Realising (too late) that the carbon rotors I was using for my high voltage windmills wont work with my new shiny extreme voltage one.
I set my mass fab running to finish off making the iridium for my iridium rotor while i shinned up the ladder to where my windmills are, took 'em all down and opened my crafting thingummy to combine them. Only after placing my new state-of-the-art EV windmill do I find out the rotor wont go in.
No problem, I think, i'll just head down and make an alloy rotor, i'm sure those work.
Bzzzt, nope. By the time I get back down my MSFU has been totally drained and I can't even get into the ME network to get stuff out. And that includes my buckets, so I'm forced to head into the quarry and dig out some iron and coal and enough cobble for a vanilla furnace so i can make some buckets to pick up some lava for my backup geothermal generators.
DERP.
Always have a backup genny and fuel in a off-the-grid chest when using AE. Oh the amount of times my base has ground to a halt due to power outs ...