Hybrid energy networks and electrification of district heating under different energy system conditions

Abstract

As electricity systems world-wide are transitioning into increasing levels of variable renewable electricity sources, such as wind power and photovoltaics, increased electrification of other energy sectors has shown to be important for allowing a resource- and cost-efficient integration of these sources. Research has found electrification of district heating to be one of the more promising energy sectors for electrification in relation to integrating variable renewable electricity sources, as district heating allows for the utilization of varied use of different energy conversion technologies and low-cost energy storage solutions. Historically, district heating has mainly been interconnected to the electricity system via combined heat and power units, though research have found that with increasing levels of variable renewable electricity sources the need for electricity consuming conversion units, such as heat pumps, are becoming more important. In this, the national energy system effects of electrification of the district heating sector are investigated. Two future energy system scenarios for two different countries, being Austria and Denmark are made: one with a high degree of district heating utilization and one with a lower degree of district heating utilization. Both countries are expected to utilize increasing levels of variable renewable electricity sources, though the level and type of variable renewables are different due to differences of e.g. in availability hydro power solutions within the countries and the wind and solar resources available. As such, these two countries provide different perspectives on how electrification can be understood under different conditions.