The real cost of running an electric motor

When ordering an electric motor, it’s easy to focus on the purchase price. However, the up-front payment is a drop in the ocean compared to the motor’s electricity demand over its lifetime. During a 20-year period of continuous operation, a typical motor will use over 400 times its purchase price in energy costs, with maintenance expenditure on top of that. In addition, should the motor break down, there’s the cost of lost production to consider.

So how do you go about calculating the total cost of electric motor ownership? ABB have developed a simple formula which considers:

•          Purchase cost
•          Running cost
•          Cost of not running, i.e. maintenance and unplanned downtime

By dividing the purchase price by the cost of ownership, a ratio is produced which can guide the user when ordering a motor.

For example, a 45 kW motor costing £1,700 with 94.1% efficiency running for 6,000 hours per year would cost £2,105,454 over a typical 20-year life. (These figures assume an average electricity price of £0.08/kWh and an annual downtime cost of £80,000.)

The cost of ownership ratio resulting from this calculation is 0.0008 (if the purchase price matched the cost of ownership then the ratio would be one), meaning the initial equipment outlay is a fraction of the long-term running costs. Why not do the calculation on motors for your process and see for yourself?

Alternatively, if you’d like us to help you get an idea of the best-value electric motor for your application in the long run, call Paul Scott on 01621 868138 or email paul@gibbonsgroup.co.uk.