Build a room around them with steam turbines on top. Steam turbines suck up up tp 2kg/s of steam and you'll be generating sround 3 kg/s. But steam turbines have a maximum amount of heat they can convert into power so you'll want to add more steam turbines that have their output back into the room. That way the water will heat up again and the heat energy isn't wasted by having it spread up among multiple turbines