Such generators are possible but we would have to be careful not to trivialise existing mechanics. In TA every possible unit was added and I think we still have the same mindset so if a model was made it would probably be included. It is then up to efficiency balancing to keep static fusions useful.
Also I'm unsure if it could be connected to the power grid. The current implementation of graph modification is lazy and probably insufficiently fast. This would have to be improved or the inability to Overdrive could be a balancing factor (and consistent with other mobile sources of energy).
"From what i recall is that everything a com does can also be done by a unit."
Comm base metal and energy production is an exception. Some income smooths the start of the game and the income cannot go anywhere else. I don't want 'disembodied income' that is tied directly to the existence of a player.