Tim Gorter

PV-powered boats: Evaluation of design parameters

For about 150 PV boats which have been built during the last 30 years, we evaluated PV, mechanical and performance characteristics. From this evaluation followed that PV boats under 10 meters are most feasible to be equipped with preferably low weight PV modules of approximately 2kWp for electric propulsion. Most boats are equipped with PV with a surface area between 5m2 and 10m2 (78%). For boat length, 54% is between 4m and 8m. Most boats weigh up to 1000kg (56%). However, a large share of PV boats weighs much more: up to 85.000kg. Best performing PV boats — when considering speed and electrical efficiency-weigh around 250kg. The latter have a weight [t]/PV [kWp] ratio of around 1:2. In general, we notice under dimensioned PV systems installed on PV powered boats. In order to evaluate PV boat design parameters, we collected and evaluated the properties of 150 boats for commercial, recreational and private purposes. We evaluated PV boat design problems which lead to recommendations for improved designs of PV integrated boats. Among others, the hull choice may vary for different situations in which a boat is used; therefore a right hull needs to be selected carefully fitting sailing circumstances.

Scenario-based simulation of PV boats in an early design stage

In our paper, we present a new model for PV boats named RhinoSimSol, which is supposed to support simulation of the design of PV boats to evaluate PV boat performance in an early design stage. The model comprises various algorithms such as for solar trajectory and irradiance calculations to determine indicators of the PV boats performance in an early design stage. In order to determine these indicators for PV boats, scenarios can be used which let the user chose various options, such as a sailing route, start time of sailing and time of year. In order to demonstrate the functionality of RhinoSimSol, we executed 54 simulations with various combinations of 9 PV modules and 6 batteries. The performance parameters we compared were 1) maximum average speed for a 30km trajectory, 2) autonomy of the PV system with an average speed of 12km/h and 3) the PV system component cost. The results of these 54 simulations, speed, autonomy and cost for the PV system, were compared with an actual PV system on an existing PV boat. Performance of PV boats are optimistic compared with real monitored data: 76% overestimated. This suggest the following could be improved: more PV system components, such as MPPTs, and a more accurate irradiation model. Our simulation approach in Rhino shows that it can help determine and improve the performance of PV boats in an early stage of development.