Factorio Forums

Hello.

Is there a way how to modify power production priority? Could this be done via mod?

It can be done with a mod, yes.
May or may not be possible with an in-game command script.
Can't be done in the normal course of play.
Simple swapping of the priority of steam and accumulators doesn't result in a better situation, because the steam engines just turn on as soon as the accumulator charge starts to drop.

Might I suggest building air gap networks for depleting your accumulators first? (Assuming this is the problem you're looking to solve.)

Yes, the goal is to drain accumulators first.

Why would steam engines started before accumulators were empty if they had lesser priority?

What is air gap?

I split the power grid into main (with solars) and backup (with steams). Then I added accumulators to the steams just enough to deliver their power output. I connected those accus to the main power grid. Because main power grid has 10x more accus, the steam engines run at 1/10 of main grid power consumption. It's not perfect, but at least something.

Because they'll attempt to refill the charge the accumulators lose.
It takes more than a simple priority change to get them to fully drain before activating.

An air gap, in this context, is using accumulators to bridge between your main power network, and your steam engine backups.
With the fact that accus won't recharge other accus, you have a setup where your steam engines only charge the power used by the items in the steam engine network, except when the main network runs low on solar, then the steam power starts recharging a small portion to the overall accumulator drain, then when all the other accus in your main network are empty, the ones bridging your steam and solar networks output at full power and your steam engines provide all the power.

Basically, if you never run out of accumulator charge in the main network, your steam engines never use more power than the percentage of total accumulators you have.
If you do, then they provide as much power as they need to.

Just remember that when building these transfer points, that each accum will only transfer 300kW at a time.
I find using two overlapping substations to be the most space-efficient design.

There are pictures of the various layouts, but they're not under obvious search terms unfortunately. Just spent 10 minutes going through the forum.