Sustainable Heat Supply for Greenhouses with Heatpumps

The heating of greenhouses in Germany is yearly responsible for the emission of about 3 million tCO2eq. In the small horticultural city of Straelen in North-west Germany, the possibility to partially replace the heat supply of greenhouses with heat pumps instead of CO2-intensive coal and oil boilers has been investigated. Different scenarios based on the power of the heat pump and the type of source (air or ground) have been simulated and compared economically and ecologically. Over the lifetime of the whole system, the levelized cost of heat for a combined heat pump & gas boiler heating system is lower than the reference case (coal & gas boilers). The installation of a heatpump covering at least 70% of the yearly heat demand would reduce the CO2-emission from minimum 70%.