An audit recommended reducing the pump size from 45kW to 18kW to reduce water flow rate and friction head losses along with a variable speed drive due to the varying height of irrigation blocks. The farm will reduce pumping costs by nearly $3,200 per year with a payback of just over 4 years. A 15kW solar PV system will save an additional $6,000 per year with a payback of just over 3 years.
The case study provides an estimate of the costs and benefits of replacing a 36hp diesel irrigation pump two options: a mains connected 15kW pump or a 19kW pump powered by a 20kW solar array to get paybacks of 11 or 6 years respectively. The case study also compares the cost for a new pump of a 7.5kW mains connected pump and a 9.5kW pump powered by a 10kW solar array, to find a payback period of less than 1 year. The farmer would save over $77,000 on pumping costs over 10 years by installing solar pumping in both applications.
An audit of a Mundubbera Citrus farm recommended fitting variable speed drives to pumps, and a 30kW solar PV system. The farmer has implemented the findings, reducing the pump size as well, and adding over 80kW of Solar PV to save over $41,000 per year in electricity costs.
A Cairns Cold Storage business cut their electricity usage by 30% by upgrading plant and equipment such as efficient chillers and pumps, variable speed drives and smart controls.
See How Lower Burdekin Water Board cut their power consumption by 58,000kWh and demand by 105kVA resulting in annual cost savings of $20,000 or 25% at the Kilrie Gully pump station.
See how Gold Coast Tiger Prawns saved $40,000 per year in demand charges by fitting Variable Speed Drives to main pumps and the conveyors in the processing plant – as well as Power Factor Correction.
An energy audit for the on-site electricity usage recommended the installation of variable speed controls on pumps, replacement pumps with more energy efficient drive units, hot water system replacement, lighting replacement, air conditioning upgrade options & installation of solar photovoltaic system.
The irrigation audit identified energy savings of 29% and a payback period of 1.3 years with a change to pump operations, installation of a variable speed drive to a 75kW pump and replacing the pump impellor with a full-size version. The audit also found up to $3,500 in savings available with a change in tariff.
The irrigation energy audit recommended adding variable speed drives to two dam pumps as they have varying duties in supplying centre pivot irrigators. The audit also recommended upgrading 100mm steel main pipe for transfer pumping to 125mm plastic. These initiatives would result in energy savings of over $41,000 per year and a payback period of around 1.5 years.