The audit recommended replacing high pressure travelling guns with a low pressure boom irrigator and installing a variable speed drive to maintain 65psi at the booms. The project is expected to save 20% energy and has a payback period of 3 years.
The audit presented 2 options to improve the efficiency of an 18kW pump: upgrading to a high efficiency model, or adding an VSD, both of which would save nearly $4,000 per year and pay back within around 2 years.
The audit identified several energy efficiency opportunities including regular checks for leaks in the irrigation and compressed air systems and a lighting upgrade. The audit recommended a 10kW Solar PV system to complement energy efficiency practices already in place, to further cut power required from the grid by 35% to save over $4,000 per year with a payback of less than 5 years.
The audit recommended regular checking of cold room door seals to save up to 10% in refrigeration costs, along with incorporating 30kW Solar PV into a new shed being built at the site to offset pumping and refrigeration power consumption with a payback period of 4 years. Variable Speed Controls were recommended for 2 smaller pumps with a payback period of 7.7 years.
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.