To bring a freeze protection heater into a conductive state even if power supply is cut off.
This cogeneration system includes: a power generation part 4 capable of generating power; an exhaust heat recovery means 5 for recovering heat generated in a process of a series of a start, a stop and power generation; the freeze protection heater 6 for increasing the temperature of a water path of the exhaust heat recovery means etc.; and a power source cut-off means 23 for cutting off the supply of a commercial power source. The freeze protection heater 6 has a configuration capable of supplying the commercial power source even if the power source cut-off means 21 is cut off. Since a temperature of piping etc. provided in the same water path as that of the exhaust heat recovery means can be raised by the freeze protection heater even if the power source cut-off means 23 is cut off, the rupture of the piping in the water path at a low temperature can be prevented.
NAGASATO HIROSHI
TODA MASUMI
Daisuke Nagano
Kentaro Fujii