Technical Report Draft 1

Background

As stated in the Seabin Project website (n.d.), the main purpose of the V5 Seabin is to accomplish the goal of the Seabin team, which is to live in a world where water pollution is non-existent. The primary function of the V5 Seabin is to remove waste from calm water bodies. By teaming up with various ports such as Poralu Marine and Safe Harbour Marina, the Seabin team was able to rapidly distribute its product to all corners of the earth (Seabin Project, n.d.).

The Seabin is a microplastic-filtering device that is deployed mainly in marinas and ports to remove waste from the water body. It is a device “considerably smaller than the average municipal garbage bin” and can hold a maximum of 20 kg of waste (Hicks, 2018). A submersible water pump that is attached to the Seabin sucks water in from the surface and as water passes through, any waste larger than 2mm is left behind in the device’s catch bag. Additionally, the Seabin requires little attention to maintain it as the catch bag only needs to be emptied as needed. According to the Seabin Project under its Frequently Asked Questions, the coating of the device also uses a “non toxic and highly durable anti-fouling system” reducing its cleaning interval to a period of six to eight weeks.  

However, when it comes to the problem of marine and micro plastics pollution in water bodies, the main complication that directly affects the ecosystem develops when the wildlife in the waters ingest micro plastics, one of the three main categories of plastic pollutants. These micropollutants can rapidly climb up the food chain and be eaten by humans as well. As the Seabin is currently situated where wildlife is minimal (Seabin Project, n.d.), its effectiveness in tackling the main problem of micro plastics is vastly limited.

Seabins are currently limited to marinas and ports because of its power source. According to the Seabin’s website (n.d.), the Seabin has to be plugged into a constant power supply of 110/220V and that the “Maximum distance to an electric energy supply point is 6 meters”. The current Seabin is limited to areas where a wired power source is located within the product’s vicinity like marinas and ports. With that said, by implementing modifications to the power supply of the Seabin, the Seabin Project can bring its product offshore to rivers or seas where it can have the highest impact on reducing pollutants on the earth's waters.

An ideal microplastic-filtering device is equipped with an underwater turbine to make use of the tidal motion to power the suction mechanism and pull micro-pollutants into an in-built filter, preventing the pollutants from spilling back out into the waterbody.

Problem statement 

However, one of the most viable products currently in the market, the Seabin, still needs to be permanently plugged into a 110/220V power outlet to power its suction mechanism (Seabin Project, n.d.) and is thus confined to places where electricity is readily available such as marinas and ports. With the implementation of an underwater turbine, the suction mechanism in the filtering device can be sustained as long as there is a constant current flow in the water body, allowing devices such as the Seabin to be brought offshore to remote water bodies in the world.

Purpose statement

The purpose of this report is to advise the Seabin Project team to integrate the recommended modifications to their products as it will play a crucial part in strengthening the adaptability of the Seabin.

Current and Proposed Solution

Current

The existing Seabin has to be connected to an electric energy supply point of 110/220V, 500W to operate (Seabin Project, n.d.). The default Seabin comes with a 6m long electrical cable and any extension needs to be modified by the user manually. This limits the Seabin to ports and marinas and vastly reduces its effectiveness. There have also been trials on adapting Solar panels onto the Seabin to allow the product to be implemented offshore as seen in Image 1 (Calleja, 2019). However, factors like shading, instability, battery infrastructure (Ahmad, 2016) and occupancy space make this solution cumbersome and suboptimal in the long run.

Image 1: Seabin with Solar panel adaptation.

Proposed

A hydro turbine produces electricity with the help of the natural tide of the water (Donev, J. et al, 2018). As the Seabin is deployed in the water, changing the source of power to a hydro turbine instead of a power socket would be the ideal solution. Hydro turbines come in a myriad of sizes and variations, which makes finding a compatible hydro turbine challenging. The best plan for the Seabin team would be to design a small prototype, test it and develop it. The final design would be able to produce 110/220V, anchor the Seabin and run effortlessly without any major issues. One product that the Seabin team can take reference from while building their hydro turbine is the SeaUrchin Tidal Turbine, shown in image 2. 

 Image 2: SeaUrchin Tidal Turbine

Benefits

The incorporation of an underwater turbine as a power source replacement will significantly increase the Seabin’s adaptability as it will allow the device to be brought out of marinas and ports and into seas and other water bodies.

For starters, having an underwater turbine means that the device will not have to rely on a power socket to power its suction mechanism. Rather, it will take advantage of its environment and use the water body’s tide to generate its own self-sustaining energy. Drawing energy from the water is also more dependable compared to other natural sources of energy like solar energy, which is affected by the sun’s positions, and wind energy, which is unpredictable especially if the device is deployed in places with no open space. Water is also denser than air, allowing the underwater turbine to generate the same amount of energy as a windmill “but at slower speeds and over less area” (Clark, n.d.).

Secondly, the underwater turbine powering the Seabin is of a small scale and does not require as much space as a solar panel or windmill as the suction mechanism only requires “2.5amps @ 500 watts” (Seabin Project, n.d.), making its deployment in remote locations more convenient. In addition, the small space taken up by the underwater turbine could allow for multiple devices to be installed in the same location, increasing the filtration’s area of the effect greatly.

Limitations

The main challenges of adapting a hydro turbine onto the Seabin are the increase in weight, cost and the corrosive seawater environment (Ahmad. 2016). The addition of a hydro turbine with the required power rating would add approximately 57kg (Kojima, 2014) onto the product and as the Seabin operates at the surface of the water, the increase in weight would require the Seabin to increase its buoyancy devices in order to remain at the surface of the water. 

One of the main challenges faced by all hydro energy power sources is the harsh sea condition and environment. Seawater, which is very corrosive, is constantly exerted onto the moving parts of the hydro-generator like the turbine blades causing the components to corrode and rust rapidly (Ahmad, 2016). Particles like sand carried in the water also quickly erode the components in the hydro turbines. The adaptation of hydro turbines onto the Seabin will definitely increase the cost of the product. This is because hydro turbine components are relatively expensive as they have to be durable enough to withstand the harsh sea conditions. 

Research Methods

Methodology

The team decided to use secondary research to source information that is crucial and relevant for the report.

Secondary Research

To begin with, the team decided to use the information found in the Seabin project website as a reference for elaborating on the benefits and functionality of the Seabin. Following that, the team used the google search engine to find sources regarding any modification made onto the Seabin. This would help to show the efforts made by the Seabin team to improve the current model. Lastly, along with google search engine, ScienceDirect was also used to find online technical reports and articles regarding hydro turbines and its benefits. 

Conclusion

As the dangers of micro plastics continue to grow and with micro pollutants finding more ways to enter our water bodies, the micro plastic filtering products on the market have to be just as adaptive as well. Even though the Seabin does not have an area of effect as large, or the adaptive ability as complex as other micro plastic filtering products, it is still one of the most cost-effective devices on the market. With the Seabin’s endless modification possibilities, it’s potential to grow is also immense. 

Improvements in engineering composite materials like carbon fiber will help tackle the challenge of the corrosive seawater conditions and allow underwater turbines to operate even in low tidal currents, increasing the Seabin’s operational ability once the turbine has been incorporated into the Seabin’s design. Although this modification would result in a price increase for the Seabin (estimated 1.5 - 2 times of its current cost), the operational cost of the device as a whole, which currently runs at 3USD per day (Seabin Project, n.d.), would be significantly reduced. Additionally, the Seabin would still remain as one of the most affordable marine cleaning devices available on the market. 

The team believes that with the incorporation of the underwater turbine, the Seabin will not only be a groundbreaking micro plastic filtering device but a key solution to the world’s water pollution problem.