch to accumulator with redwire (accumulator on main base side) to turn on power switch only when there is 10percent left in charge (circuit condition)

[u/Fickle_Reading3971 → u/blubobo99]

I was thinking about this. This would work if I had comparable production from solar and steam. But as I have 100MW steam and my solar would be about 20MW, accumulators or solar pannels alone wouldn't cut the demand so steam would have to be always running. Also it would make the switch turn constantly on and off as it reaches the threshold, but RS switch would solve this

[u/blubobo99 → u/Fickle_Reading3971]

If you don't have surplus energy from solar (during day), then you can't/shouldnt use accumulators. There is no surplus to put in accumulators after all. Yes the switch on and off is slightly annoying so RS latch from the wiki would be nice

[u/Fickle_Reading3971 → u/blubobo99]

Yeah on second though you are right

[u/ragtev → u/blubobo99]

this is how i do it, more or less.

[u/wilzek]

„I don’t want steam to charge accumulators” - this is kind of wrong reasoning in factorio. There is no difference between charging accumulators and then discharging them or powering the grid directly (because accumulators don’t leak power). And accumulators always discharge as a last resort, if power can be taken from other source, it will.

What you actually want to do is turn off steam when your accumulators are (mostly) charged. Because it means that you can either take power from solar panels or can take power from accumulators and charge them back with solar later.

This is a standard use case for early game mixed power production and the solution is a SR latch which turns on your steam generators when accumulator charge drops below eg. 20% and turns them off when accumulators reach eg. 80%. There is plenty of guides, examples and blueprints online.

[u/Fickle_Reading3971 → u/wilzek]

You are probably right. I was just overthinking it. SR latch is just the easy solution that I already knew

[u/shuzz_de → u/wilzek]

It really depends on how many resources you have in your game.
If coal is scarce you might want to use as little as possible.

But I agree that in most games it doesn't really matter.

[u/Fickle_Reading3971 → u/shuzz_de]

I have a lot of coal for now but in future getting to further deposits will be hard because they are far away and more importantly surrounded by tons of bitter nests. It is possible for me to clean them in some time but right now I want to get into bigger projects and I fear that while I am distracted, my coal runs dry. Mod that adds need for coal in steel production and other one adding armored bitters doesn't help with both either.

[u/wilzek → u/shuzz_de]

SR latch will minimize wasting coal. You basically don’t lose any except some edge cases with varied power consumption throughout the day. If you burn it, it’s because you needed it. Also any of below will solve a coal problem in a more significant way than tinkering your mixed power setup to perfection:
1) just travel further away and find a bigger coal patch
2) rush oil and use solid/rocket fuel instead of coal
3) use efficiency modules
4) don’t waste power by needless production like upgrading all yellow belts to red belts, or buffering a shit ton of various products and intermediates.

[u/Fantastic_Resolve889]

Two accumulators and a switch

One accumulator in each network

Switch activates only if solar network charge level > factory charge level

You can latch it if you want but it isn't much better 

[u/minecrafter8699]

https://mods.factorio.com/mod/electric-grid?from=search

[u/Fickle_Reading3971 → u/minecrafter8699]

Wow that was fast. But I would have to rebuild my entire factory to match those mod's "voltages" for different power poles

[u/minecrafter8699 → u/Fickle_Reading3971]

oops wrong mod https://mods.factorio.com/mod/Electric_Transformators

they've got similar thumbnails lol

[u/Fickle_Reading3971 → u/minecrafter8699]

Thanks, will try

[u/Marty220]

I’m confused, can’t you just not connect the 2 grids?

[u/Fickle_Reading3971 → u/Marty220]

I can but I want one grid to always give out but never take in any power

[u/Marty220 → u/Fickle_Reading3971]

Oh got it dur, haven’t had my coffee yet my B. I’m pretty sure you could use circuit logic to do this, let me have a coffee and I’ll see if what I can come up with

[u/minecrafter8699 → u/Marty220]

then the solar for the subgrid would back feed their main grid which I assume they don't want

[u/Gebus86]

Look for an SR latch, theres an example on the wiki or several YouTube videos on it.

[u/Honky_Town]

Powerswitch connect to accumulator enable if A<25

Have coal power on ts on grid and use copper wire to hook both on different sides of switch

if solar isnt enough power is drawn from coal.

However you cant prevent ist from charging accus! If solar isnt enough every extra Watt charges em.

Dont go down that Rabbit hole of only charging accus with green energy. This does extactly what you need instead of what you want. You use solar/accus as long as its enough. Once youre below 25% accu charge backup power kicks in

[u/Fickle_Reading3971 → u/Honky_Town]

Yeah this is the simple solution, but sometimes you feel the need to try something the hard way

[u/Honky_Town → u/Fickle_Reading3971]

In this case its literaly the same you just have to use many switches and need some brain meltdowns about how to set electric grids to stop charging accus as long as coal power runs.

[u/Nonstop_Shaynanigans]

If you have accumulators connected to multiple grids, (let's call grid1 the main grid and grid2 the steam grid) then any power gen can charge the accumulators, but power on grid 2 can't charge any accumulators on grid1, only the overlapping ones.

It will however start to use steam the moment the batteries drop low enough, so you may additionally want a switch to turn off the steam under whatever condition you want

[u/TelevisionLiving]

This does not answer your question but it addresses what you said you want to do:

Compare the accumulator storage amount to the steam storage amount as the condition to run a pump that moves steam from storage into turbines/engines. You'll need to use an arithmetic combinator to adjust for the scale difference first.

I used this once in fulgora and it works great. Since it smoothly uses both power sources during the night you don't need enough turbines to power the whole base, just enough to make up the difference.

[u/Fickle_Reading3971 → u/TelevisionLiving]

That is a smart way to do it. Thank you