Environment and Heritage) to undertake a pump efficiency pilot project to assess the
energy productivity of on-farm irrigation equipment in rural areas. The pump
efficiency pilot consistent of 11 large irrigation businesses and an irrigation infrastructure operator in regional areas and was conducted over a period of 18 months
(NSW OEH 2017). Following extensive on-farm and off-farm assessment of the
existing pumping equipment, the pilot found that many irrigation pumps were ‘(un)
fit for purpose, had discharge heights that were too high, suffered from valve and
suction entry issues and had issues with belts and pump cavitation’ (NSW OEH
2017). Each of these issues caused higher than necessary electricity costs for the
irrigation businesses. Overall, the pilot estimated that through small-scale adjustments to the existing irrigation equipment and electricity tariff adjustments, pilot
participants would be able to save between AUD$31,000 and AUD$314,000 in their
overall electricity costs (NSW OEH 2017). In terms of individual results, one of the
case studies highlighted the significant benefits from the installation of power factor
correction units on pumping equipment. An irrigated cotton producer in northern
NSW who used both diesel and electricity to operate his irrigation pumps and
on-farm infrastructure had a yearly electricity consumption of around 2700 MWh,
and diesel consumption is approximately 173,000 GJ. Several irrigation pumps were
running on electricity and were billed on ‘obsolete’ network tariffs. Due to a recent
change in the National Electricity Rules (NER), the cotton grower was moved to new
‘demand-based tariffs’ (AEMC 2014) causing the grower to incur an additional
AUD$100,000 in costs to operate his four irrigation pumps. However, the pump
efficiency audit found that if the grower installs power factor correction units at all
pump sites, there is a reduction in maximum demand, saving over AUD$50,000 per
annum under the new tariff structure arrangements (NSW OEH 2017). A second
case study showcased how the use of off-peak periods and an optimised use of the
on-farm irrigation equipment could reduce overall costs for the growers. A family
farm in central NSW grew wheat and cotton on approximately 900 ha (212 ha under
pivot irrigation). The property’s yearly electricity consumption was approximately
1400 MWh, and the yearly diesel consumption is 7300 GJ. One of the river pumps
was run on electricity. Comparing the usage profile over 12 months, it was determined that if the pump could be run at 85 kW constantly, it would avoid being
captured under demand-based tariffs. Hence, if the grower ran the pump during ‘offpeak’ times (except during heavy irrigation use periods such as January and
October), they would be able to save approximately AUD$12,000 a year (NSW
OEH 2017). One of the pumps in the second case study drew water directly from the
main irrigation supply channel. This process delivered water to six pivots that
irrigated the northern part of the property. Up to three pivots could be supplied at
any one time. The flow rate delivered by the pump was determined by the number of
pivots operating and was controlled by the line pressure at the pump. The line
pressure was a fixed value based on the pressure required to run three pivots. Usually
not all three pivots were operating at the same time. The audits showed that if the
grower was able to run three pivots instead of two, changing the irrigation patterns
across farm, they would be able to save an additional AUD$12,000 a year. If only
one pivot was run, the cost would be about AUD$50,000 greater than if three pivots
7 Water Security: Challenges to the Irrigation Water-Energy Nexus in Australia
105
energy productivity of on-farm irrigation equipment in rural areas. The pump
efficiency pilot consistent of 11 large irrigation businesses and an irrigation infrastructure operator in regional areas and was conducted over a period of 18 months
(NSW OEH 2017). Following extensive on-farm and off-farm assessment of the
existing pumping equipment, the pilot found that many irrigation pumps were ‘(un)
fit for purpose, had discharge heights that were too high, suffered from valve and
suction entry issues and had issues with belts and pump cavitation’ (NSW OEH
2017). Each of these issues caused higher than necessary electricity costs for the
irrigation businesses. Overall, the pilot estimated that through small-scale adjustments to the existing irrigation equipment and electricity tariff adjustments, pilot
participants would be able to save between AUD$31,000 and AUD$314,000 in their
overall electricity costs (NSW OEH 2017). In terms of individual results, one of the
case studies highlighted the significant benefits from the installation of power factor
correction units on pumping equipment. An irrigated cotton producer in northern
NSW who used both diesel and electricity to operate his irrigation pumps and
on-farm infrastructure had a yearly electricity consumption of around 2700 MWh,
and diesel consumption is approximately 173,000 GJ. Several irrigation pumps were
running on electricity and were billed on ‘obsolete’ network tariffs. Due to a recent
change in the National Electricity Rules (NER), the cotton grower was moved to new
‘demand-based tariffs’ (AEMC 2014) causing the grower to incur an additional
AUD$100,000 in costs to operate his four irrigation pumps. However, the pump
efficiency audit found that if the grower installs power factor correction units at all
pump sites, there is a reduction in maximum demand, saving over AUD$50,000 per
annum under the new tariff structure arrangements (NSW OEH 2017). A second
case study showcased how the use of off-peak periods and an optimised use of the
on-farm irrigation equipment could reduce overall costs for the growers. A family
farm in central NSW grew wheat and cotton on approximately 900 ha (212 ha under
pivot irrigation). The property’s yearly electricity consumption was approximately
1400 MWh, and the yearly diesel consumption is 7300 GJ. One of the river pumps
was run on electricity. Comparing the usage profile over 12 months, it was determined that if the pump could be run at 85 kW constantly, it would avoid being
captured under demand-based tariffs. Hence, if the grower ran the pump during ‘offpeak’ times (except during heavy irrigation use periods such as January and
October), they would be able to save approximately AUD$12,000 a year (NSW
OEH 2017). One of the pumps in the second case study drew water directly from the
main irrigation supply channel. This process delivered water to six pivots that
irrigated the northern part of the property. Up to three pivots could be supplied at
any one time. The flow rate delivered by the pump was determined by the number of
pivots operating and was controlled by the line pressure at the pump. The line
pressure was a fixed value based on the pressure required to run three pivots. Usually
not all three pivots were operating at the same time. The audits showed that if the
grower was able to run three pivots instead of two, changing the irrigation patterns
across farm, they would be able to save an additional AUD$12,000 a year. If only
one pivot was run, the cost would be about AUD$50,000 greater than if three pivots
7 Water Security: Challenges to the Irrigation Water-Energy Nexus in Australia
105