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This study investigates the performance of a novel desiccant air dehumidification and cooling cycle that utilises ground source heat exchange and flat plate photovoltaic thermal (PV/T) collectors (the GPVTDC system) to provide conditioned air. The system was modelled in TRNSYS using verified components with a focus on three climates: (i) an oceanic climate (Cfb) (ii) a humid sub-tropical climate (Cfa), and (iii) a hot semi-arid climate (BSh). The GPVTDC system pre-cools the entry air by utilising a ground source heat exchange. This allows the desiccant regeneration process to operate at low temperatures ranging from 43 °C to 62 °C, which enables the use of glazed water type PV/T collectors as the main heat source. The collectors were sized to match both thermal and electrical energy requirements to drive the GPVTDC system. The system was simulated for a whole year in each climate to provide fresh air ventilation, dehumidification and cooling process for an office space. Evaluation of the annual cooling performance of the GPVTDC system shows that it can maintain an office space within the thermal comfort zone for up to 93% of the time, with an average system cooling coefficient of performance (COP) between 9.6 and 16.3 for the three analysed climates. In addition, electrical energy saving up to 87% is achieved in comparison to a conventional dew point air dehumidification and cooling process. • Entry air pre-cooling enables low desiccant regeneration temperatures of 43–62 °C. • All thermal and electrical energy consumption can be provided by PV/T collectors. • High system cooling COP of 9.6–16.3 • Energy saving of 54–87% compared to a dewpoint dehumidification, cooling process. [ABSTRACT FROM AUTHOR]

One of the major obstacles to improving solar thermal cooling technologies is the high operating temperature requirements of most solar thermal cooling systems. This paper reviews recent advances that could reduce the required heat source temperatures for solar desiccant cooling to the range of 50°C–60°C. These approaches include (i) isothermal dehumidification (e.g. two-stage dehumidification or internal cooled dehumidification) and (ii) pre-cooling of the entry air with ambient heat sinks (e.g. indirect evaporative cooling or geothermal exchange). These techniques can potentially leads to a more thermodynamically efficient solution for utilising recovered heat from flat plate photovoltaic thermal (PV/T) collectors for desiccant regeneration. Analysis of the literature shows that obtainable outlet fluid temperatures from existing PV/T systems nearly match the low temperature desiccant cooling and dehumidification applications. Design and operation factors for achieving sufficiently high outlet fluid temperature in flat plate PV/T collectors include (i) maintaining low mass flow rate per collector area, (ii) addition of a glazed cover and (iii) hydraulic channel diameter optimisation. These factors are reviewed and case studies of complete solar PV/T desiccant cooling are examined. [ABSTRACT FROM AUTHOR]