Motors and power factor correction
Power factor correction of motors can result in significant energy savings. Find out how to calculate those savings and create energy savings certificates.
Industrial sites and large commercial buildings generally have a large numbers of electric motors in use to operate HVAC systems, lifts, a vast array of machinery and numerous processes.
The Energy Savings Scheme has provisions to create energy savings certificates for the sale or installation of high efficiency motors.
For commercial and industrial sites with large inductive loads, such as electric motors or fluorescent lighting, power factor can be low. Power factor correction can result in significant energy savings and certificate creation.
Using the High Efficiency Motor Energy Savings Formula
The number of eligible certificates for the purchase or sale of a high-efficiency motor depends on the following variables, the:
- rated output of the motor (kW)
- number of poles in the motor
- end-use of the equipment and the type of industry.
These variables determine the default factors defined in the ESS Rule, such as operating times and efficiency improvements. The energy savings certificates are calculated based on a lifetime ranging from 12 years for small motors up to 25 years for large motors.
Using the Power Factor Correction Energy Savings Formula
This calculation method uses two variables:
- the rating of the installed Power Factor Correction capacitors (in kVAr)
- the power factor after installation of the Power Factor Correction capacitors, in kW.
NSW regulations require that the power factor of a site must be a minimum of 0.9. Therefore, energy savings associated with power factor corrections from 0.9 up to a maximum of 0.98 will be eligible to create energy savings certificates.
The energy savings certificates are calculated based on a default lifetime of 10 years.
Using other methods to calculate energy savings
In some scenarios it could be beneficial to use alternative calculation methods:
- If you are upgrading an electric motor and that motor is operating in excess of the default values or efficiency improvements are greater than the default values.
- Installation of variable speed drives has resulted in savings that are larger than default values.
In these cases it will be beneficial to apply under the Project Impact Assessment Method or, depending on the project and scale, under the Metered Baseline Method.