Factorio Forums

Posting after having a discussion on reddit.
https://www.reddit.com/r/factorio/comme ... y_nuclear/
I was expanding a 'grid' of Substations and robo ports. I let Factorio run and was away when the issues started.
When I returned, all structures that require power, except laser turrets and silos, are no longer powered. Those structures are showing without power, and electric network info shows consumption at 0W
They are connected to the power network.
Nuclear power is generating power in excess, it's as if the buildings themselves aren't 'requesting' the power.
After discussion on reddit, I tried some things to figure it out. I'll just copy & paste the process here.

I've done some testing based on your comments and here are the results, consider this a log of the process:

Isolate nuclear power: Power Distribution Bug (PDB) fixed!
Reconnect to factory: PDB active
Disconnect all the laser turrets: PDB active
Remove silos: PDB active
Disconnect half of the 'grid': PDB active
Disconnect another half of the remaining grid, including majority of factory: PDB active
Disconnect another half of the reamaining grid: PDB active
Disconnect another half of the remaining grid: PDB fixed!
Undo previous step: PDB active
Disconnect section of grid and isolated that was consistent with PDB bug, but reconnected the entire rest of the factory+grid: PDB active
Connected about 50% of the factory without PDB active, through process of elimination isolated issue to two possible roboports. Removed and replaced a single roboport: PDB fixed!!!
Deleted and replaced ALL power polls/substations and roboports in the entire factory: PDB fixed!
So, it looks like at least two items were bugged in some way that 'corrupted' the algorithm for power distribution, at least that's my best guess.

PDB active = power distribution isn't functioning as intended, and only laser turrets are silos are receiving any amount of power
PDB fixed = power distribution is working as intended.
No mods were installed during the creation or playtime of this specific save. Vanilla Space Age.
The save file included is currently in the PDB state before I started to diagnose the issue. If there's anything else I can add to help, let me know!

The issue seems to be connected to the power network, not nuclear power plant.

-adding other power source (10MW of solar power) did not change anything.
-added accumulators are charged (even without solar panels) but also do not provide power for buildings.

-Most buildings (existing and newly placed) shows red "low power" warning (so, they are seeing they are in a grid with some power) and have 0 power in the internal storage. But not all. Primary consumers like laser turrets, tesla turrets and railguns are powered! (BTW, combinators also sems to be powered, but they just start with a bit of power, so the warning is not triggered).

Your save file has 3 roboports with an invalid amount of energy stored in them. Invalid in the many many orders of magnitude wrong. The roboports have 18446744000000000000 times too much energy compared to what they should have. This is causing some computations that assume energy <= buffer size to report the roboport as always lacking a massive amount of energy. Since this is *never* supposed to happen and as far as I can find all code paths are correct in preventing it - this indicates to me that the memory on these roboports energy source was corrupt some how - either in memory through bit flips, or on the CPU while it was calculating with them.

The roboports are:

roboport at {182.000, -212.000}
roboport at {182.000, 544.000}
roboport at {254.000, -464.000}

You can "solve" this by holding CTRL while loading the save file - which will force clamp the entity energy values to their buffer sizes as if you added or removed a mod.

However, if they got corrupt like this - without finding the underlying reason - they're likely to get broken again in the future.

Well that's certainly enlightening, and concerning for me. Thanks for taking the time to explain! Might be running some memtest in the near future. lol...