For a decade, an exclusive partnership has linked 'Gemüsebau Steiner' and the Bavarian REWE markets. Their energy and lighting concept for their greenhouses has made them a flagship company throughout Europe. In an interview, Wolfgang and Florian Steiner discuss what makes their operation so unique.
Your concept was presented as groundbreaking for the entire industry at the REWE Group's stand at the Green Week. What makes your greenhouses so special?
Wolfgang Steiner: "For 95 percent, our greenhouses are heated by geothermal energy from the neighboring geothermal plant and the return flow of the district heating network of the Kirchweidach community. This is a reliable and constant heat source, independent of wind and weather throughout the year. The remaining five percent is obtained from the waste heat of a nearby biogas plant. With the help of a heat storage element, the heat can be used as required. The photovoltaic system for self-generated electricity on the roof of the operation halls supplies the greenhouses with power."
Florian Steiner: "We refrain from using chemical plant protection, rely exclusively on beneficial organisms, and use biodegradable ropes. We collect rainwater as well as condensation water from the greenhouses in a large basin and thus have an autonomous water balance. So, we do not consume CO₂ for heat supply or precious drinking water for irrigation. We have short transport routes to the warehouses of REWE and PENNY. This means we produce regionally, resource-saving, and environmentally friendly products. With this sustainable concept, we are unique in Germany."
In 2018, you decided to also grow organic products. What is the difference, cultivation-wise?
Florian Steiner: "The BIOhof Kirchweidach was also created in cooperation with REWE, as there was a high demand for regional organic products. In conventional cultivation, our plants grow on a coconut substrate, a waste product of coconut production. The organic plants grow in nutrient-rich topsoil and are fertilized with homemade compost, which is made from our plant residues. This creates a wonderful nutrient cycle."
In Emmerting, you started operating the first greenhouse in Germany with 100 percent LED lighting in 2020. What are the advantages?
Wolfgang Steiner: "This allows us to compensate for the fewer hours of sunshine in winter, achieve a longer, more intense ripening period, and can offer ripe, sweet tomatoes from the region even in winter. Compared to the previously common lamps, we save 38 percent of energy. The Emmerting community also benefits from the new lighting technology: Many households can be supplied with environmentally friendly district heating at a low cost through a heat line to the greenhouse."
Your company consistently attracts significant media interest, and in 2023, you won the Sustainability Impact Award. What is the basis of your success?
Florian Steiner: "This award makes us very proud as it honors our commitment to sustainability. And actually, we are still a newcomer; our operation has only existed for just under ten years! But it is a rounded concept, starting from the sustainable energy source, through the natural plant protection to the good, equal partnership with REWE."
Wolfgang Steiner: "Product quality also contributes to our success. Every day on the plant counts – our fruits are harvested fully ripe. Taste is our top priority. That's how we have to convince our customers."
What projects are you working on in 2024?
Wolfgang Steiner: "We have now drilled our own geothermal well. This will be put into operation in the fall. With this, we are also setting up a district heating concept for the entire region. Besides, we want to add more products to our range."
Source: Rewe Group
For more information:
www.gemuesebau-steiner.de