The present work is focused on the development of a simulation model for an existing co-generation power plant, which utilizes a solar thermal field with parabolic trough solar collectors coupled to an ORC engine. The power plant is modeled in TRNSYS v.17 software package and its performance has been validated with real operating conditions. The simulated system (CSP field and ORC engine) is part of a larger hybrid power plant located near “Ziloti” village of the Municipality of Xanthi, in northeastern Greece. The construction of the hybrid power plant was funded by the Strategic Co-Funded Project of the European Territorial Cooperation Program Greece-Bulgaria 2007-2013 with the acronym ENERGEIA. The power plant simulated in this paper includes a 234 kW_th solar parabolic trough collectors (PTC) field, a 5 m³ thermal energy storage tank and a 5 kW_e ORC engine, for production of thermal and electrical energy. The results of the simulations present small deviation in contrast to the real operating data of the CSP power plant coupled on the ORC engine, therefore simulation model is considered as reliable.

This paper discusses the techno-economic performance of installed renewable energy technologies in students’ residences of Democritus University of Thrace, in Kimmeria, Xanthi, North Greece. The students’ residences building complex includes eleven (11) buildings of total area of 14,819.09 m² and accommodate 630 students. The RES technologies installed, include a hybrid solar thermal/biomass system for heating, cooling and domestic hot water of the students’ residences buildings and one amphitheater, a geothermal heat pumps system for heating and cooling of a restaurant, an autonomous PV system and one small vertical axis wind turbine. The above interventions were accomplished under “REUNI” project that was funded by EEA and Norway Grants program – GR03-Renewable Energy Technologies. The present study elaborates the operational results of almost two years of the RES technologies installed and highlights their techno-economic performance, through analysis of the collected operational data. The building complex of the students’ residences of DUTH in Kimmeria has managed to operate for its thermal and cooling energy demand with hundred per cent (100%) renewables throughout a year, resulting in significant energy costs and CO₂ reduction. However, the operation and maintenance cost of the installed systems has been underestimated, resulting in increased number of days of unavailability. The results highlight the need to increase solar energy penetration, as well as the need for subsidy in order to compete with the fossil fuel technologies. The development of such systems that utilize renewable energy sources is considered as a priority for the increase of share of RES in the building sector. The experience from the operation of such system is valuable for the promotion of renewable energy in the built environment.