This was the data that Roland had calculated repeatedly. To penetrate the "Sigh Wall" and hit Dejir's "core," at least this much energy would be needed. If it fell below this value, you could enjoy watching your positron beams get deflected and, amidst your laments of "We failed to penetrate the enemy's armor!" be annihilated by the retaliatory particle beam, leaving nothing behind.
Calculating the result was merely the first step of an arduous journey. Where to find such a vast amount of electricity, and how to transmit it to the positron sniper rifle paired with the Unicorn, was the truly headache-inducing issue.