This detailed case study shows how a comprehensive audit and collaboration between the auditor and local refrigeration specialist have significantly reduced cold room operating costs with annual savings of almost $20,000 and a payback period of a year and a quarter. Refrigeration energy consumption and demand have been almost halved.
The farmer installed variable speed drives on two 37kW pumps providing an annual cost saving of over $14,500 with a payback period of around 18 months. Other efficiencies were identified including some refrigeration improvements and a small Solar PV system which the farmer is yet to implement.
This case study shows how a Clare melon farm is reducing energy costs thanks to the energy savings program. The farms has reduced the energy cost for cold rooms and packing shed by 10 – 15% off their annual $250,000 bill. Further savings are being made with irrigation efficiencies.
The audit identified a range of energy saving initiaves in the packing sheds including refrigeration, lighting and the installation of Solar PV to supply some power. Three projects had a payback less than 5 years including the lighting and two Solar PV installations. The estimated annual savings from all identified projects is nearly $50,000.
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 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.
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 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.
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.