One of the things I've learned in the past couple of days is how invaluable certain non-tac BOff and Captain skills can be to DPS generation when using beams.
I've done some research and what seems to be the case is that boosting your weapon energy over 125 has the benefit of lowering the overall weapons energy drain from each firing cycle. A volley of six beams drains 50 power. If you're over 125, then each extra point means you get to ignore one point of energy drain per volley. If you're firing 6 beams with a weapon power level of 150, then it will only drain 25, meaning every beam that cycle is hitting for maximum damage. After the cycle is over, the energy level bumps back up to 150 and you can fire another maximum-damage salvo.
This is why engi captains and BOffs can boost a beam-boat's damage output considerably. BOffs get the Auxillary Power to Weapons skill, which provides a nice boost to weapon power. They also get EPS Power Transfer, which can boost a ship's power settings by a good chunk. For short periods of time, even an 8 beam cruiser can fire all weapons for maximum damage.
Engi captains also get the Nadion Inversion power which reduces weapons power drain from firing (among other benefits). It's only doable once per 3 minutes.
Additionally, the Omega Adapted Tech set has a chance on-hit to boost your resistance to weapons power system drain by a considerable amount (along with other benefits). It doesn't last long and has a low (2.5%) chance of firing off when your ship is struck by an energy weapon.
TL;DR version: If you're going to pack 8 beams, be an engineer, set your power level to 100 and learn how to cycle your APtE, NI, and EPSPT skills to ensure maximum damage output from all 8 banks.
this is the key to the 9k dps assault cruiser build
he has 3 of the doffs that reduce cooldowns on boff abilities by 10% when aux to batt is activated. he has one that reduces weapon drain by 500% for 8s when directed energy modulation is activated.
by having 2x aux to batt, you can cycle boff abilities like a madman. 10s or less fire at will cooldown? yes please. 30-40s cd on directed energy modulation? yes please. cycle it with nadion inversion and other engineer abilities and you can keep your weapon power at or above 100 for extended periods which is a substantial dps boost.