On Local Matters this week we have a look at different urban farming initiatives. I had a visit at a rather innovative project – a greenhouse on the roof of the IFSB training institute in Bettembourg, to be exact on the roof of their canteen. The IFSB hosts the greenhouse, the company Neubuild and the CDEC, council for economic development of the construction sector are responsible. Marcus works for the CDEC and is responsible for the cultivation. He says: “Our daily work mainly is experimenting. We see what works, what doesn’t work. We experiment with light, water, with different kinds of plants. Now, we cultivate all kinds of salads, of basil. Every morning, I control the ph-value, the nutrients in the water, the water pressure to guarantee a certain degree of oxygen.”
Marcus is specialized in hydroponic cultivation. The plants grow in small pots, with the optimal substratum. They are connected to a water cycle, a big basin and a system of tubes. The basin collects rainwater. And the pipes get the water to the plants. The surplus of water that gets to the plants gets back in the cycle and is reused. At the same time, the greenhouse is connected to the aerial system of the building. The building feeds it the greenhouse with co2 and the plants convert it into oxygen. This way, the building emits less co2 than a usual building of this size. Romain Guillard is the project manager for the CDEC. “The questions we want to answer with this project are: Can a greenhouse on a roof be practical? The roofs are lost surfaces, they are not used sufficiently. The second question was. Is it realizable? We had to check the country’s laws, the technical problems and the costs. Our third question is: Is it lucrative? So, we explore different business models. On the one hand, there is the production, but we could also think about events, tours in the greenhouse, it can be used for scientific research.”
The project is called GROOF, Greenhouses to reduce CO2 on roofs. GROOF is a European Interreg funded project, it started in 2017. Eleven European project partners take part, including institutions in France, Belgium and Germany. These three countries as well have installed greenhouses on roofs to experiment. They exchange their results. Romain says: “Groof wants to establish guidelines, everything we find out, we learn, from the experiences and our coaching. We want to provide this information for future project leaders, to show them what works, what doesn’t, and where one should be careful.” The goal of the project is to explore possibilities to produce fresh food locally with low co2 emissions.