The coal generator (GeneratorConfig class) has a slider, but it's not documented ingame and is confusing people. People assume it's for turning the generator on and off, but in reality it is for turning coal deliveries on and off. The forum (again) had a thread about "why won't dupes deliver coal to my empty coal generator". It's not intuitive that it's because the battery is nearly full. Particularly not if there are multiple batteries and they aren't on the screen at the same time as the generator.
The actual calculations affecting this are in EnergyGenerator.EnergySim200ms.
Another issue is that once the batteries are full, it will continue to burn coal until the coal has been consumed. It might have been a good idea when it was new and the idea was that all the coal was added to the firebox, but now we can turn it off with an automation signal, meaning we know it's not all in the firebox. This makes the coal generator seem very wasteful, particularly because after having been filled with coal, it will run for 600 seconds.
I propose the following fixes:
- Add proper text to tell that it's an on/off for coal deliveries
- Add a slider for how much coal to store
This will make it easier to understand, less wasteful and actually useful while at the same time it's handicapped enough to ensure that it's not a replacement for controlling with automation wires.
One important thing to remember about the coal generator is that it's likely the first fueled generator new players will encounter. That just makes it worse that it's the most confusing generator to use.
UPDATE: mod implementing the proposed solution:
EDIT: another issue came up. The coal generator is apparently stuck if there is no battery (I didn't test, just relaying the following post). That's something else the new player can get confused about.
Steps to Reproduce
Build a coal generator. Try to control it with the slider.
This issue has not been confirmed by a developer yet.