Investigation of a small-scale solar linear Fresnel reflector-based polygeneration system for cost-effective power, cooling, and water solutions

Abstract

This study presents an investigation of a novel small-scale polygeneration system using a linear Fresnel reflector (LFR) in a direct steam generation (DSG) configuration, to simultaneously deliver electricity (100 kW), cooling (35 kW), and freshwater (23.6 m³/day). The system integrates an LFR solar field with a steam Rankine cycle, an ejector refrigeration cycle, and a multi-effect distillation unit, supported by a natural gas boiler for dispatchability. An energy, exergy, economics, and environment analysis was conducted using literature-validated thermodynamic models. The physical sizing constraints, geographical location, and design DNI were adopted from the Vallipuram pilot plant in India (12.572°N, 79.990°E). Additionally, a parametric analysis was conducted on different design and operational parameters. MATLAB, combined with the X Steam library, was used for simulation. The system achieved overall energy and exergy efficiencies of 26% and 14.85%, respectively. The LFR solar field is the major contributor to system exergy destruction, indicating potential performance improvement. Economic evaluation demonstrates a feasible levelized cost for all products and a positive net present value. The solar field mitigates gross CO₂ emissions of 1837.38 tons annually by displacing an equivalent amount of coal-fired energy. These findings support the conclusion that small-scale DSG polygeneration could be a sustainable option for meeting the water and energy needs of off-grid and remote communities that rely on expensive, polluting fuel sources.