峰时耗电量W1=200KWh×(3/10)=60KWh消耗电费60KWh×0.55元/KWh=33元谷时耗电量W2=200KWh×(7/10)=140KWh消耗电费140KWh×0.3元/KWh=42元共计33元+42元=75元之前电费200KWh×0.52元/KWh=104元节约104元-75元=29元