D-D reactor requires 250EC/s to start, generates 400EC after.
Produces Helium-3 in the reaction process and tricium to spice up the reaction.
Rest of the energy goes to helium production via particle accelerator:

Fusion: deuterium imput is twice the helium 3
particle accel: same imput of deuterium and hydrogen, yielding same amount of deuterium
unit wise.

so ratios looks like this:

D - 4
H - 3

-->   3He - 3.5
