ENERGY CONTROL SYSTEM, ENERGY CONTROL DEVICE, AND ENERGY CONTROL METHOD

An energy control system (1) includes a photovoltaic power generation unit (10) that is connected to the grid and generates power using sunlight, a gas power generation unit (20) that generates power using gas, and a control unit (40) that performs control to supply a load by prioritizing the power generated by the gas power generation unit (20) when sale of the power generated by the photovoltaic power generation unit (10) to the grid is possible and to supply the load by prioritizing the power generated by the photovoltaic power generation unit (10) when the sale is not possible.