Guys, seriously this has been a bug for THREE YEARS. Now I'm running out of Natural Gas, Coal was my back up plan and now that doesn't work either, so my base in in danger of dying. I literally have tons of coal sitting RIGHT NEXT to my coal generators at priority 9, slider at 100% and my dupes are completely ignoring them. I also tried dismantling all but 2 of them. Dupes will build them, dismantle them, disable them and enable them but they won't *#^%^ fill them with coal. I don't understand why they work fine in early game but once you get to about 20+ dupes they start to break.