Flying boat on solar power
9 minutes left. The deadline came closer and closer. Even though I already finished my motivation letter, a little part of me was still doubting. Am I making the right choice? Will the coming year really add to my development and above all: will it be fun?
My parents were a bit hesitant too. I mean the word “delay” commonly isn’t inherently positive. Frankly, they changed their minds very quickly once they saw the first solar boat build by Solar Boat Twente. All I can say is that this year has been great so far and I can’t wait to see our boat crossing the finish line in Monaco!
Deep down I always wanted to be part of a team that works towards one goal. An entire year you are working hard to work out ideas from concept to the final product. Especially once all is starting to take shape, you can be proud. Proud of the accomplishments as a team. Something that characterises Solar Boat Twente is that there is still room for realising complete new ideas. This year, for example, we decided to place the motor underwater in a special housing. This so called pod motor is one of our major projects and the application is quite unique in the solar boat scene. Commercially it isn’t applied much either. Nevertheless, we decided to take on the challenge together with a few partners. The motor will be custom made and housed in a nacelle, which is made out of milled aluminum. At first the design seemed quite doable. But then, a few weeks later, the real engineering kicks in! Out of the blue you have to solve problems you didn’t think of at first. That’s what makes being part of a student team interesting. Working out your idea from sketch to product and solving problems along the design process. Personally, that is one of the biggest reasons why I joined Solar Boat Twente.
The goal is to race for a podium position in the Solar Sport One competition in 2019. By the middle of the 21st century, harbours worldwide will be filled with yachts and motorboats powered by solar energy, that is the objective of the Solar Sport One competition. Besides, we try to encourage environmental awareness by the application of renewable energy in the maritime sector. The year basically is divided into 4 periods: designing, manufacturing, testing and racing. The design phase takes the longest: from September up to February. As the design and manufacturing phase are being completed, the coming months we will mainly focus on testing, visiting big events such as Hannover Messe, and eventually racing.
A race consists of three different aspects: endurance, slalom and sprint. During the endurance race the idea is to cover the largest possible distance in a given time. Then the slalom focuses on manoeuvrability and the sprint boils down to directing 10 kW of power through the electric motor. Finally, speeds up to 50 km/h can be reached during sprint while the cruise speed is set to 30 km/h. Instead of having one race, we have several. The first race is in Akkrum at the end of May and several more will follow in June. Then, at the beginning of July, the moment is finally there to participate in the World Championships in Monaco! Here we will compete in an endurance race, sprint and slalom. After the prize-giving ceremony will be have a fancy diner to conclude the hopefully successful race season!
Solar energy is harvested by the solar panels. Then a set of Maximum Power Point Tracking (MPPT) devices extract maximum available power from the solar cells. In order to measure the power generated by the solar deck and to be able to turn on/off single PV modules, a sensor with relays has been designed. The energy flows from the MPPTs to the battery pack or directly to the motor controller. The battery pack includes a Battery Management System (BMS), relay and some connection hardware. This way energy can be safely stored and utilised. From the battery the energy flows to the motor controller. This apparatus basically converts a DC current to an AC current, with which we can power the three-phase electric motor. Subsequently, the pod motor drives the propeller. Additionally, peripheral devices such as the board computer, data acquisition display, sensors, fans and a pump are part of the energy system.
Really, the electronic and software system is the beating heart of the entire boat. The energy flow scheme can be visualised as follows.
The energyflow diagram of the solar boat.
Solar energy is harvested by the solar panels. Then a set of Maximum Power Point Tracking (MPPT) devices extract maximum available power from the solar cells. In order to measure the power generated by the solar deck and to be able to turn on/off single PV modules, a sensor with relays has been designed. The energy flows from the MPPTs to the battery pack or directly to the motor controller. The battery pack includes a Battery Management System (BMS), relay and some connection hardware. This way energy can be safely stored and utilised. From the battery the energy flows to the motor controller. This apparatus basically converts a DC current to an AC current, with which we can power the three-phase electric motor. Subsequently, the pod motor drives the propeller. Additionally, peripheral devices such as the board computer, data acquisition display, sensors, fans and a pump are part of the energy system.
This year our electronics department focussed on realising a more efficient solar deck and improving the data acquisition. Currently Frank Somhorst and Sander Oosterveld are responsible for our electronics and software system. Sander mainly focuses on coding software which includes data acquisition and connection all the different interfaces such as the board computer, BMS, motor controller and hydrofoil control system. Besides, Sander has designed the PCBs. Frank has been busy with designing the power electronics system which comprises programming the BMS and motor controller, spot welding the battery pack and soldering all connections. In conclusion, being part of the electronics and software team gives the opportunity to combine both practical and design skills. For the coming year enough challenges lay ahead such as possibly realising two pod motors in combination with a contra-rotating propeller.
Do you want to be part of a highly motivated team in which you can come up with an idea and also realise it? Solar Boat Twente is looking for new members to form the third team since the foundation in 2016. Want to know more about what a year at Solar Boat Twente looks like? Get involved and visit our website to read more about this years experiences. Moreover, we will organise an interest lunch in the beginning of April. Make sure to check out our social media for further info and come by if you’re interested! Get involved and apply at apply@solarboattwente.nl.
