The Best Efficiency Point is the point at which the pump operates at the maximum flow efficiency. The Best Efficiency Point is mentioned in the efficiency curves of the pump mentioned by the manufacturer.
The pump should be operated at or near the Best Efficiency Point for maximum Efficiency. The Best Efficiency Point in the pump is chiefly dependent on the design of the impeller and its speed.
Operating the pump at the BEP means that the prime mover has to spend less power to drive the pump. This improves the energy efficiency