A distributed power generation system for being installed in combination with a solar cell, comprising: a distributed power generator configured to perform power generation by using a fuel supplied thereto to generate electric power and heat, and supply the electric power and the heat to an electrical load and a heat load; and a controller configured to create an operation plan of the distributed power generator, and control at least start-up and stop of the distributed power generator, wherein the controller is configured to receive load data of at least one of the electrical load and the heat load, and the controller is further configured to execute a first operation mode including the step of controlling the distributed power generator based on the operation plan; and the distributed power generator includes: a power generation unit configured to perform joint supplying of the electric power and the heat; and a heat accumulator configured to store the heat supplied from the power generation unit, characterized in that the operation plan specifies, when to cause the distributed power generator to perform power generation and when to stop the distributed power generator; the first operation mode further includes the steps of setting at least one of a start-up time and a stop time of the distributed power generator to create the operation plan, by setting a priority period based on a sunrise time and a sunset time, such that the operation plan includes, at least partly, the priority period, and determining based on at least the load data whether to cause the distributed power generator to perform power generation in the other periods different from the priority period; and the controller is further configured to correct and reduce the priority period gradually in an iterative procedure, based on a comparison of a sum of the heat supplied by the distributed power generator when the distributed power generator performs power generation in the priority period and a heat amount stored in the heat accumulator with a heat amount used in the priority period, the heat amount being predicted from the load data of the heat load, the load data being received by the controller. a distributed power generator configured to perform power generation by using a fuel supplied thereto to generate electric power and heat, and supply the electric power and the heat to an electrical load and a heat load; and a controller configured to create an operation plan of the distributed power generator, and control at least start-up and stop of the distributed power generator, wherein the controller is configured to receive load data of at least one of the electrical load and the heat load, and the controller is further configured to execute a first operation mode including the step of controlling the distributed power generator based on the operation plan; and a power generation unit configured to perform joint supplying of the electric power and the heat; and a heat accumulator configured to store the heat supplied from the power generation unit, characterized in that the operation plan specifies, when to cause the distributed power generator to perform power generation and when to stop the distributed power generator; the first operation mode further includes the steps of setting at least one of a start-up time and a stop time of the distributed power generator to create the operation plan, by setting a priority period based on a sunrise time and a sunset time, such that the operation plan includes, at least partly, the priority period, and determining based on at least the load data whether to cause the distributed power generator to perform power generation in the other periods different from the priority period; and the controller is further configured to correct and reduce the priority period gradually in an iterative procedure, based on a comparison of a sum of the heat supplied by the distributed power generator when the distributed power generator performs power generation in the priority period and a heat amount stored in the heat accumulator with a heat amount used in the priority period, the heat amount being predicted from the load data of the heat load, the load data being received by the controller.