"The main problem is, with no ambient source of tech to draw upon, the ship needs to both produce the tech itself, and perform the complex conversion to meld the two together. It also has a magic generator, for when it enters null-magic areas, though it has difficulty providing power to both at once, indefinitely. Thankfully, they have extremely efficient energy sources, and can power these generators, from small crystals they produce, but the strain on the crystals is too much, if both are active at once, for extended periods. But, yes, we could store the 'stable' energy in packs that small, for a similar purpose. They just simply couldn't produce their own recharges."<br/><br/>"I actually asked the same question, the first time I saw it. Apparently, in the deep span between our worlds, there are powerful winds, that, when aligned carefully along the ship, can actually allow it to travel without using any energy for a time, which they state is efficient enough to justify it, over the symmetry and aerodynamics."