2800W total... BFL does 5 GH/s for about 30W, so 1000 GH/s would require 6kW. That leaves -4.2kW to condense enough nitrogen to cool it. Checks out!
Everyone knows thats how you cool things, put the energy being saved backwards through a heating element and then the liquid nitrogen, being so low temperature, turns the main ASIC into a superconductor negating loads of power draw. That's how it's really done.