Shower water as a resource in food production: In the vertical hydroponics farm in Berlin's Gleisdreieck Park, salads, edible flowers and herbs are to be cultivated hygienically in an impeccable manner
For the first time in Berlin, a vertical hydroponics farm / local water recycling plant combination was set up in the urban space. Scientists and students of the TU Berlin want to use it to investigate whether food such as lettuce, cabbage, edible flowers and herbs can be produced with treated shower water and consumed without any health risks. The vertical hydroponics farm "Shower-Tower 61" is located in the beach volleyball facility "Beach 61" of the Gleisdreieck Park, not far from Potsdamer Platz.
Hydroponics means that the plants are grown exclusively in an aqueous nutrient solution - without soil. What is new about this vertical hydroponic farm is that shower water, i.e. wastewater, becomes a resource and is to be used for food production. The vertical farm consists of eight two-metre high, white, square columns. These columns are located directly on the back wall of the showers at the beach volleyball court. In each column, 16 planting tubes were inserted. The pots with the plants are put into them. They grow in net pots and are stabilized by expanded clay and a root flow. The treated and nutrient-enriched shower water trickles into the columns from above and wets the roots that protrude into them. This supplies the plants with water and nutrients. The vertical hydroponics farm is suitable for growing salads, herbs such as basil, cabbage such as pak choi and red kale, beets such as chard and edible flowers.
Explore the benefits of real laboratories
The farm, also known as "Reallabor Mobile Blau Grüne Infrastruktur", was designed and built together with students from the project workshop "Roof Water-Farm tu-project" under the direction of Dr. Grit Bürgow, the student coordinator Andreas Horn and the architecture student Gabriel Sigler. It is a prototype. The research questions to be investigated using this "Reallabor Mobile Blau Grüne Infrastruktur" are embedded in the research project "Garden Production. Urban Gardens and Parks: Multidimensional Services for a socially, ecologically and economically sustainable area and material flow management".
The "Garden Production" project is investigating in four real-world laboratories how the significance of gardens and parks for the urban climate, biodiversity and the quality of life of people can be incorporated into political decisions in order to make urban land management more sustainable. In addition, research is being conducted into how social exchange, integration, participation and transformative learning can be promoted with such real-world laboratories. "Garden Production" is managed by the Institute for Ecological Economy (IÖW) Berlin.
The advantages of a vertical farm
"There are four questions we want to analyze with our farm. Firstly: Is it possible to treat shower water with current technologies in such a way that it can be used for food production and that the lettuces and herbs are completely safe for consumption? Second: Is such a vertical hydroponic farm suitable for local commercial and non-commercial food production in an urban environment like Berlin? Thirdly: Is it possible to involve the population in such a project on a long-term basis with the aim of ensuring that such blue-green infrastructures are operated and used by the people themselves in the future? Fourth: What effects does such a hydroponics farm combined with reed raised beds with evaporation effects have on the urban microclimate," says Grit Bürgow. The aim of answering these questions is to find solutions for climate-positive urban development.
In order to prove that the water treatment of grey water, in this case shower water, can be coupled with food production and that food that is harmless to health can be produced with treated shower water, the water must meet the DIN standard for irrigation water.
The advantage of such a vertical farm is that it does not take up urban areas, which are rare and expensive, but can be installed on facades and house walls. In the case of the TU "Shower Tower 61", the back wall of the showers is used. "This is very effective," says Grit Bürgow.
Is it possible to involve the population in the project?
Since the farm sees itself as a real laboratory, i.e. research is conducted directly in the urban space, Grit Bürgow, Andreas Horn and Gabriel Sigler are also in close contact with the operators of the bar of "Beach 61". "This exchange is important in order to find out what acceptance such innovative ideas for urban food production meet with among the population, whether the operators are interested in using the salads and herbs in their beach bar, and whether it would be a realistic scenario for them to manage such a farm with or even under their own management after the end of the real lab research". The added value would include short transport routes and fresh herbs for pizza and cocktails.
The "Garten Production" project is funded by the Federal Ministry of Education and Research as part of the "Resource-efficient urban quarters for the future" funding measure.
For more information:
Dr. Grit Bürgow
TU Berlin
Fachgebiet Städtebau und Siedlungswesen
E-Mail: grit.buergow@tu-berlin.de