A generator is often sized around the largest short load peak even though average demand is much lower. Generator peak-shaving lets the inverter and battery contribute during those brief peaks, reducing the temporary burden on the generator. That can be useful when motors start while the generator is already carrying normal loads. The solar inverter does not eliminate the need to size the generator for sustained demand; instead, it helps manage short peaks so the generator is not forced to supply every transient by itself.
