Tactical Research Fund - Empowering Industry: energy audit of prawn trawler with auxiliary sail power
University of Tasmania (UTAS)
Giles A. Thomas
Commercial fishing is one of the most energy intensive food production methods today and the Australian industry consumes approximately 205 million litres of diesel fuel per annum. The fishing industry needs to radically improve the energy efficiency of its operations primarily due to the rising cost of fuel and its effect on operating margins. The recent rapid increase in cost of diesel has reduced margins to such a low level that it is rapidly becoming uneconomical for operators to continue to trade. This has significant flow-on effects down the whole production-processing-retail chain. In addition there is a global need to reduce the emissions of oxides of nitrogen (NOx) and carbon dioxide (CO2) from fossil fuel combustion. The global fisheries industries emit annually more than 130 million tonnes of CO2 into the atmosphere. Trawling is a very energy intensive fishing method, for example Australian prawn trawlers incur fuel costs of approximately 35% of total production costs. The use of alternative auxiliary powering systems, such as sails, has the potential to radically reduce fuel consumption by a combination of providing supplementary propulsive thrust and reducing vessel motions and consequent drag. Several fishers in Australia have installed sails onto their vessels with the aim of reducing fuel consumption, but no investigations have been conducted to ascertain the effect the auxiliary systems actually have on fuel consumption, performance and costs. The results from an energy audit on such a vessel would provide valuable information to other fishers on the benefits, or otherwise, of fitting such a system to their vessel. The need for this work was highlighted by the results from recent FRDC sponsored energy audits of fishing vessels. The 1st International Symposium on Energy Efficiency in Fishing was held in May 2010 and clearly emphasised the need for continuing RD&E in this area.
1. Energy audit (level 2) on prawn trawler fitted with auxiliary sail system.
2. Collect data on effect of use of sail system on fuel consumption in varying environmental conditions.
3. Analyse energy audit data to determine effect of sail system on fuel consumption.
4. Disseminate information on effect of sail auxiliary power system to owners and operators of fishing vessels.
Principal Investigator: Giles Thomas
Key Words: Prawn trawling, Sails, Energy audit, Fuel Consumption
Summary: Commercial fishing in Australia uses approximately 205 million litres of diesel fuel per year. Active fishing techniques such as trawling consume large quantities of diesel fuel, predominantly for the propulsion power.
Russel Kilfoy is a prawn trawl fisherman based in Cairns, Queensland, targeting Leader, Endeavour, Tiger and Banana prawns. He has taken an active approach to the rising diesel fuel prices by incorporating sails as an auxiliary propulsion system onto his vessel in an attempt to reduce fuel usage. The FV Sea Lion was found to use 69% of its energy on board for propulsion, this highlighted that the best savings stand to be made by improving the propulsive efficiency.
The effect of the sails was recorded over a five day period on board the FV Sea Lion. It was found that up to 13% fuel savings could be made under certain conditions. If this data is extrapolated out over a normal 24 hour operating period, savings of up to 7.3% could be made on the total fuel usage per day. This demonstrates the positive impact that using auxiliary sail power can have on reducing fuel usage. However the successful application of sails as an auxiliary power source for fishing vessels will depend on each vessel’s hydrodynamic characteristics and operational profile.