Solar combined cooling, heating and power systems based on hybrid PVT, PV or solar-thermal collectors for building applications

Abstract

A modelling methodology is developed and used to investigate the technoeconomic performance of solar combined cooling, heating and power (S-CCHP) systems based on hybrid PVT collectors. The building energy demands are inputs to a transient system model, which couples PVT solar collectors via thermal store to commercial absorption chillers. The real energy demands of the University Campus of Bari, investment costs, relevant electricity and gas prices are used to estimate payback times. The results are compared to: evacuated tube collectors (ETCs) for heating and cooling provision; and a PV-system for electricity provision. A 1.68-MWp S-CCHP system can cover 20.9%, 55.1% and 16.3% of the space-heating, cooling and electrical demands of the Campus, respectively, with roof-space availability being a major limiting factor. The payback time is 16.7 years, 2.7 times higher than that of a PV system. The lack of electricity generation by the ETC-based system limits its profitability, and leads to 2.3 times longer payback time. The environmental benefits arising from the system’s operation are evaluated. The S-CCHP system can displace 911 tons CO2/year (16% and 1.4 × times more than the PV-system and the ETC-based system, respectively). The influence of utility prices on the systems’ economics is analysed. It is found that the sensitivity to these prices is significant.