They spend 60 seconds charging 400 megajoules of capacitors, then they discharge them in a half-millisecond pulse. The peak electrical power is one terawatt. The laser compresses this pulse further, so that the light pulse is only 3 nanoseconds long, but with a peak optical power of 500 terawatts.

https://lasers.llnl.gov/about/nif/how_nif_works/power_condit...

https://www.llnl.gov/news/newsreleases/2012/Jul/NR-12-07-01....