Performance Assessment of District Energy Systems with Common Elements for Heating and Cooling
The assessment of a DHC system, which provides both heating and cooling, is challenging when the same equipment or system elements are used for purposes of producing heating and cooling, either simultaneously or alternatively. This is particularly the case for complex systems, which involve different energy sources and technologies in a single ensemble of a district energy system. Many components of such a system may be used for both heating and cooling: reversible heat pumps, heat generation or recovery applied to thermally driven cooling technologies, geothermal probes coupled with ground source heat pumps, and photovoltaics among other. Moreover, a growing endeavour of energy vector coupling, including renewable heat, electricity, green hydrogen, and syngas, is going to lead to even more complex district energy systems.
As for now, there is no comprehensive methodology for performance analysis of combined DHC systems.
This paper presents a methodology for calculating different DHC key performance indicators (KPIs), distinguishing between heating and cooling ones. A total of 11 indicators are organised under four categories: energy, environment, economy and socio-economy. The methodology proposes a demand-based and an investment-based share factors that facilitate the heating and cooling KPI calculation.