Energy Assessments

Energy Savings at Municipal and Industrial Pumping Facilities

Energy costs for electric motors that drive large pumps account for much of the annual cost of operation of municipal and industrial pumping facilities. For example, a 250 hp pump and motor has an initial cost of around $30,000, but the cost to power that pump the first year will exceed $80,000 (at 6 cents/kwhr). The cost of electricity to power a large motor that operates more than 6000 hours per year can account for over 80% of the life cycle costs.

Most large pumps at municipal and industrial facilities are centrifugal designs, which should operate at an optimal flow rate and head condition, referred to as the Best Efficiency Point (BEP) on the pump curve. Many facilities have undergone changes in function from what they were originally designed to do. An assessment of the current system requirements will insure existing equipment is suitable for the task and in good repair.

Potential savings are identified using the software program "Pumping System Assessment Tool" (PSAT). This program requires data obtained from motor and pump nameplates, flow rates, suction and discharge pressures, power data obtained from electrical switchgear, and energy costs. Click for example screen from PSAT . Potential energy savings are calculated by comparing energy costs using existing equipment to costs for operating properly sized pumps and motors.