A novel solar trigeneration system integrating PVT (photovoltaic/thermal collectors) and SW (seawater) desalination: Dynamic simulation and economic assessment

The paper investigates the integration of renewable energy sources and water systems, presenting a novel solar system producing simultaneously: electrical energy, thermal energy, cooling energy and domestic water. Such system is designed for small communities in European Mediterranean countries, rich in renewable sources and poor in fossil fuels and water resources. The polygeneration system under analysis includes PVT (photovoltaic/thermal solar collectors), a MED (multi-effect distillation) system for SW (seawater) desalination, a single-stage LiBr–H2O ACH (absorption chiller) and additional components, such as storage tanks, AHs (auxiliary heaters) and BOP (balance of plant) devices. The PVT produces simultaneously electrical energy and thermal energy. The electrical energy is delivered to the grid, whereas the thermal energy may be used for space heating and/or domestic HW (hot water) production. As an alternative, the solar thermal energy can be used to drive an ACH, producing CHW (chilled water) for space cooling. Finally, the solar energy, in combination with the thermal energy produced by an auxiliary biomass-fired heater, may be used by the MED system to convert SW into potable water. The system is dynamically simulated by means of a zero-dimensional transient simulation model. A thermo-economic analysis is also presented, aiming at determining the optimal values of the most important design variables.