Innovative utilization of waste heat from horticulture and industry for district heating supply

Challenge

Industrial production of flowers and food in greenhouses in Danish horticulture represents a huge energy source, as the greenhouses act as solar collectors that utilize the greenhouse effect to capture the sun's rays and convert solar radiation into heat. Much more than the greenhouses themselves can utilize. To put the potential into perspective, the excess heat vented from the 1.8 million m² of greenhouses connected to the Fjernvarme Fyn network could theoretically cover the total demand in the Fjernvarme Fyn supply area. However, this would require an enormous seasonal heat storage system.

Solution

The project is a feasibility study, where the technical and economic benefits of three functional concepts are developed and optimized. The three functions are:

• Increasing the supply temperature to greenhouse horticultures, thus reducing heat loss in transmission lines.
• Dehumidifying the greenhouses during the heating season, thereby reducing the energy consumption of the greenhouses.
• Producing heat for the horticulture and the district heating company's other consumers, thus increasing the district heating company's production capacity.

Impact

The completion of this project will establish the framework and data foundation for applying for, for example, an EUDP/GUDP project or starting a demonstration project funded by the project partners, to set up one or two demonstration plants.

For the heat pump supplier, the demonstration projects will help open a new market. Greenhouse horticultures in neighboring countries, especially the Netherlands, will need to meet similar climate goals as those in Denmark. In these countries, it will be ideal to replace dehumidification and heating with natural gas using heat pumps.

The project is co-financed by the Ministry of Education and Research.