XVI Newsletter TSB

XVI NEWSLET TER Covid-19 Updates on SR 02 Hydrogen Vessel



After all the success achieved in the last year with the SR-02 in the Monaco Solar & Energy Boat Challenge competition with the conquest of the second place on A-Class, a new season started and, consequently, new challenges arrived. For this season, Técnico Solar Boat Team is developing two projects: the first one is an update of the SR02 and the second is a hydrogen-powered vessel. Information Associação TSB - Técnico Solar Boat Av. Rovisco Pais, 1049-001 Lisboa +351 21 841 9506

TSB Team 2020 We present the team for this season. After the fantastic year that goals established for this season.Let’s work!! Técnico Solar Boat

has passed, we are even more motivated to work and reach the Técnico Solar Boat

New Members We want to congratulate and give a warm welcome to the new members of the TSB team. Hydrogen Propulsion André Ferreira Diogo Gomes Francisco Dinis Igor Oliveira João Alves Luis Azevedo Técnico Solar Boat

Mariana Silva Luiz Jesus Rafael Jerónimo Management and Marketing Ana Vieira Beatriz Velosa Luiz Freitas Mariana Nunes Técnico Solar Boat

Covid-19 Our main goal for this new season was to participate in the Monaco competition with our two prototypes. Unfortunately, the competition ded to continue our work. Despite the present situation, Covid-19, w from home. We are completely motivated to finish the SR-02 and start of the hydrogen vessel. To test and show our prototypes, we decided to do a trip through Por the whole public, not only the world of engineering and industry. Mor be more autonomous since we want to include these types of events TSB tour 2020 So, the main idea is to go through certain routes with our vessel and the rest of the time will be dedicated to show our prototypes and explain our concept to the community that we’ll encounter throughout this journey. This trip will allow us to demonstrate our vessel to the communi- ty, as well as, present our sponsors, which are fundamental to the accomplishment of these projects. For this trip, we have planned four routes throughout Portugal, throughout 3 weeks Técnico Solar Boat

Solar & Energy Boat Challenge was cancelled, but we’ve deci- we didn’t stop, we kept working t the construction of the cockpit rtugal, to present our project to reover, this trip will allow us to s in the objectives of the season. Técnico Solar Boat

SR02 Updates In this season of competitions, the Design and Composites de- partment began by repairing some components from our solar prototype, SR02. Our main goal was to fill all the porous areas in the junction of our deck with the hull and to improve the external leakage of our side floaters, preventing the entrance of water, disadvantageous for our boat’s stability. In this regard, we applied a good topcoat to achieve a high-quality finish. Técnico Solar Boat

Furthermore, we reinforced our hull by laminating stringers in watertight zones to provide the rigidity needed for the implemen- tation of hydrofoils. We also laminated the support for a sensor essential for the electrical control of the foils. Finally, other small improvements we made were the reposition of our ventilation tubes and the opening of our cockpit, according to the technical rules of the Solar Class of Monaco Solar and Energy Boat Challenge. Técnico Solar Boat

SR02 Updates Hydrofoils We decided to implement a hydrofoils system (3 in total) in the SR-02 vessel. These submerged wings allow the boat to rise above the water when enough speed is reached. This system allows the vessel to be faster and more efficient be- cause it reduces the boat’s drag in a drastic way, allowing the boat to move faster with the same power consumption. Over these past months, we assembled the hydrofoil system which is electrically controlled. We had to re-machine some parts as they did not meet the required tolerance. We want to especially thank Igus for the quickness with which they send us their iglidur polymer bushings that were essential for us to complete the as- sembly. In the last few weeks, we were able to test the system out on the water, in those tests we flew for the first time and we broke our previous speed record, reaching 35.3 km/h. Técnico Solar Boat

Those flights were not stable enough and we are still working on the control algorithm. In order to have a leveled flight at different speeds the rear foil must be controlled independently, the mechanism that allows this is being remade because the chosen motor wasn’t powerful enough to change the angle of the foil. For the first test, we had to limit the boat to a specific speed in order to maintain a leveled flight. This was achieved using a “Cruise Control” algorithm that adjusts the motor power needed to maintain the desired speed. We are currently designing new hydrofoils to be manufactured out of carbon fiber, unlike the current ones that are machined from aluminium. This design choice makes it easier and faster to make new iterations and replacements. Técnico Solar Boat

SR02 Updates Motor Due to some power issues that we had in the Monaco Solar & Energy Boat Challenge 2019, we decided to study our motors a little better. Theoretically, by their characteristics, we could use 8 kW of com- bined continuous power. However, after we tested them on our new TestBench, we found that the motors did not have the power indicated in their datasheet. Considering our findings, we changed the motors, tested, and ve- rified if the parameters present in the datasheet were fulfilled. With the final tests carried out on water we were finally satisfied with the performance of our motors. With the TestBench, we could also set up the parameters of the motor controllers that we use for optimizing the vessel. These new motors had to be installed on the gearbox that we al- ready had, so a new mounting bracket was machined. The new motors were tested in May and June, they performed as we ex- pected and with them, we were able to fly on foils for the first time. Steering system We were not satisfied with the performance of the steering system during the 2019 competitions, so we designed a new system that is easier to assemble and disassemble and makes it easier to steer with the forces that are applied to the propulsion column at high speeds. It is expected to be machined and tested this month. Técnico Solar Boat

Técnico Solar Boat

SR02 Updates Mppts A solar panel has an efficiency curve which depends on many fac- tors, such as temperature, and meteorological conditions. If we connect a solar panel directly to a battery, it will be on a random point, which will lead to reduced power efficiency As the weather conditions change and/or shadows cover the panels, we need a smart device to change the efficiency curve point where the solar panels are at, this curve always has a maxi- mum power point, and to track it we need an MPPT. An MPPT is an electronic DC to DC converter. This smart DC/DC has an algorithm for tracking the greatest efficiency point by changing the voltage the solar panels are at. One of the simplest algorithms consists of applying slight voltage changes in the panels and reading the current. The algorithm tracks the point where the product between voltage and current is the highest, thus the maximum power point. The MPPT will incre- ase or reduce the voltage until it obtains the highest power possi- ble, this point is constantly calculated to guarantee the top effi- ciency of the solar panels. Técnico Solar Boat

Solar Panels Laminator Being the vessel powered by solar energy, the solar panels are a fundamental part of them. Since last season, we decided to try to laminate our panels. This is a complicated process and requires a lot of investigation, since they are flexible panels. These panels have some requirements imposed by us: be flexible, very thin, light, and as efficient as possible. After one year and four months of research, we started to design the laminator. This laminator is a heated table, where it is possible to apply a vacuum to the surface. The panels are made up of several layers and each one is chosen so that the panel has the desired characteristics. We had a delay in construction due to COVID-19, but as soon as we can get back to work, we will finish the laminator design and laminate our first flexible solar panel. Técnico Solar Boat

Hydrogen Vessel The new prototype consists of the development of the propulsion system We are limited to 5 kWh of onboard energy. This new prototype is the first hydrogen vessel that TSB has developed. So as a result of all our work. Regarding the boat’s propulsion, it comes from the use of a fuel cell that c trical energy and heat. The two main components for the fuel cell’s functi

m and the vessel’s cockpit, which has 5 m of length and 2.5 m of beam. o, we are very excited and motivated to show our vessel in competition converts the internal energy contained in the fuel (hydrogen) into elec- ioning are the hydrogen and the oxygen.

Design & Composites The project stage was extremely important in order to define our main goals, to solve problems, and to ensure we follow all the te- chnical rules of the Energy Class. One of our defined main goals was to approach a more eco-friendly path by using materials, like flax fiber, core PET, and high bio-based resins. In addition, our curiosity regarding new materials and their mechanical properties inspired us to do laboratory tests in order to compare and choose the best combinations of materials. Técnico Solar Boat

Our construction stage for the hydrogen-powered vessel begun in February. We’ve repaired our cockpit moulds, machined some small components moulds (seat, steering wheel, headrest), and prepared the materials for our main laminations. We achieved good finishing moulds but, unfortunately, due to the coronavirus crisis, we had to interrupt the construction and advance other projects while in quarantine. Técnico Solar Boat

Fuel Cell & Hydro Hydrogen Production Because of the widespread knowledge concerning electrolysis the hydrogen production team has been quick to put together the com- ponents needed to build an electrolysis system capable of produ- cing enough hydrogen for our application. The system is already being produced and we count on having it ready by the end of this season. The hydrogen produced by this system will feed the proto- type fuel cell. Air Admission The air supply system was the first system to be fully defined. It is constituted by an air filter, a pump, and a humidifier. We are now on the break of purchasing this material. Radiator & Cooling This is the area where we performed the most CFD simulations. Mostly because we wanted to optimize our radiator size so that the cooling of the Fuel Cell has a high efficiency. The main components of this area are the pump and the radiator. Técnico Solar Boat

ogen Systems Fuel Cell Since the team's objective is to build its own components, we star- ted to investigate how we could build our own fuel cell. The results of this investigation were phenomenal and so we are finalizing a prototype fuel cell constituted by only two cells that will power a small RC vehicle. Técnico Solar Boat

Fuel Cell & Hydro Hydrogen Admission The hydrogen system suffered a total restructuring. A mistake happened when dimensioning the valves' size for the flow demand which obliged to redefine tubes and valves diameters. Técnico Solar Boat

ogen Systems Técnico Solar Boat

Acknowledgments We would like to thank all the support that has been given to us, both by the community and by our sponsors who have been incredible. Despite the difficult times we face, we never let our arms down and together we managed to continue the work we had planned and, thus, fulfill the objectives of this season. Coming soon In July, we will start the construction of our fourth vessel, a solar boat named São Rafael 03 (SR-03). This time, we want to develop a solar boat faster than the last one, but at the same time, we want to ensure it is efficient enough for endu- rance races. This summer we will have lots of news for you, follow us on social media, and stay updated. Hope you like it! Técnico Solar Boat