Pump efficiency and flow monitoring reduce energy wastage and improve profits. By monitoring the pump efficiency of a 115kW pump that delivers water to an irrigation system, savings of over $13,000 was realised. The pump operates 9 months of the year for 24 hours a day and only stops when the sprinkler system is moved to another section of the field or after significant rain.
The pump was not fitted with any monitoring equipment. At the time of monitoring the pump performance, the pump has been in operation for 7 years.
Actual pump performance:
The pump energy losses and flow were monitored using the thermodynamic method of determining pump efficiency. It was found that the pump wastes 5.56% more electricity than a new pump due to internal component wear. This resulted in a total energy wastage of 36,000 kWh per year.
Monitoring the pump performance also revealed that the pump was delivering 7% less water than expected which had a negative impact on the harvest.
The pump was taken out of service and all wearing parts were replaced. The impeller and pump casing were also cleaned. Following the pump refurbishment, the pump performed as per the manufacturer’s performance curves. The total cost of the repair work was $7,223.00.
- There was a noticeable improvement in the harvest. The nett increase in harvest which can be attributed to the improved pump performance will be more pertinent during periods of drought.
- The improvement in pump efficiency resulted in lower operating costs of the pump, hence an increase in corporate profitability.
The refurbished pump will save $6,480.00* in electricity cost per year. If the pump repair costs and the investment of installing pump efficiency monitoring equipment is depreciated over 4 years, the return on capital investment will be over 120% as shown below.
|Pump efficiency monitor||($4,375.00)|
|Flowmeter option||($ 900.00)|
|Return on investment||US $13,422.00|
* Electricity Cost = 18c/kWh