The hybrid energy storage inverter has the features of off-grid function and grid-connected function. Through advanced technology, it can meet the electricity demand of various end users. When the electricity is cheap, use mains to power the load and charge the battery. When the electricity is expensive, cuts off the mains, uses batteries to power the load, or sells electricity. It is also a device that can power the load directly by generating electricity from solar panels even without mains electricity and batteries. This advanced technology can save power bills for end users, improve the return on solar power systems investment , and provide convenience and flexibility.