23 results for Information paper and Cropping
Solar pumping can help offset the cost of traditional irrigation fuels. The more often a pump is run, the greater the opportunity for savings from solar. Solar pumps are reliant exclusively on the sun to provide power and therefore operate only during daylight hours unless coupled with battery/storage systems. Solar pumps may be a good option for lower water volume and daytime irrigation systems. As yet, affordable solar technology is unable to supply sufficient power to pump enough water for large-scale flood irrigation.
Farm-scale wind turbines for electricity generation have broad potential for application in rural Australia. Farmers can take advantage of existing land to install turbines and generate local electricity. The power generated can be used on farm, stored in batteries or sold back to the network.
Provided there is easy access to the electricity network, converting from diesel-driven to electric pumps will improve pumping efficiency and reduce costs. Typical efficiencies for electrical centrifugal pumps range between 70 and 80 per cent, whereas diesel pumps have an efficiency of just 30 to 40 per cent. Other advantages of electric pumps include lower maintenance requirements, less environmental impact and more easily implemented pump controls (such as variable speed drives).
Pump efficiency deteriorates over time, leading to energy wastage. Efficiency losses of between five and 15 per cent can occur after 10 years of operation. When pumps are maintained to restore efficiency close to its original point, significant energy savings can be achieved. Typically, a pump overhaul includes: replacement of wear rings, seals, bearings and if worn, the impeller; cleaning of internals; blast cleaning of externals; and applying new epoxy coating.
Irrigation pumps are typically over-specified at the design stage, resulting in significantly higher power consumption and operating costs. A pump is generally oversized when it is not operated at or within 20 percent of its best efficiency point (BEP), although it is normally considered acceptable if the duty point falls within 50 and 110 percent of the BEP flow rate. By replacing oversized pumps with smaller ones, energy and maintenance savings can be achieved due to lower power consumption requirements and less wear and tear.
The installation of variable speed drives (VSDs) on pumps can be an effective energy-saving measure. Lowering the speed of a motor by just 20 percent can produce an energy saving of up to 50 percent. Variable speed drives can be installed on all pumps, including those associated with HVAC systems. The VSD needs to be connected to a control signal and may also require installation of measurement devices or controllers, which typically are included in costing. The financial viability of installing a VSD depends on the motor application and operating hours. VSDs tend to be most economical when used on large pumps.
Manual control in grain drying operations with large variations in moisture often leads to significant overdrying or underdrying, and is highly inefficient from an energy point of view. Feedback-based automatic controllers can help to minimise energy consumption by controlling energy inputs more precisely to meet the needs of the product being processed. While preservation of grain quality is the primary benefit, energy savings of up to 20 percent can be achieved.
The pressure drops typical in compressed-air systems used on farm can result in energy losses greater than 35 percent. Pressure drops can be reduced by increasing the pipe/hose diameter to reduce friction, thereby helping to reduce flow losses; selecting rigid pipes made of smooth material to further reduce friction; minimising the length of pipe and components that increase joins (resulting in fewer smooth areas) and the likelihood of bends.
Leakage accounts for nearly one third of compressed-air energy consumption. A proactive leak repair and maintenance program should be followed for compressed-air systems. Applying repair and maintenance measures in a sustainable manner requires regular inspection and assessment of your system and engagement with equipment operators. The upside is that energy savings of up to 80 percent can be achieved.
Some farmers are unaware that their electricity bills can be reduced by improving the ‘power factor’ (PF) of their facilities. A poor power factor is analogous to a beer with too much head, when the head represents wasted energy. Networks penalise facilities with poor PFs by increasing ‘demand’ (or ‘capacity’) charges. Installing power factor correction devices can help ensure that on-farm electrical equipment uses the voltage provided by the network efficiently and that penalties are not applied as a result of the facility making unpredictable demands on the system.