However, the news report may have a slight typo in describing the power that was reached:
Researchers at the Department of Energy's nuclear physics laboratory on Friday injected a record-breaking 500 kilovolts of power into the laser's accelerator. The previous limit set by Jefferson Lab researchers had been 320 kilowatts.
They may have meant 500 kilowatts of power. Kilovolts is potential difference, and it is also not kosher to compare kilovolts with kilowatts.
In any case, this is quite a significant increase! One would hope that the US Navy knows where to point one of these things if they ever build it on their ships.
BTW, in case people don't realize it, a free-electron laser (FEL) is an ACCELERATOR facility (i.e. it is not an optical/solid state light source). I'm simply highlighting another application/use of accelerator physics.