More than half of Tasmanian farmers could be paying less in energy costs for irrigation, according to a leading national expert in irrigation management.
Irrigation and Water Management Theme Leader at the National Centre for Engineering in Agriculture Dr Joseph Foley said that between 50-70 per cent of farmers were paying more than they should in energy costs to run pivots and this is often linked to misconceptions about saving money with off-peak electricity rates.
“I have seen on a regular basis people trying to chase the low-cost tariffs that are offered over the weekend,” Dr Foley said.
“They build and design a machine to do all the irrigation in a smaller number of hours at these off-peak times, which results in both a higher flow-rate and a higher head loss.
“This means the energy cost is much higher on a per megalitre applied basis.
“By chasing those off-peak hours over the week they are actually increasing their total energy bill.”
The preliminary results of a project by the Tasmanian Institute of Agriculture (TIA) also suggest that the range of costs farmers are paying for energy vary significantly.
The Smarter Irrigation for Profit project, led by TIA, has established five pivot irrigated pasture sites on dairy farms in North and North-West Tasmania to collect data on power usage, water use, soil moisture and weather.
Preliminary results from the first season suggest that the amount of power being used by some farmers to pump water is excessive and significant savings could be made.
Based on a tariff of 23c/kWh the cost of applying 1ML of irrigation water ranged from $26/ML to $181/ML.
Simple modifications could lead to savings of more than $50/ML for some sites, (about $200/Ha), which equates to a savings of more than $8000 per year for a 40-hectare pivot.
The Smarter Irrigation for Profit project is supported by funding from the Australian Government Department of Agriculture and Water Resources as part of its Rural Research and Development for Profit program, Dairy Australia and TIA.
Research and Development Team Leader at the TIA Dairy Centre and Chief Investigator on the project, Dr James Hills said the project was using precision irrigation to help maximise pasture production.
“There is a pressing need for industry to find and adopt innovative practices and technologies that utilise water as efficiently as possible,” Dr Hills said.
Dr Foley, who is also a collaborator on the project, said he was not surprised by the results.
“It is not uncommon to see such a big difference in energy use per megalitre applied, " Dr Foley said.
“As growers come into the irrigated industry, they often don’t know about the information and resources that are available to help them make decisions about system design.
“One thing I always say is that they need to talk to and learn from other growers across the state that have been using centre pivot systems for a long period of time.
“This is especially true with the new irrigation schemes in Tasmania, where we are seeing irrigation in areas where there has been little to no long-term irrigation before.”