11 results for Information paper and Aquaculture
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).
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.
Chilling and refrigeration can account for more than half of a farm’s energy use. Cold chain technology has improved markedly over the past decade and the range of opportunities for farmers to save energy has expanded. This fact sheet provides an outline of the energy-saving opportunities in cooling and refrigeration, and details areas in which upgrades can improve the quality of your produce and its farm-gate value.
Energy-efficiency improvements of up to five per cent are possible if failed electric motors are replaced with high-efficiency models. High-efficiency motors are more expensive than standard motors but typically demonstrate good return on investment in the small motor range (up to 185 kW). Over a 10-year operating period for a motor, the purchase price represents only about two percent of the total motor installation and operating costs. Even a small improvement in motor operating efficiency can produce significant energy and cost savings.
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.
Installing variable speed drives (VSDs) on refrigeration evaporator fans enables fan speed to be modified to match varying cooling loads. At low loads, reducing the speed of a fan decreases the power requirement of its motor significantly: reducing fan speed by 20 percent can reduce power consumption by approximately 50 percent. Where cooling loads are relatively constant, multi-speed motors may be cheaper and more efficient than motors equipped with VSDs and should also be considered.
Voltage optimisation can achieve energy savings of between five and 20 percent in situations where mains voltage is higher than is needed by farm equipment. In addition to enabling energy savings, voltage optimisation units protect electrical devices from variation – surges or drops – in mains voltage. Purchasing considerations include the type of unit and the presence of electronic devices in the circuit. The installed cost of a VO unit typically ranges between $150/kVA and $300/kVA.
Solar photovoltaic (PV) electricity generation has wide application in rural Australia. Although the electricity generated by photovoltaic panels is intermittent, PV systems can help reduce electricity consumption from the network and provide other benefits such as reduced demand charges. Standalone systems using batteries or direct loads can also be used to power equipment, such as irrigation pumps, that are far from network connection points. Although solar PV systems can be scaled to provide all the electrical energy a farm requires, return on investment and needs analyses are essential to ensure farmers select systems of the proper type and size.
Research by NSW Farmers indicates that many farmers have not negotiated the best possible electricity contracts for their operations. Electricity bills are comprised of various charges, some of which are negotiable. The timing of going to market and taking a professional approach to contract development are also significant factors. Effective contract negotiation depends on acquiring a sound working knowledge of electricity market dynamics, the factors that determine pricing, and the terms retailers are likely to accept for a given property and time period.