While in Mundubbera recently, the Energy Savers team followed up with a visit to a citrus orchard, assessing results from an audit carried out in 2014. The farm has implemented audit recommendations, installing an 82.8kw solar system and two new bore pumps with variable speed drives. You can view the case study HERE.
The orchard is managed in such a way that lowering pre-audit operating costs from implementation of audit recommendations was the main driver. The new irrigation pumps with variable speed drives (VSD) have proven their worth not only in reduced energy use and operating costs, but also by managing water pressure and application efficiency. In place of throttling pumps under full load, VSD pumps can improve energy efficiency by 10-60 per cent. This is achieved by the pump operating at what is called the best efficiency point (BEP) for a given pressure, controlling flow at the end of the irrigation system.
Although an increase in productivity was not the aim of the audit, the owner considers it is possible, and that currently the farm has reduced its energy and water costs per unit of output.
Implementing audit recommendations was initially challenging, due to the high capital costs and uncertainty around the concept. The solar system proved tricky in the early phases, the need to replace invertors due to design issues meant delays in operational capacity. Sizing solar systems accurately for your requirements is essential in utilising the power produced and enabling any potential export of power back to the grid. Ensuring an accurately sized system can see your business lower operating costs, with possible reductions in power bills under Ergon’s anytime demand tariffs. Issues aside, the farm highly recommends adopting the changes which have reduced operating costs and emissions directly related to energy use.