This case study summarises the outcomes from audits conducted on 41 Queensland Horticulture farms.
A recent energy audit showed how improving the current irrigation system can lead to energy and cost savings. The recommendations explored in the audit included refurbishment of 4 irrigation pumps and install Variable Speed Control in 5 pivot pumps.
Of the energy-saving opportunities evaluated, three initiatives were identified with potential energy savings of 38%, a combined payback period of 8.4 years and carbon savings of 37 tCO2-e per year.
Of the energy-saving opportunities evaluated, two initiatives were identified with potential energy savings of 17%, a combined payback period of 2.6 years and carbon savings of 7.4 tCO2-e per year.
Of the energy-saving opportunities evaluated, four initiatives were identified with potential energy savings of 10%, a combined payback period of 2.8 years and carbon savings of 79 tCO2-e per year.
This case study summarises the outcomes from audits conducted on all 180 Queensland farms in the Energy Savers Plus Program (ESPPE).
Of the energy-saving opportunities evaluated, one initiative was identified with potential energy savings of 30%, a payback period of 3.7 years and carbon savings of 5.3t CO2-e per year.
A mixed farming enterprise located in the Bundaberg region growing sugarcane, rockmelons, tomatoes and macadamia nuts could save 31% of energy consumption through irrigation improvements.
This case shows the potential savings by replacing the current irrigation pump with a more efficient unit. It further explores the connection between management practices, water, and the additional advantages that an energy and irrigation audit can provide.
The farm, near Stanthorpe, produces a large variety of horticultural products on an area of approximately 30 ha and could save up to 17 per cent off its energy bills after implementing an farm energy audit recommendation to replace the cold room condenser unit.
A Stanthorpe farm producing an average of 300 tonnes of stonefruit per year from 40ha could save 77% off its energy and diesel bills after implementing energy audit recommendations to upgrade their lights to LED as well as to replace the diesel pump with a solar system.
A farm in Mundubbera producing a variety of citrus and mangoes will benefit by implementation of recommendations in a recent energy audit. The farm could save up to 7% of the site total energy use, and approximately $90,000 p.a. with an average payback period of 5.5 years, and estimated carbon reductions of 85.3 t CO2-e per annum.
A Mareeba banana farm is on track to save 32% off their power bill for one of their pump stations with a new variable speed drive and a tariff change recommended in the Energy Savers audit. They are also getting more even watering and expect to cut maintenance costs!
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 can reduce energy consumption and costs by implementing the recommendations of an Energy Savings Program. The farm has already implemented VSD on 8 pumps, reducing the total energy consumption on farm by 28%. Further savings can be achieved by upgrading irrigation, refrigeration and hot water systems, with energy savings estimated as 12% of already reduced farm energy consumption.
The audit identified a range of energy saving initiatives 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 cost savings from all identified projects is nearly $50,000, with carbon reductions of 57.2 t CO2-e per annum.
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, with carbon emission reductions of 15 t CO2-e per annum.
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 and carbon savings of 43.4 t CO2-e per year. 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 irrigation opportunities for a new site, between a new 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 $9,000 on pumping costs over 6 years by installing solar pumping to replace the current diesel pump, with energy savings of 71% and emission reductions of 86.7 t CO2-e per annum.
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. Carbon savings have been estimated as 29.4 t CO2-e per annum.
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 with 156.9 t CO2-e of emission savings per annum.
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. Additional benefits include emission reductions of 150.3 t CO2-e per year.
The irrigation audit identified a number of opportunities on site including modifying pipe systems to reduce pressure loss, impellor modifications and installation of variable speed drives. Energy savings of 16% with a payback of 1.3 years were identified. The audit also identified up to $11,000 available by reviewing the tariff pricing structure for the pumps. Emission savings have been estimated to be 52 t CO2-e.
The irrigation energy audit identified that upgrading the existing filter and simplifying the pipework would reduce head losses by 50kPA, resulting in an energy saving of 12% with carbon emission reductions of 1.5 t CO2-e per annum.
The irrigation energy audit assessed a number of pumps and motors, recommending the installation of variable speed drives on each of the pumps to allow system pressure to be reduced by 100 kPa. These initiatives will reduce energy consumption by 18% with a payback of 4.2 years and carbon emission reductions of 18.7 t CO2-e per annum.
This irrigation energy audit recommended replacing two in-line centrifugal pumps with a single irrigation pump and Variable Speed Drive with energy savings of 34%. A 5kW solar system providing 39% of the sites energy was also evaluated, with carbon emission reductions of 5.2 t CO2-e per annum.
The audit recommended the replacement of a 50kW pump which is over-sized for the duty requirement which would give an energy saving of 56% and a payback period of around 8 years. In addition, changing tariff and switching pump operation to off-peak hours would save an additional $1,200 per year. Annual emission savings have been estimated to be 3 t CO2-e.
The audit recommended replacing a replacing a 55kW pump and motor with a smaller and more efficient pump and motor with an annual cost saving over $2,000 and a payback period of just over 7 years. Emission savings have been estimated to be 7.4 t CO2-e per year.
A range of initiatives were identified including replacing some pumps and motors with new pumps and variable speed drives, with a payback period of 2.8 years and annual cost savings of around $16,500. An extra $10,000 annual saving is potentially available at the site by reviewing the tariffs of the pump stations. Emission savings have been estimated to be 27.1 t CO2-e per year.
The audit of this vineyard and winemaker evaluated a number of actions with varying payback periods, including insulation, replacement of compressors, lighting controls and disconnecting unused pumps. Two initiatives had a payback period of around 3 years including insulation and disconnecting unused pumps. The audit also found a tariff review might save the business over $2,500 per year. Emission savings have been estimated to be 1.2 t CO2-e per year.
The audit recommended replacing refrigeration compressors and installing a 2kW solar photovoltaic system at a Stanthorpe Tomato and Capsicum Farm. The audit calculated approximately $30,000 in savings over 10 years, with payback periods at just over 4 years and emission savings of 6 tCO2-e per year. Additional savings would be available by changing electricity tariffs.
An energy audit recommended installing variable speed control on evaporator fans, replacing T8 cold room lighting with LEDs and a number of options for optimising refrigeration including thermal energy storage. Although the refrigeration projects have a long payback period, the variable speed controls and lighting would save over $7,000 per year with a payback of nearly 4 years. The farmer has decided to implement the lighting upgrades in the cold room, with 1% of total energy savings, around $1,500 per year and emission savings of 5 t CO2-e per annum.
An energy audit identified an opportunity to improve the air conditioning system for growing mushrooms, achieving annual electricity savings of $9,000 and demand saving of 23kW, which could potentially save around $400 per month in demand charges. Additional operating profits given increases in product volume are $442,000 per year. Emission savings have been estimated to be 34.3 t CO2-e per year.