Heat dispatch centre – Symbiosis of heat generation units to reach cost efficient low emission heat supply

Highlights: • Sustainable heat sources underlie constraints, hence interconnection is essential. • Temperature-wise series-connection allows usage of low temperature heat sources. • Heat analysis must be based on heat load by temperature level instead of load only. • Seasonal changes in heat demand call for variations in supply unit interconnection. -- Abstract: The application of renewable heat supply technologies underlies various constraints. To overcome these limitations to their application in this research, an interconnection of different heat sources in the so-called Heat-Dispatch-Centre is derived from the main characteristics of renewable heat supply technologies. A season-dependent operation state of generation and storage units allows low-emission and efficient heat supply. In addition, alternative connection possibilities are discussed and a visualization method for an analysis of heat generation units connected in series is introduced. For an exemplary network an overall primary energy factor of 0.09 and a specific CO₂ emission factor of 27 g_CO2/kWh is reached, with costs of overall heat generation at 11–12 €ct/kWh. In contrast to this, a parallel connection of the heat sources reduces overall efficiency, increases the costs to 13 €ct/kWh and increases the CO₂-emissions in the overall energy supply system by decreasing renewable electricity infeed into the grid.