2 HV Hatches = 1024V = EV = overclocked = 1920EU/t for tungstensteel...
You need 1 HV hatch, and a 2 amp supply.
This. Don't use more than one hatch, it's not necessary. And in fact it penalizes you. Overclocking the EBF processes dusts twice as fast, but it uses 4 times the EU (or something like that). By using 2 hatches of HV you overclocked and quadrupled the energy required.
Here's my setup: 16 LV Turbines in groups of 4, each group's output goes into a GT LV Transformer that I hit with a rubber hammer to invert it so it outputs 1 amp of MV. I then run those 4 Transformer outputs into a GT MV Transformer, again inverted, and I get 1 amp of HV as my output. I run this into a HV Battery Buffer Box with TWO Lithium HV Batteries in it, and I butt that Buffer right up to the HV Energy Hatch on my EBF.
Since Energy Hatches accept 2 amps, the 2 HV Batteries ensures that the EBF will always have power and won't ever fail. However... since I'm only inputting one amp into the two-amp (two-battery) buffer box, the batteries run down slowly as the ingots cook up in the EBF. So I can only do 4 dusts at a time, then I have to let the batteries recharge. I could increase this time by adding more batteries, as many as I could make or fit, theoretically. But practically speaking, 2 Lithiums is 3,200,000 EU stored up so that will get you thru at least a couple of Tungstens or Tungstensteels. As I like to say... "you gotta babysit the big dummy".
FYI Overclocking is best explained by this page:
http://ftb.gamepedia.com/GregTech_5/Electricity
"If a recipe has a minimum required voltage within a lower tier than that of the machine, the recipe is overclocked. Overclocked recipes are carried out at double normal speed, double normal total energy, and thus quadruple normal energy per tick."
Ideally you'll either have two EBF's, one for MV recipes and one for HV, or else the capability to switch between two power supplys/hatches. But practically speaking, I'm ignoring all that and just running an HV power supply/energy hatch. I pay the penalty to overclock all the MV recipes, but my CreoTek CreoStak 36 means I never really have to worry too much about steam, because its basically free. If I use some extra EU, oh well - I got my stuff twice as fast.