1. An energy management apparatus comprising: a power generation estimation unit configured to estimate a power generation amount of a power generation apparatus using a renewable energy; a demand estimation unit configured to estimate an energy demand of an electrical device of a customer; a creation unit configured to create an operation schedule of the electrical device based on the estimated power generation amount and energy demand; and a controller configured to control the electrical device based on the operation schedule, wherein the demand estimation unit comprises: a storage unit configured to accumulate load data representing a result of a load of the electrical device; an extraction unit configured to extract a plurality of load patterns including a plurality of different load data from the accumulated load data; and a calculation unit configured to calculate a weight based on a predetermined standard for each of the extracted load patterns, and the creation unit comprises: a simulator configured to simulate, using a predetermined algorithm, an evaluated value of each operation schedule based on the extracted load pattern and the weight of the load pattern; and a schedule creation unit configured to create the operation schedule based on the evaluated value.