Basically it works like a steam engine in terms of energy confinement. Look Ma! No expensive magnets. The electric bill might still be a problem. The lasers uses micro compression to provide the heat, The Boron Hydrogen fuel burns in such a way that the "flame" stays within the body of the flame. The energy output is helium atoms without electrons, which is a simple positive electrical charge, that is collected outside of the reaction. The lasers are extremely powerful but the ultra short pulses keep everything manageable. It certainly looks very practical.
Tempting to think If the energy coming out of it was stored up for a while and then it was fed back from that pool of energy to the unit's lasers and support machinery, and some of the output electrical energy that was fed back to that pool of energy, would it run for years on a single dose of boron? Assuming hydrogen could be picked out of the air or does it require massive amounts of fuel? I didn't see how much fuel it used. Maybe it needs a lot of boron and hydrogen as it is just using helium atoms without their electrons as the generated electrical power. How powerful could helium ions be?