Energy management system, independent system, and operation method of independent system

An independent system including a renewable energy power generator, a storage battery, a control device including an energy management system, and a load, wherein

• the energy management system comprises:
• a calculation part configured to calculate a prediction value of charged/discharged power of the storage battery, based on a prediction value of generated power of the renewable energy power generator, a prediction value of demanded power of the control device, and a prediction value of demanded power of the load on an assumption that power is supplied under a predetermined power supply limit;
• a determination part configured to determine whether or not charge or discharge of the storage battery with power matching the prediction value of the charged/discharged power of the storage battery is possible;
• a changing part configured to change details of the power supply limit so that the power supply limit for the load is tightened when it is determined that the charge or discharge of the storage battery is not possible;
• and
• a limit data output part configured to output limit data recording a detail of the power supply limit when it is determined that the charge or discharge of the storage battery is possible.

An operation method of an independent system including a renewable energy power generator, a storage battery, a control device, and a load, the operation method comprising the steps of:

• calculating a prediction value of charged/discharged power of the storage battery, based on a prediction value of generated power of the renewable energy power generator, a prediction value of demanded power of the control device, and a prediction value of demanded power of the load on an assumption that power is supplied under a predetermined power supply limit;
• determining whether or not charge or discharge of the storage battery with power matching the prediction value of the charged/discharged power of the storage battery is possible;
• changing details of the power supply limit so that the power supply limit for the load is tightened when it is determined that the charge or discharge of the storage battery is not possible;
• and
• outputting limit data indicating a detail of the power supply limit when it is determined that the charge or discharge of the storage battery is possible.