New Materials

Recap SYMBIOSIS deepdive – Duckweed in a circular economy

BlueCity Symbiosis Lowres-Jacqueline Fuijkschot-15

Gaining Insight in the Project of FlipTheCity: How Duckweed Becomes Tiles and the Power of Brainstorming

At SYMBIOSIS on the 13th of May 2022 at BlueCity, you could find yourself immersing into the idea of Flip the City, a start-up company that produces tiles made from duckweed. In this interactive deepdive, Emma Raijmakers and Eliza Scholtens, both part of the Flip the City team, pitched their idea. A diverse audience attended the deepdive, from master’s students of diverse disciplines to project designers and employees from the waterboard and municipality. Ideas were exchanged on how to refine steps and solidify Flip the City’s vision by discussing the complexities of a start-up and working with a seasonal waste stream product. 

Diving into the system of duckweed

Two years ago, the team of Flip the City won the Circular Challenge, a six-week challenge in which young professionals come up with a circular business idea based on an existing waste stream. Their challenge was: how can we use duckweed as a circular resource?. But what is duckweed? Maybe you know it as water lentils, or if you’re Dutch, kroos might ring a bell. It’s a plant living on the water surface which has been spreading increasingly due to rising temperatures and diminished water quality. It’s also a seasonal plant, primarily found in the warmer months. Duckweed contains a lot of nutrients – it is for example high in protein – but it also negatively affects the city’s image due to its smell and omnipresence. Therefore, the Province of South Holland entered duckweed as a waste stream in the Circular Challenge.

This is where Flip the City comes in with a perhaps counterintuitive solution: making tiles out of duckweed. With this idea, Flip the City kills two birds with one stone: it solves both the problem of excessive duckweed and produces tiles in a more sustainable and circular way. Those tiles are not meant to be walked on though,  but can replace normal ones, catering toward the Dutch tradition of Tegelwippen: replacing tiles with greenery in spring. Not only is making tiles out of the duckweed a valuable alternative to burning the duckweed and thereby creating CO2, but duckweed can even store CO2. Moreover, the kroostegels of Flip the City contain seeds of local plants. The duckweed becomes, by decomposing, the feeding ground for those seeds to grow, thereby enhancing biodiversity. A practical multipurpose all-in-one tile so to say.

Both the resource and seasonality of the product means having to deal with storage and timing of production, which can be difficult to do sustainably, with only a small team handling both production and research. During the deepdive, ideas on how to combat this surrounded the possibility of teaming up with other seasonal start-ups and practices to share storage spaces or incorporate production into other steps of the supply-demand cycle. Ideas flourished: How about drying tiles on citizens rooftops, thereby also incorporating and familiarizing them with the project, or using mobile machinery to press tiles on site?

Two takeaways from this conversation

Overall, one thing’s sure, being circular and sustainable while being a start-up can become difficult, especially due to missing connections and access to expert knowledge. And, let’s be honest, there’s an abundance of aspects to consider, so collaboration is needed. This was also one of the two main takeaways: Interdisciplinary input is valuable as it enables fresh perspectives. Plus, an outsider’s perspective can sometimes clear the fog and make new possibilities become apparent. So, if you want to contribute, don’t be shy to engage and attend one of BlueCity’s events!

The other take-away was the need for Flip the City to make a choice: focusing on ‘flipping the city’ by making it more sustainable, or focusing on solving the problem of the abundance of duckweed. This choice will impact other considerations and the problems to be considered. Whichever Flip the City chooses, one thing is sure: some first, valuable connections were made, and the team has a lot to think about! 

If you feel inspired by their mission, feel free to get more information and reach out to them by visiting their website. And if you’re up for a challenge, be sure to check out the circular challenge of BlueCity. Who knows, maybe you’ll end up founding a circular start-up yourself?

This blogpost was written by Jordis Wunder. She is a student-correspondent at the Design Impact Transition (DIT) platform, a strategic initiative from EUR aimed at supporting transformative education and research at the university. The DIT platform and BlueCity have teamed up with student-correspondents to spread the messages on circular economy and transformative academic work on the whole campus. Are you interested in the DIT platform and its mission? Or would you like to become a student-correspondent yourself? Then reach out to DIT, online.