Indeed, in the laser business, during a time period when it seemed like someone was coming up with a new kind of laser every month, the field developed a term,

Indeed, in the laser business, during a time period when it seemed like someone was coming up with a new kind of laser every month, the field developed a term, "wall plug efficiency," which meant how much laser power per unit of power drawn from the electrical outlet. It was meant to capture the true energy efficiency of the system, rather than just the efficiency of the lasing process.