They don\'t need to be in a line, they just need to always be expanding in one direction (x, y, or z).
So a line | of 40 blocks gives the same power as a L of 40, as a T of 40, or a + of 40, or a 3d + (plus with some coming out from all directions)
The best way to do power is just have the power \"lines\" go along with the shape of your ship, and then have multiple \"lines\" until you get the power you need. Its an exponential gain the more you have for each \"line\"
You can do reactors, but they give very little power PER block, so you are wasting mass.