Modelling system integration of a micro solar Organic Rankine Cycle plant into a residential building

In the present energy scenario and considering the high share on global energy demand of buildings, small and micro-scale combined heat and power units powered by solar energy are considered a suitable solution for many industrial and civil applications, such as residential buildings. In this work a micro solar Organic Rankine Cycle plant is analysed. The system consists of a concentrated Linear Fresnel Reflectors solar field coupled with a phase change material thermal energy storage tank and a 2 kWe/18 kWth Organic Rankine Cycle system. In this work the integration of such system with a building is investigated in detail by means of a dynamic simulation model. In particular their interaction is analysed to assess its impact on the Organic Rankine Cycle electric and thermal performance. Furthermore, the building heating system optimization is evaluated aiming at minimizing the energy operational costs of the building. Results show the convenience of the proposed micro solar combined heat and power system when it works in trigeneration configuration. They highlight also that the operational strategy and the dynamic energy demand of the building affect the Organic Rankine Cycle performance and 26% higher electricity production is obtained with the integrated plant-building model compared to the plant without building integration. Regarding the building parameters design, they affect the energy cost only if they are varied simultaneously and their optimal set-up can allow up to 9% energy cost savings, thanks to a better exploitation of the available energy produced by the micro solar plant.