Symbiosis Opportunities Between Food And Energy System: The Potential Of Manure-Based Biogas As Heating Source For Greenhouse Production

The concept of symbiosis, a mutually beneficial relationship, can be applied to food and energy systems. Greenhouse systems and biogas plants are interesting technologies for food-energy symbiosis, because both are usually based in rural areas and offer opportunities for the exchange of materials (e.g., biomass waste from the greenhouse as input to biogas plants) and energy (heat from biogas co-generation for heating greenhouses). In this paper, the focus lies on manure resources for biogas in Switzerland, because manure amounts are high and currently largely underused. We provide a spatial analysis of the availability of manure as feedstock to biogas plants and heat source for greenhouses. In this feasibility study, we coupled the potential waste heat supply from manure-based biogas and the greenhouse peak heat demand. We quantified the area-based greenhouse heating demand for year-around tomato production (from 0.98 to 2.67 MW ha(-1)where the farms are located) and the available heat supply from manure-based biogas (up to 3,200 GJ a(-1)km(-2)). A total maximum greenhouse area of 104 ha could be sustained with manure-based biogas heat, producing 20,800 tonnes a(-1)tomatoes. This amounts to 11% of the total domestic tomato demand. Although the results are specific to Switzerland, our method can be adapted and also applied to other regions.