Using a computer based selection model for sizing of solar panels and battery back-up systems for use in a floating in-pond raceway

Abstract

The In-pond Raceway (IPR) is a relatively new option for production aquaculture, which depends on water moving devices to provide constant flow. Failure of these devices will often result in a catastrophic loss of fish in the system. Thus, robust power backup systems are necessary to mitigate risk in the event of prolonged power outage. Because these systems must be dependable and many suitable locations for these raceways are in ponds in remote locations, farmers have considered utilizing off-grid solar photovoltaic (PV) systems with battery storage. PV with battery storage eliminates the expense of running utility power to remote areas and eliminates the associated risk of power failure when these lines go down. However, the PV and battery storage must be properly sized to ensure continuously available power. This study modeled energy requirements using a daily energy balance for these unique systems. The model was then utilized to determine whether sized systems could withstand varying electric loads based on monitored hourly climatological conditions at seven different locations within the state of Kentucky in the United States. Determining the appropriate size was an iterative process, where the battery storage and PV array were incrementally increased until the model predicted that the system would provide continuous power year-round. The model was also used to examine the effects of undersized systems. Energy depletion events (when not enough energy remained to drive the water moving device) were clustered in groups of multiple days in winter months over the twenty-two-year dataset. Therefore, undersized systems may be appropriate if there was no intention of stocking fish in winter. Establishing this model led to the development of a design decision support tool aimed at potential new Aquaculture producers and a series of recommendation tables, with the intention of streamlining the initial design process for this novel technology.