Not tested it yet but I see a lot of MFR power supplies on the server I'm on. Mostly Harvesters on trees, and if that's a positive energy loop (via charcoal, biofuel, ethanol, and/or boilers) then that has got to be the easiest to get going. Personally I've fallen back on coal coke and hobbyists for the initial pulverizing, but the Dartcraft engine looks quite OP and MFR looks quite straightforward to setup. Maybe LP/HP boilers won't even be necessary?