Not that I'm any expert, but given that these giant lasers are the definition of niche products I imagine they're also the least optimized. From some quick goo

Not that I'm any expert, but given that these giant lasers are the definition of niche products I imagine they're also the least optimized. From some quick googling, apparently the overall efficiency of a steam power station is around 29% (https://www.eeeguide.com/steam-turbine-efficiency/ https://www.eeeguide.com/steam-turbine-efficiency/), measured by heat-in vs heat-equivalent-electricity-out. So once we get past the laser inefficiencies, we get 29% of net power. From my completely lay-person understanding, the "hard part" was getting more energy out of the reaction than was put in. Now it's an optimization problem, unless there's a hard constraint on the design of these lasers that can't be improved beyond a certain point