Integration of decentralized solar collectors in Dutch district heating networks

Most of the heat in Dutch district heating networks is produced by fossil fuels. In this study the limits and most promising configurations for the feed-in of solar heat from consumers have been investigated. The results have been evaluated in terms of total annual solar gain, solar gain per collector area, solar fraction, CO2 reduction and costs. To make sure the results are applicable to more than one network, several Dutch district heating networks and building types have been used to design a network model in Matlab and Simulink. In order to reach high solar fractions, the integration of storage is analysed as well. Three test networks have been used to show the influence of different building types. They contain 50 to 150 consumers which can all be adapted for different years of construction. These test networks have been chosen in such a way that their absolute heat losses are similar. However, the total demand varies due to the different types and amount of consumers. The simulations show that the economically best scenario is found for 400 m2 collector area placed at one apartment building and a 50 m3 buffer. In this scenario 22% of the annual heat demand of 150 consumers is replaced by solar heat. Based on the current consumer heat price the pay back time of the solar system is 14 years which seems promising. More importantly it can be avoided that 500 GJ of heat is produced in fossil fuelled kettles, especially when combined with smart buffering.Energy TechnologyProcess and EnergyMechanical, Maritime and Materials Engineerin