Fuel Cans - How do they get filled now? Can't figure it out

Hey guys,
With build 277, I can't figure out how to fill an empty Fuel Can and use it for my generator. I've spent a few hours in Creative mode trying to figure it out but even with a filled fuel can, it won't even go in the generator. I thought coalfuel cells and biofuel cells would be worth making to give some extra EU in my CESU.

Are fuel cans worthless now? Or is there some other use I can't figure out.

Thanks.