Interaction between wind turbines and heat pumps

Ea Energy Analyses and COWI in cooperation with Copenhagen Energy (now HOFOR) have carried out an analysis of the value of large heat pumps in interaction with wind power in the Copenhagen district heating system. The purpose of the analysis was to estimate the utility value of establishing heat pumps from both a socio-economic and project economic viewpoint. Various solutions are examined, including supply of electricity through direct connection of the wind turbines to the heat pump. An important parameter is the framework conditions for the heat pump, such as duties and tariffs imposed on the electricity consumed by the heat pump.

The calculations were carried out using the modelling tool Balmorel, which contains a detailed description of the CHP system in Copenhagen. The analysis shows, that a heat pump with a high COP of 5 can create a positive utility value, both from a socio-economic and project economic viewpoint. A high COP can be achieved by e.g. limiting the temperature rise on the output. The most valuable solution is achieved when connecting the heat pump to both the wind turbines (free of duties and tariffs) and the grid. In this case, a heat pump with a heat capacity of 30 MJ/s achieves approx. 4000 to 5000 full load hours a year. De extra investment needed for connecting the heat pump to both the grid and wind turbines is not analysed in this project.