A laser system includes a plurality of diode lasers, a cryogenic cooling system circulating a cryogenic coolant and coupled to the plurality diode lasers to cool the plurality of diode lasers with the cryogenic coolant, and a fuel cell coupled to the plurality of diode lasers to power the plurality of diode lasers and situated to receive the cryogenic coolant from the cryogenic cooling system as fuel for the fuel cell. A method of operating a high power laser system includes cooling a plurality of diode lasers with a cryogenic cooling system circulating a cryogenic coolant, fueling a fuel cell with a portion of the cryogenic coolant circulating in the cryogenic cooling system, and powering the plurality of diode lasers with power generated by the fuel cell.