Golden North is a manufacturer of premium ice cream and frozen yoghurt. Its South Australian facility at Laura consumes 6930 gigajoules (GJ) of electricity per annum, about 75% of which is used by the refrigeration plant. Energy assessment identified numerous areas for savings through energy efficiency improvements, including replacing inefficient compressors with a single crew compressor (and using variable speed drives to ensure it runs efficiently); installation of hot water exchangers for oil cooling and installing variable speed fans.
The average small-medium retail business can use 80,000 kilowatt hours (kWh) of electricity a year. This factsheet shows how one business, Bottle King Liquor, saved on energy costs to run its fridges. By installing fridge timers, the business saved $135 a year for the running costs of each of its 7 drinks fridges, a $950 annual saving that was paid back in less than 2 months.
The 14 cold storage rooms at Savio’s, a fruit packing house in Queensland, are controlled by 3 large ammonia compressors, which an audit showed consumed over 435,000kWh (costing $95,000) in ten months. By avoiding demand changes which account for 40% of Savio’s total electricity costs, the business could save $5500 a year by shutting down equipment at certain times.
At the JW Kirkwood Ticehurst Orchard in Tasmania, 58% of the annual electricity spend of around $90,000 is for refrigeration of its cool rooms and other systems. In WA, Newton Brothers packhouse and cold storage spends 70% of its $350,000 annual electricity costs on cold storage. Both could save money by reducing the head pressure in their refrigeration units. this would cost around $5000, save between $2500 and $3500 a year and have a payback period of just 1-2 years.
At Capilano’s Richlands honey production facility, electricity and natural gas are the primary energy sources and input costs. Of the 18,000 gigajoule (GJ) (a cost of $580,000) used on site, 25% is used by thermal loads of pasteurisation and hot water generation. An assessment took into consideration upcoming business changes (the build of a new facility was pending) and advised Capilano about opportunities to save money on lighting, solar PV, thermal system insulation and heat recovery, and compressed air heat recovery.
Caernarvon Orchard in Orange, New South Wales, produces and packs 4500 tonnes of apples and 800 tonnes of cherries per annum. About 5% of its annual electricity spend is on lighting (around $3400 pa). An energy audit found that replacing high bay lighting fixtures with light emitting diodes (LEDs) would save $2120 a year (from a one off investment of $5600). Savings would also come from using electronic lighting ballasts, and replacing fluorescent tubes.
The Incitec Pivot plant at Gibson Island in Queensland used about 13 peta joules (PJ) of energy in 2008–09 in the manufacture of nitrogen-based fertilisers. This case study describes 3 projects estimated to save 150,000 giga joules (GJ) of energy annually. This case study was developed as part of the Energy Efficiency Opportunities (EEGO) program.
Bakers Delight’s designed a showcase bakery at its operation in Mascot. The bakery showcased best-practice building design, baking procedures and equipment efficiency, achieving a 32% reduction in annual energy costs compared to a standard Bakers Delight bakery. This was achieved without impacting on product quality, customer satisfaction or staff comfort.
A team-based approach relying on ‘people know-how’, combined with sound measuring and monitoring, has enabled a dairy processing company to gain impressive bottom line savings. The 12 month pilot project, which measured energy use in the various stages of milk processing at the Rochester (Victoria) Branch of Murray Goulburn Cooperative, achieved savings of $400,000 a year with a reduction in greenhouse gas emissions of 3,500 tonnes.
The purpose of these case studies is to demonstrate how systems optimisation can be used to improve energy efficiency and productivity in a wide range of industrial applications. They were developed through companies' participation in the Energy Efficiency Opportunities (EEO) program. Examples from 3 companies highlight different aspect of systems optimisation: