Steam Furnace Math (from last night) attempt #2
The E-Furnace uses 390 EU per smelting operation (assuming Greg uses standard IC2 machine math)
The Steam Furnace (Bronze, not High-Pressure/Steel) consumes 1024L Steam per smelting operation.
At 100% efficiency, 1 EU = 2.0L Steam
So the Steam Furnace consumes 512 EU worth of Steam per operation (~1.31x the E-Furnace).
Now we take into account Steam Turbine inefficiency.
The LV Steam Turbine is 66% Efficient. At 66% Efficiency, 1 EU = 3.03L Steam.
A LV Steam Turbine consumes 104L Steam/tick to produce 32EU/t (34EU/t, -2EU output inefficiency, 66% efficient
With 0 cable loss (which will only compound the losses), it takes 12.1875 ticks for a Steam Turbine to generate 390EU. In order to output this, it must consume 415 EU.
415 EU x 3.03L Steam/EU = 1258L Steam
So the Steam Furnace is actually more energy efficient than the E-Furnace, if you are using Steam Turbines to generate your electricity.
The difference is that the E-Furnace works 97% faster than the Steam Furnace (130 ticks/process as opposed to 256 ticks/process).
[This is assuming that the GT E-Furnace uses the same energy and time math as the vanilla IC2 E-Furnace, I HAVE NOT TESTED THIS]
It should be noted, however, that the E-Furnace is (before cable loss) 22% more fuel-efficient than the High Pressure Steam Furnace (which consumes 1536 Steam/process).