Conducting in-person audits & developing a virtual audit tool for commercial fishing vessels in Alaska.
The Alaska Fisheries Development Foundation and the Alaska Longline Fishermen’s Association (ALFA) received funding from the National Oceanic and Atmospheric Administration in 2015 to develop a baseline of fishing vessel fuel consumption in Alaska that could be used to quantify future energy improvements. In addition, the project would develop a set of actionable energy conservation measures and a model of fuel consumption on fishing vessels. ALFA contracted Kempy Energetics to assist with all technical aspects of the project including conducting energy audits, identifying energy conservation measures and developing an interactive online web tool that fishermen can use to predict the impact of their decisions on fuel consumption.
In phase one of the project Kempy Energetics conducted dozens of energy audits on troll, seine, gill net and tender vessels. The audits included both sea trials with a duration of a few hours to measure the vessel’s propeller power curve under various conditions, as well as season-long recordings to determine the precise usage patterns of every energy consumer on board. For the sea trials, strain gauges were installed on the propeller shafts to measure mechanical torque and power, and flow meters were installed in the fuel supply and return lines to quantify fuel consumption simultaneously. A power quality analyzer was used to measure electrical loads and record their power factors. The flow meters remained installed for long term recordings and electrical current data loggers were also installed. Combining the long term current data with the short term power factor measurements enabled an accurate estimate of electrical power consumption throughout the fishing season. Pressure transducers were also installed in hydraulic systems to record pressure throughout the season. In order to estimate hydraulic power, we also recorded the pump displacement and rate of rotation throughout the season. The hydraulic power was then estimated as the product of pressure, displacement, and rotation rate.
In phase two of the project Kempy Energetics developed a model of vessel fuel consumption and energy conservation measures based on the data collected in phase one. The model shows how fuel is used by every system on several classes of vessel. The information is useful for identifying the systems that offer the most opportunity for fuel savings. For example, some refrigeration systems account for nearly half of a vessel’s total fuel consumption while in other cases propulsion alone accounts for 90% of total fuel consumption. The energy conservation measures that are relevant to these two vessels are very different.