Power generation apparatus and the cogeneration system

Power generator 1A includes a combustor 11, a heater 13, and a Rankine cycle circuit 20. The combustor 11 is burning a solid fuel. Combustion gas generated in the combustor 11 passes through the flue 12. Heater 13 includes a heat storage material, and the combustion gas flue 12 heat storage material to heat the heat storage material by heat exchange. Rankine cycle circuit 20 includes an evaporator 21 for the working fluid of the heated heat storage material and the Rankine cycle heater 13 to evaporate the working fluid by heat exchange. This implements a stable operation of the power generator using the combustion gas of the solid fuel.