VSD (Variable Speed Drive) and energy efficient motors

Baseline scenario:
• Installation of a new 22kW 4-pole motor which has an efficiency of 93.0%.
• Replacing a 22kW 4-pole single speed induction motor which has previously been rewound and has an efficiency of 80%.
• The motor is running continuously for 24 hours per day, 365 days per year.
• Electricity unit price is 9p/kWh.
• The 22kW motor drives a centrifugal pump which runs continuously circulating water around a closed loop.
• The VSD (Variable Speed Drive) is 95% efficient.
• The speed of the pump can be reduced by 20% without any noticeable reduction in the performance of the water system.

By installing a single VSD  (Variable Speed Drive) onto a 22kW pump, the potential annual savings are calculated as:

  • £11,865.
  • 131,833kWh
  • 69.1 tonnes CO2.