Redundant solar system to restart the reactor.

[dondada]

First time with nuclear and decided to create a separate grid for the reactor, assembler, centrifuges, inserters, and uranium mines that are all powered by solar in case of emergency. I was hesitant to completely destroy my coal plants and wanted a way to restart everything without needing to handfeed anything.



The main section above is totally separate from the main grid that is powered from the turbines. It can run all night long with the energy stored in the accumulators. Even with the turbines shut down completely uranium ore will still be processed around the clock. The lines on the outer perimeter distribute power across the factory while the lines on the inside are entirely solar.



The mines are powered by the turbines and connected to the main grid, but they are also separately attached to the solar panels. If the reactor shuts down they, and the back up satellite will function during the day.



Wide shot of the entire project.

[Khagan]

I confess that when I saw the title "Redundant solar system" my first thought was of a spare star with a few surplus planets.

[Tertius]

It's nice you realized how important the power supply is, but I would say your approach is a bit overengineered.

What is the reason you built the never failing power supply for your power supply? So the main power supply can never fail. But whatever the reason for such failure is, you need some manual intervention to fix the issue and prevent it from happening again.

You might have to build another power plant if consumption grows above production. Or to fix fuel cell production if fuel cell production fails.

By making your power plant resistant against power failure, you extend the ability to function even under brownout conditions. But this makes your problem worse, because one way or the other, you need manual intervention in the end. And with manual interventions it is best if you do it as soon as possible. Otherwise the problem gets worse before you fix it.

So what you really need to do isn't a power plant power supply safeguard. Instead, you need an early warning system.

Create monitors that fire an alert (with a programmable speaker) if your fuel cell buffer chest is getting empty.
Create a monitor for uranium ore availability, for example check if the belt in front of your centrifuges is empty.
Create a monitor for steam level (if you have steam buffers).
Create a monitor for reactor temperature.
Create a monitor for immediate fuel cell availability for your reactor (monitor the thing that's supplying the inserter that's putting the fuel cells into the reactor).
Monitor general power consumption by wiring one accumulator in the main power grid and send an alert if its charge falls below 100% (in this case the accumulator is discharging, which is a sign your nuclear power plant fails to deliver enough power).

This way you immediately see which kind of issue is happening and you can directly go fixing it.

[dondada]

I haven't played with monitoring systems, or circuit networks, etc., yet. It's on my list of things to do, however I do agree with you. My intent wasn't to create a system that can operate indefinitely, my intent was to create a system that can be restarted easily without manual intervention. I.e., if I leave my computer on all night and come back to a situation where my uranium ore cannot be processed because the line is backed up, then all I need to do is empty the chest and it will kick start back up using solar.

[Tertius]

It's super easy to add some monitor. No combinators required. Just a simple condition in the speaker, usually.

This monitors one of the fuel cell requester chests of my nuclear power plant on Nauvis:

02-18-2026, 20-47-10.png (753.86 KiB) Viewed 262 times

(what you see here in addition, 2 accumulators, is a remains of a power failure safeguard like yours. The reactor infrastructure is on a separate power grid and I squeezed the necessary solar panels and accumulators in. But I never used it - during construction of the power plant I connected it with the main power grid to have enough power during initial reactor heating and while roboports and accumulators were still charging up and forgot to disconnect later. It was never required.)

This one monitors sulfuric acid level on Vulcanus:

02-18-2026, 20-53-17.png (569.53 KiB) Viewed 262 times

You will usually monitor the content of some container or the temperature of some burning device: wire it with a programmable speaker, make sure the container is set to output its content or temperature, and configure the speaker to check for some threshold.

[dondada]

What's Vulcanus? I have Space Age but haven't played it, yet. I wanted to get the vanilla experience first. I'm assuming it's that?

[Tertius]

Vulcanus is one of the planets you will visit in Space Age. To avoid spoilers I will not say more, just the comment that's somewhat important for your power supply to make sure you have always enough sulfuric acid on Vulcanus.

One recommendation, when you finish your current map with the base game, I recommend you start a fresh map with Space Age. Don't load your existing map into Space Age. It's possible, but Space Age changes the tech tree starting with the mid game, and it's a better experience to start from scratch.

[dondada]

Thanks! Quick question so I don't have to make another thread... how do biters work exactly?

Originally I walked all around killing every nest I found. Now they've come back. A moment ago I saw a nest that was within the range of the satellite at my uranium mining camp. Like I could literally stand at the uranium mine and see the nest. I also noticed in my pollution screen that it says something like "Biter Spawner 45."

So I eradicate the nest but I still see that spawner alert in the pollution section, however there are no nests that are extremely close... so which one of the many that are not close is the one that is looking for me?

[Tertius]

There are 2 mechanics connected with biters. The first one is pollution triggering attack groups. If the pollution cloud of your buildings touch some biter nest, this nest and adjacent nests eventually collect a group of biters and the group will go and try to attack the source of the pollution. These are the incoming attack groups you have to fight.

The second one is biter nest expansion. Once in a while, independent from the pollution cloud, some biters will form an expansion group. They will choose some random location a few chunks away not already occupied by nests and walk there. After a short while they will transform into a new group of nests. These are the reason nests that will appear in clean areas. They will also expand back into areas you cleaned before. In case they spawn inside the pollution cloud, they will begin to launch attack groups. And they are of course also a source of new expansion groups.

Details are in the wiki: https://wiki.factorio.com/Enemies#Expansions

If you still see some biter alert and there is nothing on the map if you look, make sure you don't have accidentally pinned the alert. A pinned alert will stick until you dismiss it.

[Nidan]

(This fits better into your other thread, you may want to ask any follow-up questions there.)

how do biters work exactly?

When unprovoked, they occasionally expand by sending out a scouting party that'll build a new nest somewhere.
When you're getting close (~ shooting range), they'll defend themselves, calling for help from other nearby nests when you damage them.
When they're in your pollution cloud, they start consuming that pollution to spawn biters to form attack parties to destroy the source of that pollution. This consumption is what you can see on the pollution screen. To find the nests that are absorbing pollution check your map with the pollution display turned on.

Look for suspicious holes or flickering pollution.

Over time (time passed, nests killed, pollution created) they'll become stronger.
For more details see the wiki.

[dondada]

I got it. So the more of them that I kill the stronger they become? Does that scale linearly? Infinitely?

[Tertius]

About enemies getting stronger: please follow the wiki links and check the info about evolution.

[dondada]

Thanks.

Do you have a link on how nuclear heat loss works? I've noticed if I have more heat exchangers that it seems (maybe I'm wrong) to both take longer for the core to reach maximum temperature and longer for it to drop in temperature. Is that accurate? I would then assume that it doesn't really matter how many exchangers you really have or don't have because the rate at which the temperature drops is equal to the rate at which it increases when it's being fueled and therefore you cannot 'save fuel' by only adding uranium right before it loses the necessary temperature to power the turbines?

[Loewchen]

See https://wiki.factorio.com/Tutorial:Nuclear_power.
You waste fuel if a reactor is at 1000°C while burning it. Heat exchangers create steam from heat, if you don't have enough of them you decrease the maximum output.

[Khagan]

I would then assume that [...] therefore you cannot 'save fuel' by only adding uranium right before it loses the necessary temperature to power the turbines?

If you can insert at the last possible moment, you can indeed save fuel. Timing that moment is not trivial, though it is easier than it used to be. But the first step in fuel saving is to build a four-core reactor to get the neighbour bonus. A single-core reactor is extremely weak and inefficient in comparison.

[Tertius]

I've noticed if I have more heat exchangers that it seems (maybe I'm wrong) to both take longer for the core to reach maximum temperature and longer for it to drop in temperature. Is that accurate? I would then assume that it doesn't really matter how many exchangers you really have or don't have because the rate at which the temperature drops is equal to the rate at which it increases when it's being fueled and therefore you cannot 'save fuel' by only adding uranium right before it loses the necessary temperature to power the turbines?

The heat mechanic is a representation of real world physics. It just lacks the unwanted dissipation of heat into the environment. But energy conversion between fuel, heat, steam and electric power is lossless and conversion is accurate.

So if you burn a fuel cell you get 8 GJ of work. Since a fuel cell burns for 200s, you get 8 GJ / 200 s = 8000 MW/s / 200s = 40 MW power for 200 seconds, which is the amount of heat a single reactor will produce. The neighbor bonus adds more power out of thin air. 40 MW per fully adjacent reactor.

This heating power will heat up the reactor. It has a heat capacity of 10 MJ/°C, so to warm a reactor by 1°C, you need to add 10 MJ. If a reactor is producing 40 MW, it adds 40 MJ per second, so it will heat up by 4°C per second. With neighbor bonus it is more accordingly.

The heat will flow into heat pipes with their own heat capacity and into heat exchangers with their own heat capacity, so the reactor is cooling down (or not heating up so fast) and the periphery will heat up until equilibrium is reached.

If a heat exchanger is at 500°C or above, it will convert water to steam. It's able to convert with a power consumption of 10MW, so heating power extracted from itself is -10MW and heating power added to steam is +10 MW. This is 10 MJ per second. It cools down and steam heats up. Steam is heated from 15°C to 500°C, an increase of 485°C. Heating 1 unit of steam by 1°C requires 200 J. With 10 MJ we get 10 MJ / 200 J = 50000 units of steam being heated up per second, which is 50000/s / 485 = 103.1/s steam being produced.
The steam turbine consumes steam with 60/s. It cools the steam from 500°C back down to 15°C, so again 485°C difference. This is 60/s * 485 * 200 Joule = 5.82 MW.

The important numbers in this calculation are 103/s steam coming out of a heat exchanger and 5.82 MW coming out of a steam turbine, which are the numbers you see in factoriopedia and in the wiki.


What you see if something is taking longer to heat up than some other building is how heat flows through the system. Heat pipes have a capacity of 1 MJ/°C, so this is a limiting factor for heat distribution to take into account and responsible for the heat difference from reactor to distant heat exchangers.

I hope I didn't lose you with the physics calculations, but this is what Factorio is based on. All the odd numbers are not random and not god-given.